# Release 15.18

## Release date:

2026-05-14

This release contains a variety of fixes from 15.17. For information about new features in major release 15, see release-15.

## Migration to Version 15.18

A dump/restore is not required for those running 15.X.

However, if you are upgrading from a version earlier than 15.14, see release-15-14.

## Changes

- Prevent unbounded recursion while processing startup packets (Michael Paquier) § §

  A malicious client could crash the connected backend by alternating rejected SSL and GSS encryption requests indefinitely.

  The PostgreSQL Project thanks Calif.io (in collaboration with Claude and Anthropic Research) for reporting this problem. (CVE-2026-6479)

- Fix assorted integer overflows in memory-allocation calculations (Tom Lane, Nathan Bossart, Heikki Linnakangas) § § § § § § § § § §

  Various places were incautious about the possibility of integer overflow in calculations of how much memory to allocate. Overflow would lead to allocating a too-small buffer which the caller would then write past the end of. This would at least trigger server crashes, and probably could be exploited for arbitrary code execution. In many but by no means all cases, the hazard exists only in 32-bit builds.

  The PostgreSQL Project thanks Xint Code, Bruce Dang, Sven Klemm, and Pavel Kohout for reporting these problems. (CVE-2026-6473)

- Reject over-length options in `ts_headline()` (Michael Paquier) §

  The `StartSel`, `StopSel` and `FragmentDelimiter` strings must not exceed 32Kb in length, but this was not checked for. An over-length value would typically crash the server.

  The PostgreSQL Project thanks Xint Code for reporting this problem. (CVE-2026-6473)

- Guard against malicious time zone names in `timeofday()` and `pg_strftime()` (Tom Lane) § §

  A crafted time zone setting could pass `%` sequences to `snprintf()`, potentially causing crashes or disclosure of server memory. Another path to similar results was to overflow the limited-size output buffer used by `pg_strftime()`.

  The PostgreSQL Project thanks Xint Code for reporting this problem. (CVE-2026-6474)

- When creating a multirange type, ensure the user has `CREATE` privilege on the schema specified for the multirange type (Jelte Fennema-Nio) §

  The multirange type can be put into a different schema than its parent range type, but we neglected to apply the required privilege check when doing so.

  The PostgreSQL Project thanks Jelte Fennema-Nio for reporting this problem. (CVE-2026-6472)

- Use timing-safe string comparisons in authentication code (Michael Paquier) § §

  Use `timingsafe_bcmp()` instead of `memcpy()` or `strcmp()` when checking passwords, hashes, etc. It is not known whether the data dependency of those functions is usefully exploitable in any of these places, but in the interests of safety, replace them.

  The PostgreSQL Project thanks Joe Conway for reporting this problem. (CVE-2026-6478)

- Mark `PQfn()` as unsafe, and avoid using it within libpq (Nathan Bossart) §

  For a non-integral result type, `PQfn()` is not passed the size of the output buffer, so it cannot check that the data returned by the server will fit. A malicious server could therefore overwrite client memory. This is unfixable without an API change, so mark the function as deprecated. Internally to libpq, use a variant version that can apply the missing check.

  The PostgreSQL Project thanks Yu Kunpeng and Martin Heistermann for reporting this problem. (CVE-2026-6477)

- Prevent path traversal in pg_basebackup and pg_rewind (Michael Paquier) §

  These applications failed to validate output file paths read from their input, so that a malicious source could overwrite any file writable by these applications. Constrain where data can be written by rejecting paths that are absolute or contain parent-directory references.

  The PostgreSQL Project thanks XlabAI Team of Tencent Xuanwu Lab and Valery Gubanov for reporting this problem. (CVE-2026-6475)

- Guard against field overflow within `contrib/intarray`'s `query_int` type and `contrib/ltree`'s `ltxtquery` type (Tom Lane) § §

  Parsing of these query structures did not check for overflow of 16-bit fields, so that construction of an invalid query tree was possible. This can crash the server when executing the query.

  The PostgreSQL Project thanks Xint Code for reporting this problem. (CVE-2026-6473)

- Guard against overly long values of `contrib/ltree`'s `lquery` type (Michael Paquier) §

  Values with more than 64K items caused internal overflows, potentially resulting in stack smashes or wrong answers.

  The PostgreSQL Project thanks Vergissmeinnicht, A1ex, and Jihe Wang for reporting this problem. (CVE-2026-6473)

- Prevent SQL injection and buffer overruns in `contrib/spi` (Nathan Bossart) §

  `check_foreign_key()` was insufficiently careful about quoting key values, and also used fixed-length buffers for constructing queries. While this module is only meant as example code, it still shouldn't contain such dangerous errors.

  The PostgreSQL Project thanks Nikolay Samokhvalov for reporting this problem. (CVE-2026-6637)

- Check for nondeterministic collations before assuming that an equality condition on a collatable type implies uniqueness (Richard Guo) § §

  Numerous planner optimizations assume that, for example, at most one table row can satisfy `WHERE x = 'abc'` if there is a unique index on `x`. However this conclusion is unsafe in general if the index and the `WHERE` clause have different collations attached. It is safe when both collations are deterministic, because that property essentially requires that equality of two strings means bitwise equality. But nondeterministic collations don't act that way, so that optimizing on the assumption of unique matches can give wrong query answers if either the `WHERE` clause or the index has a nondeterministic collation.

- Fix incorrect handling of `NEW` generated columns in rule actions and rule qualifications (Richard Guo, Dean Rasheed) §

  Previously, such column references would produce NULL in `INSERT` cases, or be equivalent to the `OLD` value in `UPDATE` cases.

- Fix spurious generated columns are not supported in COPY FROM WHERE conditions errors (Tom Lane) §

  Use of a system column in a `COPY FROM WHERE` condition could sometimes incorrectly report this error.

- Correctly report a serialization failure when `MERGE` encounters a concurrently-updated tuple in repeatable-read or serializable mode (Tender Wang) §

  Previously, such cases behaved the same as in lower isolation levels.

- Fix `CREATE TABLE ... LIKE ... INCLUDING STATISTICS` for cases where the source table has dropped column(s) (Julien Tachoires) §

  In such cases, extended statistics objects could be copied incorrectly, or the command could give an incorrect error.

- Allow `ALTER INDEX ... ATTACH PARTITION` to mark the parent index valid if appropriate (Sami Imseih) §

  There are edge cases in which a partitioned index might remain marked as invalid even when all its leaf indexes are valid. This change provides a mechanism whereby a user can correct such a situation without resorting to manual catalog updates.

- Fix `ALTER FOREIGN DATA WRAPPER` to not drop the wrapper object's dependency on its handler function (Jeff Davis) §

- Disallow making a composite type be a member of itself via a multirange (Heikki Linnakangas) §

  We already forbade such cases when the intermediate type is a domain, array, composite type, or range; but multiranges were overlooked.

- Fix datum-image comparisons to be insensitive to sign-extension variations (David Rowley) §

  This fixes some situations that previously led to could not find memoization table entry errors or wrong query results.

- Fix incorrect logic for hashed `IN`/`NOT IN` with non-strict equality operator (Chengpeng Yan) §

  The previous coding could crash or give wrong answers. All built-in data types have strict equality operators, so that this issue could only arise with an extension data type.

- Truncate overly-long locale-specific numeric symbols in `to_char()` (Tom Lane) §

  If a locale specified a currency symbol, thousands separator, or decimal or sign symbol more than 8 bytes long, a buffer overrun was possible. No such locales exist in the real world, and it's impractical for an unprivileged attacker to install a malicious locale definition underneath a Postgres server; but for safety's sake check for overlength symbols and truncate if needed.

- Prevent buffer overruns when parsing an affix file for an `Ispell` dictionary (Tom Lane) § §

  A corrupt or malicious affix file could crash the server. This is not considered a security issue because text search configuration files are presumed trustworthy, but it still seems worth fixing.

- Guard against integer overflow in calculations of frame start and end positions for window aggregates (Richard Guo) §

  Very large user-specified offsets (close to INT64_MAX) could result in errors or incorrect query results.

- Fix incorrect behavior of `pg_stat_reset_single_table_counters()` on a shared catalog (Chao Li) §

  Such cases had a side-effect of resetting the current database's `stat_reset_timestamp`, which was unintended.

- Fix buffer overread when `pglz_decompress()` receives corrupt input (Andrew Dunstan) §

  It was possible to read a few bytes past the end of the input, which in very unlucky cases might cause a crash.

- Ensure that tuplestore data structures are internally consistent even after an error (Tom Lane) §

  The code was previously careless about this, which is fine most of the time but is problematic for the tuplestore backing a `WITH HOLD` cursor. In v15 and before this leads to easily-reproducible crashes; later branches are not known to be vulnerable, but it seems best to preserve consistency in all.

- Fix premature NULL lag reporting in pg_stat_replication (Shinya Kato) §

  The lag columns frequently read as NULL even while replication activity was happening.

- Avoid rare flush failure when working with non-WAL-logged GiST indexes (Tomas Vondra) §

  A non-logged GiST index could nonetheless sometimes produce xlog flush request `n/nnnn` is not satisfied errors, due to incorrect selection of a fake LSN to represent an insertion point.

- Fix underestimate of required size of DSA page maps for odd-size segments (Paul Bunn) §

  This miscalculation led to out-of-bounds accesses and hence server crashes.

- Fix possible server crash when processing extended statistics on expressions of extension data types (Michael Paquier) §

  NULL pointer dereferences were possible if the data type's typanalyze function does not compute any useful statistics. No in-core typanalyze function behaves that way, but extensions could.

- If the startup process fails, properly shut down other child processes before exiting the postmaster (Ayush Tiwari) §

  The handling of this situation relied on a long-obsolete assumption that no other postmaster children exist while the startup process is running, so that immediate postmaster exit is acceptable. Orphaned children would eventually notice the postmaster's death and exit on their own, but a cleaner shutdown procedure is desirable.

- Fix race condition between WAL replay of checkpoints and multixact ID creations (Heikki Linnakangas) §

  A standby server following WAL from a primary of an older minor version could get into a crash-and-restart loop complaining about could not access status of transaction.

- Prevent indefinite wait in shutdown of a walsender process (Anthonin Bonnefoy) § §

  At shutdown of a cluster that is publishing logical replication data, the walsender waits for all pending WAL to be written out. But it did not correctly request that to happen, so that in some cases this could become an indefinite wait.

- Ensure that changes to tables' free space maps are persisted during recovery (Alexey Makhmutov) §

  Previously, while WAL replay did update the free space map while replaying operations that should change it, the map page buffer did not get marked dirty if checksums are enabled, so that the changes might never get written out. On a standby server, over time this would result in a map wildly at variance with the table's actual contents. While the map is only used as a hint, this condition could cause significant performance degradation for some period of time after the standby server is promoted to be active, until most of the map has been repaired by updates.

- Fix crashes in some ecpg functions when called without any established connection (Shruthi Gowda) §

- Fix assorted bugs in backup decompression and tar-parsing code (Andrew Dunstan, Tom Lane, Chao Li) § § §

  The decompression and tar-file reading code used in pg_basebackup and pg_verifybackup mishandled tar-file padding data, could corrupt LZ4-compressed data in edge cases, failed to check for some unusual error conditions, failed to exit after compression/decompression errors (leading to cascading error reports), and leaked memory.

- In pg_upgrade, take care to use the correct protocol version when connecting to older source servers (Jacob Champion) §

  This could be problematic when attempting to upgrade from a pre-2018 server.

- In `contrib/basic_archive`, allow the archive directory to be missing at startup (Nathan Bossart) §

  Previously, the setting of `basic_archive.archive_directory` was rejected if it didn't point to an existing directory. This is undesirable because archiving will be stuck indefinitely, even if the directory appears later.

- Fix `contrib/ltree` to cope when case-folding changes a string's byte length (Jeff Davis) §

  Previously, `lquery` patterns specifying case-insensitive matching might fail to match labels they should match.

- In `contrib/pg_stat_statements`, don't leak memory if an error occurs while parsing the `pgss_query_texts.stat` file (Heikki Linnakangas) §

- In `contrib/postgres_fdw`, avoid crash due to premature cleanup of a failed connection (Etsuro Fujita) §

  If a remote connection fails abort cleanup, we can't use it any longer. But delay closing the connection object until end of transaction, because there might still be references to it within data structures such as open cursors.

- Update time zone data files to tzdata release 2026b (Tom Lane) §

  British Columbia (America/Vancouver) will be on year-round UTC-07 (effectively, permanent DST) beginning in November 2026. This release assumes that their TZ abbreviation will be `MST` from that time forward. That seems likely to change, but it's unclear what new abbreviation will be used. Also a historical correction for Moldova: they have followed EU DST transition times since 2022.

## Release 15.17

## Release date:

2026-02-26

This release contains a small number of fixes from 15.16. For information about new features in major release 15, see release-15.

## Migration to Version 15.17

A dump/restore is not required for those running 15.X.

However, if you are upgrading from a version earlier than 15.14, see release-15-14.

## Changes

- Fix failure after replaying a multixid truncation record from WAL that was generated by an older minor version (Heikki Linnakangas) §

  Erroneous logic for coping with the way that previous versions handled multixid wraparound led to replay failure, with messages like could not access status of transaction. A typical scenario in which this could occur is a standby server of the latest minor version consuming WAL from a primary server of an older version.

- Avoid incorrect complaint of invalid encoding when `substring()` is applied to toasted data (Noah Misch) § § §

  The fix for CVE-2026-2006 was too aggressive and could raise an error about an incomplete character in cases that are actually valid.

- Fix `pg_stat_get_backend_wait_event()` and `pg_stat_get_backend_wait_event_type()` to report values for auxiliary processes (Heikki Linnakangas) §

  Previously these functions returned NULL for auxiliary processes, but that's inconsistent with the pg_stat_activity view.

- Fix casting a composite-type variable to a domain type when returning its value from a PL/pgSQL function (Tom Lane) §

  If the variable's value is NULL, a cache lookup failed for type 0 error resulted.

- Fix potential null pointer dereference in `contrib/hstore`'s binary input function (Michael Paquier) §

  `hstore`'s receive function crashed on input containing duplicate keys. `hstore` values generated by Postgres would never contain duplicate keys, so this mistake has gone unnoticed. The crash could be provoked by malicious or corrupted data.

## Release 15.16

## Release date:

2026-02-12

This release contains a variety of fixes from 15.15. For information about new features in major release 15, see release-15.

## Migration to Version 15.16

A dump/restore is not required for those running 15.X.

However, if you are upgrading from a version earlier than 15.14, see release-15-14.

## Changes

- Guard against unexpected dimensions of `oidvector`/`int2vector` (Tom Lane) §

  These data types are expected to be 1-dimensional arrays containing no nulls, but there are cast pathways that permit violating those expectations. Add checks to some functions that were depending on those expectations without verifying them, and could misbehave in consequence.

  The PostgreSQL Project thanks Altan Birler for reporting this problem. (CVE-2026-2003)

- Harden selectivity estimators against being attached to operators that accept unexpected data types (Tom Lane) § § §

  `contrib/intarray` contained a selectivity estimation function that could be abused for arbitrary code execution, because it did not check that its input was of the expected data type. Third-party extensions should check for similar hazards and add defenses using the technique intarray now uses. Since such extension fixes will take time, we now require superuser privilege to attach a non-built-in selectivity estimator to an operator.

  The PostgreSQL Project thanks Daniel Firer, as part of zeroday.cloud, for reporting this problem. (CVE-2026-2004)

- Fix buffer overrun in `contrib/pgcrypto`'s PGP decryption functions (Michael Paquier) §

  Decrypting a crafted message with an overlength session key caused a buffer overrun, with consequences as bad as arbitrary code execution.

  The PostgreSQL Project thanks Team Xint Code, as part of zeroday.cloud, for reporting this problem. (CVE-2026-2005)

- Fix inadequate validation of multibyte character lengths (Thomas Munro, Noah Misch) § § § § § §

  Assorted bugs allowed an attacker able to issue crafted SQL to overrun string buffers, with consequences as bad as arbitrary code execution. After these fixes, applications may observe invalid byte sequence for encoding errors when string functions process invalid text that has been stored in the database.

  The PostgreSQL Project thanks Paul Gerste and Moritz Sanft, as part of zeroday.cloud, for reporting this problem. (CVE-2026-2006)

- Don't allow CTE references in sub-selects to determine semantic levels of aggregate functions (Tom Lane) §

  This change undoes a change made two minor releases ago, instead throwing an error if a sub-select references a CTE that's below the semantic level that standard SQL rules would assign to the aggregate based on contained column references and aggregates. The attempted fix turned out to cause problems of its own, and it's unclear what to do instead. Since sub-selects within aggregates are disallowed altogether by the SQL standard, treating such cases as errors seems sufficient.

- Fix trigger transition table capture for `MERGE` in CTE queries (Dean Rasheed) §

  When executing a data-modifying CTE query containing both a `MERGE` and another DML operation on a table with statement-level `AFTER` triggers, the transition tables passed to the triggers would not include the rows affected by the `MERGE`, only those affected by the other operation(s).

- Fix failure when all children of a partitioned target table of an update or delete have been pruned (Amit Langote) §

  In such cases, the executor could report could not find junk ctid column errors, even though nothing needs to be done.

- Allow indexscans on partial hash indexes even when the index's predicate implies the truth of the WHERE clause (Tom Lane) §

  Normally we drop a WHERE clause that is implied by the predicate, since it's pointless to test it; it must hold for every index entry. However that can prevent creation of an indexscan plan if the index is one that requires a WHERE clause on the leading index key, as hash indexes do. Don't drop implied clauses when considering such an index.

- Do not emit WAL for unlogged BRIN indexes (Kirill Reshke) §

  One seldom-taken code path incorrectly emitted a WAL record relating to a BRIN index even if the index was marked unlogged. Crash recovery would then fail to replay that record, complaining that the file already exists.

- Prevent truncation of CLOG that is still needed by unread `NOTIFY` messages (Joel Jacobson, Heikki Linnakangas) § § §

  This fix prevents could not access status of transaction errors when a backend is slow to absorb `NOTIFY` messages.

- Escalate errors occurring during `NOTIFY` message processing to FATAL, i.e. close the connection (Heikki Linnakangas) §

  Formerly, if a backend got an error while absorbing a `NOTIFY` message, it would advance past that message, report the error to the client, and move on. That behavior was fraught with problems though. One big concern is that the client has no good way to know that a notification was lost, and certainly no way to know what was in it. Depending on the application logic, missing a notification could cause the application to get stuck waiting, for example. Also, any remaining messages would not get processed until someone sent a new `NOTIFY`.

  Also, if the connection is idle at the time of receiving a `NOTIFY` signal, any ERROR would be escalated to FATAL anyway, due to unrelated concerns. Therefore, we've chosen to make that happen in all cases, for consistency and to provide a clear signal to the application that it might have missed some notifications.

- Fix bug in following update chain when locking a tuple (Jasper Smit) §

  This code path neglected to check the xmin of the first new tuple in the update chain, making it possible to lock an unrelated tuple if the original updater aborted and the space was immediately reclaimed by `VACUUM` and then re-used. That could cause unexpected transaction delays or deadlocks. Errors associated with having identified the wrong tuple have also been observed.

- Fix issues around in-place catalog updates (Noah Misch) § § §

  Send a nontransactional invalidation message for an in-place update, since such an update will survive transaction rollback. Also ensure that the update is WAL-logged before other sessions can see it. These fixes primarily prevent scenarios in which relations' frozen-XID attributes become inconsistent, possibly allowing premature CLOG truncation and subsequent could not access status of transaction errors.

- Fix potential backend process crash at process exit due to trying to release a lock in an already-unmapped shared memory segment (Rahila Syed) §

- Guard against incorrect truncation of the multixact log after a crash (Heikki Linnakangas) §

- Fix possibly mis-encoded result of `pg_stat_get_backend_activity()` (Chao Li) §

  The shared-memory buffer holding a session's activity string can end with an incomplete multibyte character. Readers are supposed to truncate off any such incomplete character, but this function failed to do so.

- Guard against recursive memory context logging (Fujii Masao) §

  A constant flow of signals requesting memory context logging could cause recursive execution of the logging code, which in theory could lead to stack overflow.

- Fix memory context usage when reinitializing a parallel execution context (Jakub Wartak, Jeevan Chalke) §

  This error could result in a crash due to a subsidiary data structure having a shorter lifespan than the parallel context. The problem is not known to be reachable using only core PostgreSQL, but we have reports of trouble in extensions.

- Set next multixid's offset when creating a new multixid, to remove the wait loop that was needed in corner cases (Andrey Borodin) § §

  The previous logic could get stuck waiting for an update that would never occur.

- Avoid rewriting data-modifying CTEs more than once (Bernice Southey, Dean Rasheed) §

  Formerly, when updating an auto-updatable view or a relation with rules, if the original query had any data-modifying CTEs, the rewriter would rewrite those CTEs multiple times due to recursion. This was inefficient and could produce false errors if a CTE included an update of an always-generated column.

- Fail recovery if WAL does not exist back to the redo point indicated by the checkpoint record (Nitin Jadhav) §

  Add an explicit check for this before starting recovery, so that no harm is done and a useful error message is provided. Previously, recovery might crash or corrupt the database in this situation.

- Avoid scribbling on the source query tree during `ALTER PUBLICATION` (Sunil S) §

  This error had the visible effect that an event trigger fired for the query would see only the first `publish` option, even if several had been specified. If such a query were set up as a prepared statement, re-executions would misbehave too.

- Pass connection options specified in `CREATE SUBSCRIPTION ... CONNECTION` to the publisher's walsender (Fujii Masao) §

  Before this fix, the `options` connection option (if any) was ignored, thus for example preventing setting custom server parameter values in the walsender session. It was intended for that to work, and it did work before refactoring in PostgreSQL version 15 broke it, so restore the previous behavior.

- Prevent invalidation of newly created or newly synced replication slots (Zhijie Hou) §

  A race condition with a concurrent checkpoint could allow WAL to be removed that is needed by the replication slot, causing the slot to immediately get marked invalid.

- Fix race condition in computing a replication slot's required xmin (Zhijie Hou) §

  This could lead to the error cannot build an initial slot snapshot as oldest safe xid follows snapshot's xmin.

- During initial synchronization of a logical replication subscription, commit the addition of a pg_replication_origin entry before starting to copy data (Zhijie Hou) §

  Previously, if the copy step failed, the new pg_replication_origin entry would be lost due to transaction rollback. This led to inconsistent state in shared memory.

- Fix possible failure with unexpected data beyond EOF during restart of a streaming replica server (Anthonin Bonnefoy) §

- Fix erroneous tracking of column position when parsing partition range bounds (myzhen) §

  This could, for example, lead to the wrong column name being cited in error messages about casting partition bound values to the column's data type.

- Fix assorted minor errors in error messages (Man Zeng, Tianchen Zhang) § § §

  For example, an error report about mismatched timeline number in a backup manifest showed the starting timeline number where it meant to show the ending timeline number.

- Fix failure to perform function inlining when doing JIT compilation with LLVM version 17 or later (Anthonin Bonnefoy) §

- Adjust our JIT code to work with LLVM 21 (Holger Hoffstätte) §

  The previous coding failed to compile on aarch64 machines.

- Support process title changes on GNU/Hurd (Michael Banck) §

- Make pg_resetwal print the updated value when changing OldestXID (Heikki Linnakangas) §

  It already did that for every other variable it can change.

- Make pg_resetwal allow setting next multixact xid to 0 or next multixact offset to UINT32_MAX (Maxim Orlov) §

  These are valid values, so rejecting them was incorrect. In the worst case, if a pg_upgrade is attempted when exactly at the point of multixact wraparound, the upgrade would fail.

- In `contrib/amcheck`, use the correct snapshot for btree index parent checks (Mihail Nikalayeu) §

  The previous coding caused spurious errors when examining indexes created with `CREATE INDEX CONCURRENTLY`.

- Fix `contrib/amcheck` to handle half-dead btree index pages correctly (Heikki Linnakangas) §

  `amcheck` expected such a page to have a parent downlink, but it does not, leading to a false error report about mismatch between parent key and child high key.

- Fix `contrib/amcheck` to handle incomplete btree root page splits correctly (Heikki Linnakangas) §

  `amcheck` could report a false error about block is not true root.

- Fix edge-case integer overflow in `contrib/intarray`'s selectivity estimator for `@@` (Chao Li) §

  This could cause poor selectivity estimates to be produced for cases involving the maximum integer value.

- Fix multibyte-encoding issue in `contrib/ltree` (Jeff Davis) §

  The previous coding could pass an incomplete multibyte character to `lower()`, probably resulting in incorrect behavior.

- Update time zone data files to tzdata release 2025c (Tom Lane) §

  The only change is in historical data for pre-1976 timestamps in Baja California.

## Release 15.15

## Release date:

2025-11-13

This release contains a variety of fixes from 15.14. For information about new features in major release 15, see release-15.

## Migration to Version 15.15

A dump/restore is not required for those running 15.X.

However, if you are upgrading from a version earlier than 15.14, see release-15-14.

## Changes

- Check for `CREATE` privileges on the schema in `CREATE STATISTICS` (Jelte Fennema-Nio) §

  This omission allowed table owners to create statistics in any schema, potentially leading to unexpected naming conflicts.

  The PostgreSQL Project thanks Jelte Fennema-Nio for reporting this problem. (CVE-2025-12817)

- Avoid integer overflow in allocation-size calculations within libpq (Jacob Champion) §

  Several places in libpq were not sufficiently careful about computing the required size of a memory allocation. Sufficiently large inputs could cause integer overflow, resulting in an undersized buffer, which would then lead to writing past the end of the buffer.

  The PostgreSQL Project thanks Aleksey Solovev of Positive Technologies for reporting this problem. (CVE-2025-12818)

- Further fix processing of character classes within `SIMILAR TO` regular expressions (Laurenz Albe) §

  The previous fix for translating `SIMILAR TO` pattern matching expressions to POSIX-style regular expressions broke a corner case that formerly worked: if there is an escape character right after the opening bracket and then a closing bracket right after the escape sequence (for example `[\w]`), the closing bracket was no longer seen as terminating the character class.

- Fix parsing of aggregate functions whose arguments contain a sub-select with a `FROM` reference to a CTE outside the aggregate function (Tom Lane) §

  Such a CTE reference must act like a outer-level column reference when determining the aggregate's semantic level; but it was not being accounted for, leading to obscure planner or executor errors.

- Fix no relation entry for relid errors in corner cases while estimating SubPlan costs (Richard Guo) §

- Avoid unlikely use-after-free in planner's expansion of partitioned tables (Bernd Reiß) §

  There was a hazard only when the last live partition was concurrently dropped.

- Remove faulty assertion in btree index cleanup (Peter Geoghegan) §

- Fix possible infinite loop in GIN index scans with multiple scan conditions (Tom Lane) §

  GIN can handle scan conditions that can reject non-matching entries but are not useful for searching for relevant entries, for example a `tsquery` clause like `!term`. But such a condition must not be first in the array of scan conditions. The code failed to ensure that in all cases, with the result that a query having a mix of such conditions with normal conditions might work or not depending on the order in which the conditions were given in the query.

- Ensure that GIN index scans can be canceled (Tom Lane) §

  Some code paths were capable of running for a long time without checking for interrupts.

- Ensure that BRIN autosummarization provides a snapshot for index expressions that need one (Álvaro Herrera) § §

  Previously, autosummarization would fail for such indexes, and then leave placeholder index tuples behind, causing the index to bloat over time.

- Fix integer-overflow hazard in BRIN index scans when the table contains close to 232 pages (Sunil S) §

  This oversight could result in an infinite loop or scanning of unneeded table pages.

- Fix incorrect zero-extension of stored values in JIT-generated tuple deforming code (David Rowley) §

  When not using JIT, the equivalent code does sign-extension not zero-extension, leading to a different Datum representation of small integer data types. This inconsistency was masked in most cases, but it is known to lead to could not find memoization table entry errors when using Memoize plan nodes, and there might be other symptoms.

- Fix incorrect logic for caching result-relation information for triggers (David Rowley, Amit Langote) §

  In cases where partitions' column sets aren't physically identical to their parent partitioned tables' column sets, this oversight could lead to crashes.

- Add missing EvalPlanQual rechecks for TID Scan and TID Range Scan plan nodes (Sophie Alpert, David Rowley) § §

  This omission led to possibly not rechecking a condition on ctid during concurrent-update situations, causing the update's behavior to vary depending on which plan type had been selected.

- Fix EvalPlanQual handling of foreign or custom joins that do not have an alternative local-join plan prepared for EPQ (Masahiko Sawada, Etsuro Fujita) §

  In such cases the foreign or custom access method should be invoked normally, but that did not happen, typically leading to a crash.

- Avoid duplicating hash partition constraints during `DETACH CONCURRENTLY` (Haiyang Li) §

  `ALTER TABLE DETACH PARTITION CONCURRENTLY` was written to add a copy of the partitioning constraint to the now-detached partition. This was misguided, partially because non-concurrent `DETACH` doesn't do that, but mostly because in the case of hash partitioning the constraint expression contains references to the parent table's OID. That causes problems during dump/restore, or if the parent table is dropped after `DETACH`. In v19 and later, we'll no longer create any such copied constraints at all. In released branches, to minimize the risk of unforeseen consequences, only skip adding a copied constraint if it is for hash partitioning.

- Disallow generated columns in partition keys (Jian He, Ashutosh Bapat) §

  This was already not allowed, but the check missed some cases, such as where the column reference is implicit in a whole-row reference.

- Disallow generated columns in `COPY ... FROM ... WHERE` clauses (Peter Eisentraut, Jian He) §

  Previously, incorrect behavior or an obscure error message resulted from attempting to reference such a column, since generated columns have not yet been computed at the point where `WHERE` filtering is done.

- Fix visibility checking for statistics objects in `pg_temp` (Noah Misch) §

  A statistics object located in a temporary schema cannot be named without schema qualification, but `pg_statistics_obj_is_visible()` missed that memo and could return true regardless. In turn, functions such as `pg_describe_object()` could fail to schema-qualify the object's name as expected.

- Fix `pg_event_trigger_dropped_objects()`'s reporting of temporary status (Antoine Violin, Tom Lane) § §

  If a dropped column default, trigger, or RLS policy belongs to a temporary table, report it with `is_temporary` true.

- Fix memory leakage in hashed subplans (Haiyang Li) §

  Any memory consumed by the hash functions used for hashing tuples constituted a query-lifespan memory leak. One way that could happen is if the values being hashed require de-toasting.

- Fix minor memory leak during WAL replay of database creation (Nathan Bossart) §

- Fix corruption of the shared statistics table after out-of-memory failures (Mikhail Kot) §

  Previously, an out-of-memory failure partway through creating a new hash table entry left a broken entry behind, potentially causing errors in other sessions later.

- Fix concurrent update issue in `MERGE` (Yugo Nagata) §

  When executing a `MERGE UPDATE` action, if there is more than one concurrent update of the target row, the lock-and-retry code would sometimes incorrectly identify the latest version of the target tuple, leading to incorrect results.

- Add missing replica identity checks in `MERGE` and `INSERT ... ON CONFLICT DO UPDATE` (Zhijie Hou) § § §

  If `MERGE` may require update or delete actions, and the target table publishes updates or deletes, insist that it have a `REPLICA IDENTITY` defined. Failing to require this can silently break replication. Likewise, `INSERT` with an `UPDATE` option must require `REPLICA IDENTITY` if the target table publishes either inserts or updates.

- Avoid deadlock during `DROP SUBSCRIPTION` when publisher is on the same server as subscriber (Dilip Kumar) §

- Fix incorrect reporting of replication lag in pg_stat_replication view (Fujii Masao) §

  If any standby server's replay LSN stopped advancing, the write_lag and flush_lag columns would eventually stop updating.

- Avoid duplicative log messages about invalid `primary_slot_name` settings (Fujii Masao) §

- Remove the unfinished slot state file after failing to write a replication slot's state to disk (Michael Paquier) §

  Previously, a failure such as out-of-disk-space resulted in leaving a temporary `state.tmp` file behind. That's problematic because it would block all subsequent attempts to write the state, requiring manual intervention to clean up.

- Avoid unwanted WAL receiver shutdown when switching from streaming to archive WAL source (Xuneng Zhou) §

  During a timeline change, a standby server's WAL receiver should remain alive, waiting for a new WAL streaming start point. Instead it was repeatedly shutting down and immediately getting restarted, which could confuse status monitoring code.

- Avoid failures in logical replication due to chance collisions of file numbers between regular and temporary tables (Vignesh C) §

  This low-probability problem manifested as transient errors like unexpected duplicate for tablespace `X`, relfilenode `Y`. `contrib/autoprewarm` was also affected. A side-effect of the fix is that the SQL function `pg_filenode_relation()` will now ignore temporary tables.

- Fix use-after-free issue in the relation synchronization cache maintained by the pgoutput logical decoding plugin (Vignesh C, Masahiko Sawada) §

  An error during logical decoding could result in crashes in subsequent logical decoding attempts in the same session. The case is only reachable when pgoutput is invoked via SQL functions.

- Avoid assertion failure when trying to release a replication slot in single-user mode (Hayato Kuroda) §

- Fix incorrect printing of messages about failures in checking whether the user has Windows administrator privilege (Bryan Green) §

  This code would have crashed or at least printed garbage. No such cases have been reported though, indicating that failure of these system calls is extremely rare.

- Avoid startup failure on macOS and BSD platforms when there is a collision with a pre-existing semaphore set (Tom Lane) §

  If the pre-existing set has fewer semaphores than we asked for, these platforms return `EINVAL` not `EEXIST` as our code expected, resulting in failure to start the database.

- Fix false memory-context-checking warnings in debug builds on 64-bit Windows (David Rowley) §

- Correctly handle `GROUP BY DISTINCT` in PL/pgSQL assignment statements (Tom Lane) §

  The parser failed to record the `DISTINCT` option in this context, so that the command would act as if it were plain `GROUP BY`.

- Avoid leaking memory when handling a SQL error within PL/Python (Tom Lane) §

  This fixes a session-lifespan memory leak introduced in our previous minor releases.

- Fix libpq's trace output of characters with the high bit set (Ran Benita) §

  On platforms where `char` is considered signed, the output included unsightly `\xffffff` decoration.

- Fix libpq's handling of socket-related errors on Windows within its GSSAPI logic (Ning Wu, Tom Lane) §

  The code for encrypting/decrypting transmitted data using GSSAPI did not correctly recognize error conditions on the connection socket, since Windows reports those differently than other platforms. This led to failure to make such connections on Windows.

- In pg_dump, dump security labels on subscriptions and event triggers (Jian He, Fujii Masao) §

  Labels on these types of objects were previously missed.

- Fix pg_dump's sorting of default ACLs and foreign key constraints (Kirill Reshke, Álvaro Herrera) § § §

  Ensure consistent ordering of these database object types, as was already done for other object types.

- In pg_dump, label comments for separately-dumped domain constraints with the proper dependency (Noah Misch) §

  This error could lead to parallel pg_restore attempting to create the comment before the constraint itself has been restored.

- In pg_restore, skip comments and security labels for publications and subscriptions that are not being restored (Jian He, Fujii Masao) § §

  Do not emit `COMMENT` or `SECURITY LABEL` commands for these objects when `--no-publications` or `--no-subscriptions` is specified.

- Fix assorted errors in the data compression logic in pg_dump and pg_restore (Daniel Gustafsson, Tom Lane) §

  Error checking was missing or incorrect in several places, and there were also portability issues that would manifest on big-endian hardware. These problems had been missed because this code is only used to read compressed TOC files within directory-format dumps. pg_dump never produces such a dump; the case can be reached only by manually compressing the TOC file after the fact, which is a supported thing to do but very uncommon.

- Fix pgbench to error out cleanly if a `COPY` operation is started (Anthonin Bonnefoy) §

  pgbench doesn't intend to support this case, but previously it went into an infinite loop.

- Fix pgbench's reporting of multiple errors (Yugo Nagata) §

  In cases where two successive `PQgetResult` calls both fail, pgbench might report the wrong error message.

- In pgbench, fix faulty assertion about errors in pipeline mode (Yugo Nagata) §

- Ensure that `contrib/pg_buffercache` functions can be canceled (Satyanarayana Narlapuram, Yuhang Qiu) §

  Some code paths were capable of running for a long time without checking for interrupts.

- Fix `contrib/pg_prewarm`'s privilege checks for indexes (Ayush Vatsa, Nathan Bossart) §

  `pg_prewarm()` requires `SELECT` privilege on relations to be prewarmed. However, since indexes have no SQL privileges of their own, this resulted in non-superusers being unable to prewarm indexes. Instead, check for `SELECT` privilege on the index's table.

- Make `contrib/pgstattuple` more robust about empty or invalid index pages (Nitin Motiani) §

  Count all-zero pages as free space, and ignore pages that are invalid according to a check of the page's special-space size. The code for btree indexes already counted all-zero pages as free, but the hash and gist code would error out, which has been found to be much less user-friendly. Similarly, make all three cases agree on ignoring corrupted pages rather than throwing errors.

- Harden our read and write barrier macros to satisfy Clang (Thomas Munro) §

  We supposed that `__atomic_thread_fence()` is a sufficient barrier to prevent the C compiler from re-ordering memory accesses around it, but it appears that that's not true for Clang, allowing it to generate incorrect code for at least RISC-V, MIPS, and LoongArch machines. Add explicit compiler barriers to fix that.

- Fix building with LLVM version 21 and later (Holger Hoffstätte) §

- Fix PGXS build infrastructure to support building NLS `po` files for extensions (Ryo Matsumura) §

## Release 15.14

## Release date:

2025-08-14

This release contains a variety of fixes from 15.13. For information about new features in major release 15, see release-15.

## Migration to Version 15.14

A dump/restore is not required for those running 15.X.

However, if you have any BRIN `numeric_minmax_multi_ops` indexes, it is advisable to reindex them after updating. See the fourth changelog entry below.

Also, if you are upgrading from a version earlier than 15.13, see release-15-13.

## Changes

- Tighten security checks in planner estimation functions (Dean Rasheed) §

  The fix for CVE-2017-7484, plus followup fixes, intended to prevent leaky functions from being applied to statistics data for columns that the calling user does not have permission to read. Two gaps in that protection have been found. One gap applies to partitioning and inheritance hierarchies where RLS policies on the tables should restrict access to statistics data, but did not.

  The other gap applies to cases where the query accesses a table via a view, and the view owner has permissions to read the underlying table but the calling user does not have permissions on the view. The view owner's permissions satisfied the security checks, and the leaky function would get applied to the underlying table's statistics before we check the calling user's permissions on the view. This has been fixed by making security checks on views occur at the start of planning. That might cause permissions failures to occur earlier than before.

  The PostgreSQL Project thanks Dean Rasheed for reporting this problem. (CVE-2025-8713)

- Prevent pg_dump scripts from being used to attack the user running the restore (Nathan Bossart) §

  Since dump/restore operations typically involve running SQL commands as superuser, the target database installation must trust the source server. However, it does not follow that the operating system user who executes psql to perform the restore should have to trust the source server. The risk here is that an attacker who has gained superuser-level control over the source server might be able to cause it to emit text that would be interpreted as psql meta-commands. That would provide shell-level access to the restoring user's own account, independently of access to the target database.

  To provide a positive guarantee that this can't happen, extend psql with a `\restrict` command that prevents execution of further meta-commands, and teach pg_dump to issue that before any data coming from the source server.

  The PostgreSQL Project thanks Martin Rakhmanov, Matthieu Denais, and RyotaK for reporting this problem. (CVE-2025-8714)

- Convert newlines to spaces in names included in comments in pg_dump output (Noah Misch) §

  Object names containing newlines offered the ability to inject arbitrary SQL commands into the output script. (Without the preceding fix, injection of psql meta-commands would also be possible this way.) CVE-2012-0868 fixed this class of problem at the time, but later work reintroduced several cases.

  The PostgreSQL Project thanks Noah Misch for reporting this problem. (CVE-2025-8715)

- Fix incorrect distance calculation in BRIN `numeric_minmax_multi_ops` support function (Peter Eisentraut, Tom Lane) §

  The results were sometimes wrong on 64-bit platforms, and wildly wrong on 32-bit platforms. This did not produce obvious failures because the logic is only used to choose how to merge values into ranges; at worst the index would become inefficient and bloated. Nonetheless it's recommended to reindex any BRIN indexes that use the `numeric_minmax_multi_ops` operator class.

- Avoid regression in the size of XML input that we will accept (Michael Paquier, Erik Wienhold) § §

  Our workaround for a bug in early 2.13.x releases of libxml2 made use of a code path that rejects text chunks exceeding 10MB, whereas the previous coding did not. Those early releases are presumably extinct in the wild by now, so revert to the previous coding.

- Fix `MERGE` into a plain-inheritance parent table (Dean Rasheed) §

  Insertions into such a target table could crash or produce incorrect query results due to failing to handle `WITH CHECK OPTION` and `RETURNING` actions.

- Allow tables with statement-level triggers to become partitions or inheritance children (Etsuro Fujita) §

  We do not allow partitions or inheritance child tables to have row-level triggers with transition tables, because an operation on the whole inheritance tree would need to maintain a separate transition table for each such child table. But that problem does not apply for statement-level triggers, because only the parent's statement-level triggers will be fired. The code that checks whether an existing table can become a partition or inheritance child nonetheless rejected both kinds of trigger.

- Disallow collecting transition tuples from child foreign tables (Etsuro Fujita) §

  We do not support triggers with transition tables on foreign tables. However, the case of a partition or inheritance child that is a foreign table was overlooked. If the parent has such a trigger, incorrect transition tuples were collected from the foreign child. Instead throw an error, reporting that the case is not supported.

- Allow resetting unknown custom parameters with reserved prefixes (Nathan Bossart) §

  Previously, if a parameter setting had been stored using `ALTER DATABASE/ROLE/SYSTEM`, the stored setting could not be removed if the parameter was unknown but had a reserved prefix. This case could arise if an extension used to have a parameter, but that parameter had been removed in an upgrade.

- Fix a potential deadlock during `ALTER SUBSCRIPTION ... DROP PUBLICATION` (Ajin Cherian) §

  Ensure that server processes acquire catalog locks in a consistent order during replication origin drops.

- Shorten the race condition window for creating indexes with conflicting names (Tom Lane) §

  When choosing an auto-generated name for an index, avoid conflicting with not-yet-committed pg_class rows as well as fully-valid ones. This avoids possibly choosing the same name as some concurrent `CREATE INDEX` did, when that command is still in process of filling its index, or is done but is part of a not-yet-committed transaction. There's still a window for trouble, but it's only as long as the time needed to validate a new index's parameters and insert its pg_class row.

- Prevent usage of incorrect `VACUUM` options in some cases where multiple tables are vacuumed in a single command (Nathan Bossart, Michael Paquier) §

  The `TRUNCATE` and `INDEX_CLEANUP` options of one table could be applied to others.

- Fix processing of character classes within `SIMILAR TO` regular expressions (Laurenz Albe) § §

  The code that translates `SIMILAR TO` pattern matching expressions to POSIX-style regular expressions did not consider that square brackets can be nested. For example, in a pattern like `[[:alpha:]%_]`, the code treated the `%` and `_` characters as metacharacters when they should be literals.

- When deparsing queries, always add parentheses around the expression in `FETCH FIRST `expression` ROWS WITH TIES` clauses (Heikki Linnakangas) §

  This avoids some cases where the deparsed result wasn't syntactically valid.

- Limit the checkpointer process's fsync request queue size (Alexander Korotkov, Xuneng Zhou) § §

  With very large `shared_buffers` settings, it was possible for the checkpointer to attempt to allocate more than 1GB for fsync requests, leading to failure and an infinite loop. Clamp the queue size to prevent this scenario.

- Avoid infinite wait in logical decoding when reading a partially-written WAL record (Vignesh C) §

  If the server crashes after writing the first part of a WAL record that would span multiple pages, subsequent logical decoding of the WAL stream would wait for data to arrive on the next WAL page. That might never happen if the server is now idle.

- Fix inconsistent quoting of role names in ACL strings (Tom Lane) §

  The previous quoting rule was locale-sensitive, which could lead to portability problems when transferring `aclitem` values across installations. (pg_dump does not do that, but other tools might.) To ensure consistency, always quote non-ASCII characters in `aclitem` output; but to preserve backward compatibility, never require that they be quoted during `aclitem` input.

- Reject equal signs (`=`) in the names of relation options and foreign-data options (Tom Lane) §

  There's no evident use-case for option names like this, and allowing them creates ambiguity in the stored representation.

- Fix potentially-incorrect decompression of LZ4-compressed archive data (Mikhail Gribkov) §

  This error seems to manifest only with not-very-compressible input data, which may explain why it escaped detection.

- Avoid a rare scenario where a btree index scan could mark the wrong index entries as dead (Peter Geoghegan) §

- Avoid re-distributing cache invalidation messages from other transactions during logical replication (vignesh C) §

  Our previous round of minor releases included a bug fix to ensure that replication receiver processes would respond to cross-process cache invalidation messages, preventing them from using stale catalog data while performing replication updates. However, the fix unintentionally made them also redistribute those messages again, leading to an exponential increase in the number of invalidation messages, which would often end in a memory allocation failure. Fix by not redistributing received messages.

- Avoid premature removal of old WAL during checkpoints (Vitaly Davydov) §

  If a replication slot's restart point is advanced while a checkpoint is in progress, no-longer-needed WAL segments could get removed too soon, leading to recovery failure if the database crashes immediately afterwards. Fix by keeping them for one additional checkpoint cycle.

- Never move a replication slot's confirmed-flush position backwards (Shveta Malik) §

  In some cases a replication client could acknowledge an LSN that's past what it has stored persistently, and then perhaps send an older LSN after a restart. We consider this not-a-bug so long as the client did not have anything it needed to do for the WAL between the two points. However, we should not re-send that WAL for fear of data duplication, so make sure we always believe the latest confirmed LSN for a given slot.

- Allow waiting for a transaction on a standby server to be interrupted (Kevin K Biju) §

  Creation of a replication slot on a standby server may require waiting for some active transaction(s) to finish on the primary and then be replayed on the standby. Since that could be an indefinite wait, it's desirable to allow the operation to be cancelled, but there was no check for query cancel in the loop.

- Fix per-relation memory leakage in autovacuum (Tom Lane) §

- Fix some places that might try to fetch toasted fields of system catalogs without any snapshot (Nathan Bossart) §

  This could result in an assertion failure or cannot fetch toast data without an active snapshot error.

- Avoid assertion failure during cross-table constraint updates (Tom Lane, Jian He) § §

- Remove faulty assertion that a command tag must have been determined by the end of `PortalRunMulti()` (Álvaro Herrera) §

  This failed in edge cases such as an empty prepared statement.

- Fix assertion failure in `XMLTABLE` parsing (Richard Guo) §

- Restore the ability to run PL/pgSQL expressions in parallel (Dipesh Dhameliya) §

  PL/pgSQL's notion of an expression is very broad, encompassing any SQL `SELECT` query that returns a single column and no more than one row. So there are cases, for example evaluation of an aggregate function, where the query involves significant work and it'd be useful to run it with parallel workers. This used to be possible, but a previous bug fix unintentionally disabled it.

- Fix edge-case resource leaks in PL/Python error reporting (Tom Lane) § §

  An out-of-memory failure while reporting an error from Python could result in failure to drop reference counts on Python objects, leading to session-lifespan memory leakage.

- Fix libpq's `PQport()` function to never return NULL unless the passed connection is NULL (Daniele Varrazzo) §

  This is the documented behavior, but recent libpq versions would return NULL in some cases where the user had not provided a port specification. Revert to our historical behavior of returning an empty string in such cases. (v18 and later will return the compiled-in default port number, typically `"5432"`, instead.)

- Avoid failure when GSSAPI authentication requires packets larger than 16kB (Jacob Champion, Tom Lane) §

  Larger authentication packets are needed for Active Directory users who belong to many AD groups. This limitation manifested in connection failures with unintelligible error messages, typically GSSAPI context establishment error: The routine must be called again to complete its function: Unknown error.

- Fix timing-dependent failures in SSL and GSSAPI data transmission (Tom Lane) §

  When using SSL or GSSAPI encryption in non-blocking mode, libpq sometimes failed with SSL error: bad length or GSSAPI caller failed to retransmit all data needing to be retried.

- Avoid null-pointer dereference during connection lookup in ecpg applications (Aleksander Alekseev) §

  The case could occur only if the application has some connections that are named and some that are not.

- Improve psql's tab completion for `COPY` and `\copy` options (Atsushi Torikoshi) §

  The same completions were offered for both `COPY FROM` and `COPY TO`, although some options are only valid for one case or the other. Distinguish these cases to provide more accurate suggestions.

- Avoid assertion failure in pgbench when multiple pipeline sync messages are received (Fujii Masao) §

- Ensure that pg_dump dumps comments on domain constraints in a valid order (Jian He) §

  In some cases the comment command could appear before creation of the constraint.

- Ensure stable sort ordering in pg_dump for all types of database objects (Noah Misch, Andreas Karlsson) § § §

  pg_dump sorts objects by their logical names before performing dependency-driven reordering. This sort did not account for the full unique key identifying certain object types such as rules and constraints, and thus it could produce dissimilar sort orders for logically-identical databases. That made it difficult to compare databases by diff'ing pg_dump output, so improve the logic to ensure stable sort ordering in all cases.

- In pg_upgrade, check for inconsistent inherited not-null constraints (Ali Akbar) § § § § § §

  PostgreSQL versions before 18 allow an inherited column not-null constraint to be dropped. However, this results in a schema that cannot be restored, leading to failure in pg_upgrade. Detect such cases during pg_upgrade's preflight checks to allow users to fix them before initiating the upgrade.

- Avoid assertion failure if `track_commit_timestamp` is enabled during initdb (Hayato Kuroda, Andy Fan) §

- Fix pg_waldump to show information about dropped statistics in `PREPARE TRANSACTION` WAL records (Daniil Davydov) §

- Avoid possible leak of the open connection during `contrib/dblink` connection establishment (Tom Lane) §

  In the rare scenario where we hit out-of-memory while inserting the new connection object into dblink's hashtable, the open connection would be leaked until end of session, leaving an idle session sitting on the remote server.

- Make `contrib/pg_prewarm` cope with very large `shared_buffers` settings (Daria Shanina) §

  Autoprewarm failed with a memory allocation error if `shared_buffers` was larger than about 50 million buffers (400GB).

- In `contrib/pg_stat_statements`, avoid leaving gaps in the set of parameter numbers used in a normalized query (Sami Imseih) §

- Fix memory leakage in `contrib/postgres_fdw`'s DirectModify methods (Tom Lane) §

  The PGresult holding the results of the remote modify command would be leaked for the rest of the session if the query fails between invocations of the DirectModify methods, which could happen when there's `RETURNING` data to process.

- Ensure that directories listed in configure's `--with-includes` and `--with-libraries` options are searched before system-supplied directories (Tom Lane) §

  A common reason for using these options is to allow a user-built version of some library to override the system-supplied version. However, that failed to work in some environments because of careless ordering of switches in the commands issued by the makefiles.

- Fix configure's checks for `__cpuid()` and `__cpuidex()` (Lukas Fittl, Michael Paquier) §

  configure failed to detect these Windows-specific functions, so that they would not be used, leading to slower-than-necessary CRC computations since the availability of hardware instructions could not be verified. The practical impact of this error was limited, because production builds for Windows typically do not use the Autoconf toolchain.

- Fix build failure with `--with-pam` option on Solaris-based platforms (Tom Lane) §

  Solaris is inconsistent with other Unix platforms about the API for PAM authentication. This manifested as an inconsistent pointer compiler warning, which we never did anything about. But as of GCC 14 it's an error not warning by default, so fix it.

- Make our code portable to GNU Hurd (Michael Banck, Christoph Berg, Samuel Thibault) §

  Fix assumptions about `IOV_MAX` and `O_RDONLY` that don't hold on Hurd.

- Make our usage of `memset_s()` conform strictly to the C11 standard (Tom Lane) §

  This avoids compile failures on some platforms.

- Prevent uninitialized-value compiler warnings in JSONB comparison code (Tom Lane) §

- Avoid deprecation warnings when building with libxml2 2.14 and later (Michael Paquier) §

- Avoid problems when compiling `pg_locale.h` under C++ (John Naylor) §

  PostgreSQL header files generally need to be wrapped in `extern "C" { ... }` in order to be included in extensions written in C++. This failed for `pg_locale.h` because of its use of libicu headers, but we can work around that by suppressing C++-only declarations in those headers. C++ extensions that want to use libicu's C++ APIs can do so by including the libicu headers ahead of `pg_locale.h`.

## Release 15.13

## Release date:

2025-05-08

This release contains a variety of fixes from 15.12. For information about new features in major release 15, see release-15.

## Migration to Version 15.13

A dump/restore is not required for those running 15.X.

However, if you have any self-referential foreign key constraints on partitioned tables, it may be necessary to recreate those constraints to ensure that they are being enforced correctly. See the second changelog entry below.

Also, if you have any BRIN bloom indexes, it may be advisable to reindex them after updating. See the third changelog entry below.

Also, if you are upgrading from a version earlier than 15.9, see release-15-9.

## Changes

- Avoid one-byte buffer overread when examining invalidly-encoded strings that are claimed to be in GB18030 encoding (Noah Misch, Andres Freund) § §

  While unlikely, a SIGSEGV crash could occur if an incomplete multibyte character appeared at the end of memory. This was possible both in the server and in libpq-using applications. (CVE-2025-4207)

- Handle self-referential foreign keys on partitioned tables correctly (Álvaro Herrera) §

  Creating or attaching partitions failed to make the required catalog entries for a foreign-key constraint, if the table referenced by the constraint was the same partitioned table. This resulted in failure to enforce the constraint fully.

  To fix this, you should drop and recreate any self-referential foreign keys on partitioned tables, if partitions have been created or attached since the constraint was created. Bear in mind that violating rows might already be present, in which case recreating the constraint will fail, and you'll need to fix up those rows before trying again.

- Avoid data loss when merging compressed BRIN summaries in `brin_bloom_union()` (Tomas Vondra) §

  The code failed to account for decompression results not being identical to the input objects, which would result in failure to add some of the data to the merged summary, leading to missed rows in index searches.

  This mistake was present back to v14 where BRIN bloom indexes were introduced, but this code path was only rarely reached then. It's substantially more likely to be hit in v17 because parallel index builds now use the code.

- Fix unexpected attribute has wrong type errors in `UPDATE`, `DELETE`, and `MERGE` queries that use whole-row table references to views or functions in `FROM` (Tom Lane) § § §

- Fix `MERGE` into a partitioned table with `DO NOTHING` actions (Tender Wang) §

  Some cases failed with unknown action in MERGE WHEN clause errors.

- Prevent failure in `INSERT` commands when the table has a `GENERATED` column of a domain data type and the domain's constraints disallow null values (Jian He) §

  Constraint failure was reported even if the generation expression produced a perfectly okay result.

- Correctly process references to outer CTE names that appear within a `WITH` clause attached to an `INSERT`/`UPDATE`/`DELETE`/`MERGE` command that's inside `WITH` (Tom Lane) §

  The parser failed to detect disallowed recursion cases, nor did it account for such references when sorting CTEs into a usable order.

- Fix `ARRAY(`subquery`)` and `ARRAY[`expression, ...`]` constructs to produce sane results when the input is of type `int2vector` or `oidvector` (Tom Lane) §

  This patch restores the behavior that existed before PostgreSQL 9.5: the result is of type `int2vector[]` or `oidvector[]`.

- Fix possible erroneous reports of invalid affixes while parsing Ispell dictionaries (Jacob Brazeal) §

- Fix `ALTER TABLE ADD COLUMN` to correctly handle the case of a domain type that has a default (Jian He, Tom Lane, Tender Wang) § §

  If a domain type has a default, adding a column of that type (without any explicit `DEFAULT` clause) failed to install the domain's default value in existing rows, instead leaving the new column null.

- Repair misbehavior when there are duplicate column names in a foreign key constraint's `ON DELETE SET DEFAULT` or `SET NULL` action (Tom Lane) §

- Improve the error message for disallowed attempts to alter the properties of a foreign key constraint (Álvaro Herrera) §

- Avoid error when resetting the relhassubclass flag of a temporary table that's marked `ON COMMIT DELETE ROWS` (Noah Misch) §

- Fix planner's failure to identify more than one hashable ScalarArrayOpExpr subexpression within a top-level expression (David Geier) §

  This resulted in unnecessarily-inefficient execution of any additional subexpressions that could have been processed with a hash table (that is, `IN`, `NOT IN`, or `= ANY` clauses with all-constant right-hand sides).

- Disable skip fetch optimization in bitmap heap scan (Matthias van de Meent) §

  It turns out that this optimization can result in returning dead tuples when a concurrent vacuum marks a page all-visible.

- Fix performance issues in GIN index search startup when there are many search keys (Tom Lane, Vinod Sridharan) § §

  An indexable clause with many keys (for example, `jsonbcol ?| array[...]` with tens of thousands of array elements) took O(N2) time to start up, and was uncancelable for that interval too.

- Detect missing support procedures in a BRIN index operator class, and report an error instead of crashing (Álvaro Herrera) §

- Respond to interrupts (such as query cancel) while waiting for asynchronous subplans of an Append plan node (Heikki Linnakangas) §

  Previously, nothing would happen until one of the subplans becomes ready.

- Fix race condition in handling of `synchronous_standby_names` immediately after startup (Melnikov Maksim, Michael Paquier) §

  For a short period after system startup, backends might fail to wait for synchronous commit even though `synchronous_standby_names` is enabled.

- Fix `pg_strtof()` to not crash with null endptr (Alexander Lakhin, Tom Lane) §

- Avoid crash when a Snowball stemmer encounters an out-of-memory condition (Maksim Korotkov) §

- Prevent over-advancement of catalog xmin in fast forward mode of logical decoding (Zhijie Hou) §

  This mistake could allow deleted catalog entries to be vacuumed away even though they were still potentially needed by the WAL-reading process.

- Avoid data loss when DDL operations that don't take a strong lock affect tables that are being logically replicated (Shlok Kyal, Hayato Kuroda) § §

  The catalog changes caused by the DDL command were not reflected into WAL-decoding processes, allowing them to decode subsequent changes using stale catalog data, probably resulting in data corruption.

- Avoid duplicate snapshot creation in logical replication index lookups (Heikki Linnakangas) § §

- Fix wrong checkpoint details in error message about incorrect recovery timeline choice (David Steele) §

  If the requested recovery timeline is not reachable, the reported checkpoint and timeline should be the values read from the backup_label, if there is one. This message previously reported values from the control file, which is correct when recovering from the control file without a backup_label, but not when there is a backup_label.

- Fix assertion failure in snapshot building (Masahiko Sawada) §

- Remove incorrect assertion in `pgstat_report_stat()` (Michael Paquier) §

- Fix overly-strict assertion in `gistFindCorrectParent()` (Heikki Linnakangas) §

- Fix rare assertion failure in standby servers when the primary is restarted (Heikki Linnakangas) §

- In PL/pgSQL, avoid unexpected plan node type error when a scrollable cursor is defined on a simple `SELECT `expression`` query (Andrei Lepikhov) §

- Don't try to drop individual index partitions in pg_dump's `--clean` mode (Jian He) §

  The server rejects such `DROP` commands. That has no real consequences, since the partitions will go away anyway in the subsequent `DROP`s of either their parent tables or their partitioned index. However, the error reported for the attempted drop causes problems when restoring in `--single-transaction` mode.

- In pg_dumpall, avoid emitting invalid role `GRANT` commands if pg_auth_members contains invalid role OIDs (Tom Lane) §

  Instead, print a warning and skip the entry. This copes better with catalog corruption that has been seen to occur in back branches as a result of race conditions between `GRANT` and `DROP ROLE`.

- In pg_amcheck and pg_upgrade, use the correct function to free allocations made by libpq (Michael Paquier, Ranier Vilela) §

  These oversights could result in crashes in certain Windows build configurations, such as a debug build of libpq used by a non-debug build of the calling application.

- Allow `contrib/dblink` queries to be interrupted by query cancel (Noah Misch) § §

  This change back-patches a v17-era fix. It prevents possible hangs in `CREATE DATABASE` and `DROP DATABASE` due to failure to detect deadlocks.

- Avoid crashing with corrupt input data in `contrib/pageinspect`'s `heap_page_items()` (Dmitry Kovalenko) §

- Prevent assertion failure in `contrib/pg_freespacemap`'s `pg_freespacemap()` (Tender Wang) §

  Applying `pg_freespacemap()` to a relation lacking storage (such as a view) caused an assertion failure, although there was no ill effect in non-assert builds. Add an error check to reject that case.

- Fix build failure on macOS 15.4 (Tom Lane, Peter Eisentraut) §

  This macOS update broke our configuration probe for `strchrnul()`.

- Update time zone data files to tzdata release 2025b for DST law changes in Chile, plus historical corrections for Iran (Tom Lane) §

  There is a new time zone America/Coyhaique for Chile's Aysén Region, to account for it changing to UTC-03 year-round and thus diverging from America/Santiago.

## Release 15.12

## Release date:

2025-02-20

This release contains a few fixes from 15.11. For information about new features in major release 15, see release-15.

## Migration to Version 15.12

A dump/restore is not required for those running 15.X.

However, if you are upgrading from a version earlier than 15.9, see release-15-9.

## Changes

- Improve behavior of libpq's quoting functions (Andres Freund, Tom Lane) § § §

  The changes made for CVE-2025-1094 had one serious oversight: `PQescapeLiteral()` and `PQescapeIdentifier()` failed to honor their string length parameter, instead always reading to the input string's trailing null. This resulted in including unwanted text in the output, if the caller intended to truncate the string via the length parameter. With very bad luck it could cause a crash due to reading off the end of memory.

  In addition, modify all these quoting functions so that when invalid encoding is detected, an invalid sequence is substituted for just the first byte of the presumed character, not all of it. This reduces the risk of problems if a calling application performs additional processing on the quoted string.

## Release 15.11

## Release date:

2025-02-13

This release contains a variety of fixes from 15.10. For information about new features in major release 15, see release-15.

## Migration to Version 15.11

A dump/restore is not required for those running 15.X.

However, if you are upgrading from a version earlier than 15.9, see release-15-9.

## Changes

- Harden `PQescapeString` and allied functions against invalidly-encoded input strings (Andres Freund, Noah Misch) § § § § § §

  Data-quoting functions supplied by libpq now fully check the encoding validity of their input. If invalid characters are detected, they report an error if possible. For the ones that lack an error return convention, the output string is adjusted to ensure that the server will report invalid encoding and no intervening processing will be fooled by bytes that might happen to match single quote, backslash, etc.

  The purpose of this change is to guard against SQL-injection attacks that are possible if one of these functions is used to quote crafted input. There is no hazard when the resulting string is sent directly to a PostgreSQL server (which would check its encoding anyway), but there is a risk when it is passed through psql or other client-side code. Historically such code has not carefully vetted encoding, and in many cases it's not clear what it should do if it did detect such a problem.

  This fix is effective only if the data-quoting function, the server, and any intermediate processing agree on the character encoding that's being used. Applications that insert untrusted input into SQL commands should take special care to ensure that that's true.

  Applications and drivers that quote untrusted input without using these libpq functions may be at risk of similar problems. They should first confirm the data is valid in the encoding expected by the server.

  The PostgreSQL Project thanks Stephen Fewer for reporting this problem. (CVE-2025-1094)

- Exclude parallel workers from connection privilege checks and limits (Tom Lane) §

  Do not check `datallowconn`, `rolcanlogin`, and `ACL_CONNECT` privileges when starting a parallel worker, instead assuming that it's enough for the leader process to have passed similar checks originally. This avoids, for example, unexpected failures of parallelized queries when the leader is running as a role that lacks login privilege. In the same vein, enforce `ReservedConnections`, `datconnlimit`, and `rolconnlimit` limits only against regular backends, and count only regular backends while checking if the limits were already reached. Those limits are meant to prevent excessive consumption of process slots for regular backends --- but parallel workers and other special processes have their own pools of process slots with their own limit checks.

- Fix possible re-use of stale results in window aggregates (David Rowley) §

  A window aggregate with a run condition optimization and a pass-by-reference result type might incorrectly return the result from the previous partition instead of performing a fresh calculation.

- Keep `TransactionXmin` in sync with `MyProc->xmin` (Heikki Linnakangas) §

  This oversight could permit a process to try to access data that had already been vacuumed away. One known consequence is transient could not access status of transaction errors.

- Fix race condition that could cause failure to add a newly-inserted catalog entry to a catalog cache list (Heikki Linnakangas) §

  This could result, for example, in failure to use a newly-created function within an existing session.

- Prevent possible catalog corruption when a system catalog is vacuumed concurrently with an update (Noah Misch) §

- Fix data corruption when relation truncation fails (Thomas Munro) § § §

  The filesystem calls needed to perform relation truncation could fail, leaving inconsistent state on disk (for example, effectively reviving deleted data). We can't really prevent that, but we can recover by dint of making such failures into PANICs, so that consistency is restored by replaying from WAL up to just before the attempted truncation. This isn't a hugely desirable behavior, but such failures are rare enough that it seems an acceptable solution.

- Prevent checkpoints from starting during relation truncation (Robert Haas) §

  This avoids a race condition wherein the modified file might not get fsync'd before completing the checkpoint, creating a risk of data corruption if the operating system crashes soon after.

- Use `rename()` not `link()`/`unlink()` to rename files (Nathan Bossart) §

  The previous coding was intended to assure that the operation could not accidentally overwrite an existing file. However a failure could leave two links to the same file in existence, confusing subsequent operations and creating a risk of data corruption. In practice we do not use this functionality in places where the target filename could already exist, so it seems better to give up the no-overwrite guarantee to remove the multiple-link hazard.

- Avoid possibly losing an update of pg_database.datfrozenxid when `VACUUM` runs concurrently with a `REASSIGN OWNED` that changes that database's owner (Kirill Reshke) §

- Fix incorrect tg_updatedcols values passed to `AFTER UPDATE` triggers (Tom Lane) §

  In some cases the tg_updatedcols bitmap could describe the set of columns updated by an earlier command in the same transaction, fooling the trigger into doing the wrong thing.

  Also, prevent memory bloat caused by making too many copies of the tg_updatedcols bitmap.

- Fix detach of a partition that has its own foreign-key constraint referencing a partitioned table (Amul Sul) §

  In common cases, foreign keys are defined on a partitioned table's top level; but if instead one is defined on a partition and references a partitioned table, and the referencing partition is detached, the relevant pg_constraint entries were updated incorrectly. This led to errors like could not find ON INSERT check triggers of foreign key constraint.

- Fix mis-processing of `to_timestamp`'s `FF`n`` format codes (Tom Lane) §

  An integer format code immediately preceding `FF`n`` would consume all available digits, leaving none for `FF`n``.

- When deparsing an `XMLTABLE()` expression, ensure that XML namespace names are double-quoted when necessary (Dean Rasheed) §

- Include the `ldapscheme` option in `pg_hba_file_rules()` output (Laurenz Albe) § §

- Don't merge `UNION` operations if their column collations aren't consistent (Tom Lane) §

  Previously we ignored collations when deciding if it's safe to merge `UNION` steps into a single N-way `UNION` operation. This was arguably valid before the introduction of nondeterministic collations, but it's not anymore, since the collation in use can affect the definition of uniqueness.

- Fix missed expression processing for partition pruning steps (Tom Lane) §

  This oversight could lead to unrecognized node type errors, and perhaps other problems, in queries accessing partitioned tables.

- Allow dshash tables to grow past 1GB (Matthias van de Meent) §

  This avoids errors like invalid DSA memory alloc request size. The case can occur for example in transactions that process several million tables.

- Avoid possible integer overflow in `bringetbitmap()` (James Hunter, Evgeniy Gorbanyov) §

  Since the result is only used for statistical purposes, the effects of this error were mostly cosmetic.

- Prevent streaming standby servers from looping infinitely when reading a WAL record that crosses pages (Kyotaro Horiguchi, Alexander Kukushkin) §

  This would happen when the record's continuation is on a page that needs to be read from a different WAL source.

- Fix unintended promotion of FATAL errors to PANIC during early process startup (Noah Misch) §

  This fixes some unlikely cases that would result in PANIC: proc_exit() called in child process.

- Fix cases where an operator family member operator or support procedure could become a dangling reference (Tom Lane) § §

  In some cases a data type could be dropped while references to its OID still remain in pg_amop or pg_amproc. While that caused no immediate issues, an attempt to drop the owning operator family would fail, and pg_dump would produce bogus output when dumping the operator family. This fix causes creation and modification of operator families/classes to add needed dependency entries so that dropping a data type will also drop any dependent operator family elements. That does not help vulnerable pre-existing operator families, though, so a band-aid has also been added to `DROP OPERATOR FAMILY` to prevent failure when dropping a family that has dangling members.

- Fix multiple memory leaks in logical decoding output (Vignesh C, Masahiko Sawada, Boyu Yang) § § §

- Avoid low-probability crash on out-of-memory, due to missing check for failure return from `malloc()` (Karina Litskevich) §

- Avoid integer overflow while testing `wal_skip_threshold` condition (Tom Lane) §

  A transaction that created a very large relation could mistakenly decide to ensure durability by copying the relation into WAL instead of fsync'ing it, thereby negating the point of `wal_skip_threshold`. (This only matters when `wal_level` is set to `minimal`, else a WAL copy is required anyway.)

- Fix unsafe order of operations during cache lookups (Noah Misch) §

  The only known consequence was a usually-harmless you don't own a lock of type ExclusiveLock warning during `GRANT TABLESPACE`.

- Fix possible failed to resolve name failures when using JIT on older ARM platforms (Thomas Munro) §

  This could occur as a consequence of inconsistency about the default setting of `-moutline-atomics` between gcc and clang. At least Debian and Ubuntu are known to ship gcc and clang compilers that target armv8-a but differ on the use of outline atomics by default.

- Fix handling of Windows junction points that are not of PostgreSQL origin (Thomas Munro) § §

  Previously, initdb would fail if the path to the data directory included junction points whose expansion isn't in drive absolute format, or whose expansion points to another junction point.

- Fix assertion failure in `WITH RECURSIVE ... UNION` queries (David Rowley) §

- Avoid assertion failure in rule deparsing if a set operation leaf query contains set operations (Man Zeng, Tom Lane) §

- Avoid edge-case assertion failure in parallel query startup (Tom Lane) §

- Fix assertion failure at shutdown when writing out the statistics file (Michael Paquier) §

- In `NULLIF()`, avoid passing a read-write expanded object pointer to the data type's equality function (Tom Lane) §

  The equality function could modify or delete the object if it's given a read-write pointer, which would be bad if we decide to return it as the `NULLIF()` result. There is probably no problem with any built-in equality function, but it's easy to demonstrate a failure with one coded in PL/pgSQL.

- Ensure that expression preprocessing is applied to a default null value in `INSERT` (Tom Lane) §

  If the target column is of a domain type, the planner must insert a coerce-to-domain step not just a null constant, and this expression missed going through some required processing steps. There is no known consequence with domains based on core data types, but in theory an error could occur with domains based on extension types.

- Repair memory leaks in PL/Python (Mat Arye, Tom Lane) §

  Repeated use of `PLyPlan.execute` or `plpy.cursor` resulted in memory leakage for the duration of the calling PL/Python function.

- Fix PL/Tcl to compile with Tcl 9 (Peter Eisentraut) §

- In the ecpg preprocessor, fix possible misprocessing of cursors that reference out-of-scope variables (Tom Lane) §

- In ecpg, fix compile-time warnings about unsupported use of `COPY ... FROM STDIN` (Ryo Kanbayashi) §

  Previously, the intended warning was not issued due to a typo.

- Fix psql to safely handle file path names that are encoded in SJIS (Tom Lane) §

  Some two-byte characters in SJIS have a second byte that is equal to ASCII backslash (`\`). These characters were corrupted by path name normalization, preventing access to files whose names include such characters.

- Fix use of wrong version of `pqsignal()` in pgbench and psql (Fujii Masao, Tom Lane) §

  This error could lead to misbehavior when using the `-T` option in pgbench or the `\watch` command in psql, due to interrupted system calls not being resumed as expected.

- Fix misexecution of some nested `\if` constructs in pgbench (Michail Nikolaev) §

  An `\if` command appearing within a false (not-being-executed) `\if` branch was incorrectly treated the same as `\elif`.

- In pgbench, fix possible misdisplay of progress messages during table initialization (Yushi Ogiwara, Tatsuo Ishii, Fujii Masao) § §

- Make pg_controldata more robust against corrupted `pg_control` files (Ilyasov Ian, Anton Voloshin) §

  Since pg_controldata will attempt to print the contents of `pg_control` even if the CRC check fails, it must take care not to misbehave for invalid field values. This patch fixes some issues triggered by invalid timestamps and apparently-negative WAL segment sizes.

- Fix possible crash in pg_dump with identity sequences attached to tables that are extension members (Tom Lane) §

- Fix pg_basebackup to correctly handle `pg_wal.tar` files exceeding 2GB on Windows (Davinder Singh, Thomas Munro) § §

- Update configuration probes that determine the compiler switches needed to access ARM CRC instructions (Tom Lane) §

  On ARM platforms where the baseline CPU target lacks CRC instructions, we need to supply a `-march` switch to persuade the compiler to compile such instructions. Recent versions of gcc reject the value we were trying, leading to silently falling back to software CRC.

- During configure, if a C23 compiler is detected, try asking for C17 (Thomas Munro) §

  PostgreSQL versions before v16 will not compile under C23 rules. If the chosen compiler defaults to C23 or later, try adding a `-std=gnu17` switch to change that. (If this won't work for your compiler, manually specify `CFLAGS` with a suitable switch.)

- Update time zone data files to tzdata release 2025a for DST law changes in Paraguay, plus historical corrections for the Philippines (Tom Lane) §

## Release 15.10

## Release date:

2024-11-21

This release contains a few fixes from 15.9. For information about new features in major release 15, see release-15.

## Migration to Version 15.10

A dump/restore is not required for those running 15.X.

However, if you are upgrading from a version earlier than 15.9, see release-15-9.

## Changes

- Repair ABI break for extensions that work with struct ResultRelInfo (Tom Lane) §

  Last week's minor releases unintentionally broke binary compatibility with timescaledb and several other extensions. Restore the affected structure to its previous size, so that such extensions need not be rebuilt.

- Restore functionality of `ALTER {ROLE|DATABASE} SET role` (Tom Lane, Noah Misch) §

  The fix for CVE-2024-10978 accidentally caused settings for `role` to not be applied if they come from non-interactive sources, including previous `ALTER {ROLE|DATABASE}` commands and the `PGOPTIONS` environment variable.

- Fix cases where a logical replication slot's restart_lsn could go backwards (Masahiko Sawada) §

  Previously, restarting logical replication could sometimes cause the slot's restart point to be recomputed as an older value than had previously been advertised in pg_replication_slots. This is bad, since for example WAL files might have been removed on the basis of the later restart_lsn value, in which case replication would fail to restart.

- Avoid deleting still-needed WAL files during pg_rewind (Polina Bungina, Alexander Kukushkin) §

  Previously, in unlucky cases, it was possible for pg_rewind to remove important WAL files from the rewound demoted primary. In particular this happens if those files have been marked for archival (i.e., their `.ready` files were created) but not yet archived. Then the newly promoted node no longer has such files because of them having been recycled, but likely they are needed for recovery in the demoted node. If pg_rewind removes them, recovery is not possible anymore.

- Fix race conditions associated with dropping shared statistics entries (Kyotaro Horiguchi, Michael Paquier) §

  These bugs could lead to loss of statistics data, assertion failures, or can only drop stats once errors.

- Count index scans in `contrib/bloom` indexes in the statistics views, such as the pg_stat_user_indexes.idx_scan counter (Masahiro Ikeda) §

- Fix crash when checking to see if an index's opclass options have changed (Alexander Korotkov) §

  Some forms of `ALTER TABLE` would fail if the table has an index with non-default operator class options.

- Avoid assertion failure caused by disconnected NFA sub-graphs in regular expression parsing (Tom Lane) §

  This bug does not appear to have any visible consequences in non-assert builds.

## Release 15.9

## Release date:

2024-11-14

This release contains a variety of fixes from 15.8. For information about new features in major release 15, see release-15.

## Migration to Version 15.9

A dump/restore is not required for those running 15.X.

However, if you have ever detached a partition from a partitioned table that has a foreign-key reference to another partitioned table, and not dropped the former partition, then you may have catalog and/or data corruption to repair, as detailed in the fifth changelog entry below.

Also, if you are upgrading from a version earlier than 15.7, see release-15-7.

## Changes

- Ensure cached plans are marked as dependent on the calling role when RLS applies to a non-top-level table reference (Nathan Bossart) §

  If a CTE, subquery, sublink, security invoker view, or coercion projection in a query references a table with row-level security policies, we neglected to mark the resulting plan as potentially dependent on which role is executing it. This could lead to later query executions in the same session using the wrong plan, and then returning or hiding rows that should have been hidden or returned instead.

  The PostgreSQL Project thanks Wolfgang Walther for reporting this problem. (CVE-2024-10976)

- Make libpq discard error messages received during SSL or GSS protocol negotiation (Jacob Champion) §

  An error message received before encryption negotiation is completed might have been injected by a man-in-the-middle, rather than being real server output. Reporting it opens the door to various security hazards; for example, the message might spoof a query result that a careless user could mistake for correct output. The best answer seems to be to discard such data and rely only on libpq's own report of the connection failure.

  The PostgreSQL Project thanks Jacob Champion for reporting this problem. (CVE-2024-10977)

- Fix unintended interactions between `SET SESSION AUTHORIZATION` and `SET ROLE` (Tom Lane) § §

  The SQL standard mandates that `SET SESSION AUTHORIZATION` have a side-effect of doing `SET ROLE NONE`. Our implementation of that was flawed, creating more interaction between the two settings than intended. Notably, rolling back a transaction that had done `SET SESSION AUTHORIZATION` would revert `ROLE` to `NONE` even if that had not been the previous state, so that the effective user ID might now be different from what it had been before the transaction. Transiently setting `session_authorization` in a function `SET` clause had a similar effect. A related bug was that if a parallel worker inspected `current_setting('role')`, it saw `none` even when it should see something else.

  The PostgreSQL Project thanks Tom Lane for reporting this problem. (CVE-2024-10978)

- Prevent trusted PL/Perl code from changing environment variables (Andrew Dunstan, Noah Misch) § § §

  The ability to manipulate process environment variables such as `PATH` gives an attacker opportunities to execute arbitrary code. Therefore, trusted PLs must not offer the ability to do that. To fix `plperl`, replace `%ENV` with a tied hash that rejects any modification attempt with a warning. Untrusted `plperlu` retains the ability to change the environment.

  The PostgreSQL Project thanks Coby Abrams for reporting this problem. (CVE-2024-10979)

- Fix updates of catalog state for foreign-key constraints when attaching or detaching table partitions (Jehan-Guillaume de Rorthais, Tender Wang, Álvaro Herrera) § §

  If the referenced table is partitioned, then different catalog entries are needed for a referencing table that is stand-alone versus one that is a partition. `ATTACH/DETACH PARTITION` commands failed to perform this conversion correctly. In particular, after `DETACH` the now stand-alone table would be missing foreign-key enforcement triggers, which could result in the table later containing rows that fail the foreign-key constraint. A subsequent re-`ATTACH` could fail with surprising errors, too.

  The way to fix this is to do `ALTER TABLE DROP CONSTRAINT` on the now stand-alone table for each faulty constraint, and then re-add the constraint. If re-adding the constraint fails, then some erroneous data has crept in. You will need to manually re-establish consistency between the referencing and referenced tables, then re-add the constraint.

  This query can be used to identify broken constraints and construct the commands needed to recreate them:

      SELECT conrelid::pg_catalog.regclass AS "constrained table",
             conname AS constraint,
             confrelid::pg_catalog.regclass AS "references",
             pg_catalog.format('ALTER TABLE %s DROP CONSTRAINT %I;',
                               conrelid::pg_catalog.regclass, conname) AS "drop",
             pg_catalog.format('ALTER TABLE %s ADD CONSTRAINT %I %s;',
                               conrelid::pg_catalog.regclass, conname,
                               pg_catalog.pg_get_constraintdef(oid)) AS "add"
      FROM pg_catalog.pg_constraint c
      WHERE contype = 'f' AND conparentid = 0 AND
         (SELECT count(*) FROM pg_catalog.pg_constraint c2
          WHERE c2.conparentid = c.oid) <>
         ((SELECT count(*) FROM pg_catalog.pg_inherits i
          WHERE (i.inhparent = c.conrelid OR i.inhparent = c.confrelid) AND
            EXISTS (SELECT 1 FROM pg_catalog.pg_partitioned_table
                    WHERE partrelid = i.inhparent)) +
          CASE WHEN pg_catalog.pg_partition_root(conrelid) = confrelid THEN
                    (SELECT count(*) FROM pg_catalog.pg_partition_tree(confrelid)
                      WHERE level = 1)
               ELSE 0 END);

  Since it is possible that one or more of the `ADD CONSTRAINT` steps will fail, you should save the query's output in a file and then attempt to perform each step.

- Avoid possible crashes and could not open relation errors in queries on a partitioned table occurring concurrently with a `DETACH CONCURRENTLY` and immediate drop of a partition (Álvaro Herrera, Kuntal Gosh) § §

- Disallow `ALTER TABLE ATTACH PARTITION` if the table to be attached has a foreign key referencing the partitioned table (Álvaro Herrera) § §

  This arrangement is not supported, and other ways of creating it already fail.

- Don't use partitionwise joins or grouping if the query's collation for the key column doesn't match the partition key's collation (Jian He, Webbo Han) § §

  Such plans could produce incorrect results.

- Fix possible could not find pathkey item to sort error when the output of a `UNION ALL` member query needs to be sorted, and the sort column is an expression (Andrei Lepikhov, Tom Lane) §

- Allow cancellation of the second stage of index build for large hash indexes (Pavel Borisov) §

- Fix assertion failure or confusing error message for `COPY (`query`) TO ...`, when the `query` is rewritten by a `DO INSTEAD NOTIFY` rule (Tender Wang, Tom Lane) §

- Fix detection of skewed data during parallel hash join (Thomas Munro) §

  After repartitioning the inner side of a hash join because one partition has accumulated too many tuples, we check to see if all the partition's tuples went into the same child partition, which suggests that they all have the same hash value and further repartitioning cannot improve matters. This check malfunctioned in some cases, allowing repeated futile repartitioning which would eventually end in a resource-exhaustion error.

- Fix race condition in committing a serializable transaction (Heikki Linnakangas) §

  Mis-processing of a recently committed transaction could lead to an assertion failure or a could not access status of transaction error.

- Fix race condition in `COMMIT PREPARED` that resulted in orphaned 2PC files (wuchengwen) §

  A concurrent `PREPARE TRANSACTION` could cause `COMMIT PREPARED` to not remove the on-disk two-phase state file for the completed transaction. There was no immediate ill effect, but a subsequent crash-and-recovery could fail with could not access status of transaction, requiring manual removal of the orphaned file to restore service.

- Avoid invalid memory accesses after skipping an invalid toast index during `VACUUM FULL` (Tender Wang) §

  A list tracking yet-to-be-rebuilt indexes was not properly updated in this code path, risking assertion failures or crashes later on.

- Fix ways in which an in place catalog update could be lost (Noah Misch) § § § § § § §

  Normal row updates write a new version of the row to preserve rollback-ability of the transaction. However, certain system catalog updates are intentionally non-transactional and are done with an in-place update of the row. These patches fix race conditions that could cause the effects of an in-place update to be lost. As an example, it was possible to forget having set pg_class.relhasindex to true, preventing updates of the new index and thus causing index corruption.

- Reset catalog caches at end of recovery (Noah Misch) §

  This prevents scenarios wherein an in-place catalog update could be lost due to using stale data from a catalog cache.

- Avoid using parallel query while holding off interrupts (Francesco Degrassi, Noah Misch, Tom Lane) § §

  This situation cannot arise normally, but it can be reached with test scenarios such as using a SQL-language function as B-tree support (which would be far too slow for production usage). If it did occur it would result in an indefinite wait.

- Report the active query ID for statistics purposes at the start of processing of Bind and Execute protocol messages (Sami Imseih) §

  This allows more of the work done in extended query protocol to be attributed to the correct query.

- Guard against stack overflow in libxml2 with too-deeply-nested XML input (Tom Lane, with hat tip to Nick Wellnhofer) §

  Use `xmlXPathCtxtCompile()` rather than `xmlXPathCompile()`, because the latter fails to protect itself against recursion-to-stack-overflow in libxml2 releases before 2.13.4.

- Do not ignore a concurrent `REINDEX CONCURRENTLY` that is working on an index with predicates or expressions (Michail Nikolaev) §

  Normally, `REINDEX CONCURRENTLY` does not need to wait for other `REINDEX CONCURRENTLY` operations on other tables. However, this optimization is not applied if the other `REINDEX CONCURRENTLY` is processing an index with predicates or expressions, on the chance that such expressions contain user-defined code that accesses other tables. Careless coding created a race condition such that that rule was not applied uniformly, possibly allowing inconsistent behavior.

- Fix failed to find plan for subquery/CTE errors in `EXPLAIN` (Richard Guo, Tom Lane) § §

  This case arose while trying to print references to fields of a RECORD-type output of a subquery when the subquery has been optimized out of the plan altogether (which is possible at least in the case that it has a constant-false `WHERE` condition). Nothing remains in the plan to identify the original field names, so fall back to printing `f`N`` for the `N`'th record column. (That's actually the right thing anyway, if the record output arose from a `ROW()` constructor.)

- Disallow a `USING` clause when altering the type of a generated column (Peter Eisentraut) §

  A generated column already has an expression specifying the column contents, so including `USING` doesn't make sense.

- Ignore not-yet-defined Portals in the pg_cursors view (Tom Lane) §

  It is possible for user-defined code that inspects this view to be called while a new cursor is being set up, and if that happens a null pointer dereference would ensue. Avoid the problem by defining the view to exclude incompletely-set-up cursors.

- Prevent mis-encoding of trailing junk after numeric literal error messages (Karina Litskevich) §

  We do not allow identifiers to appear immediately following numeric literals (there must be some whitespace between). If a multibyte character immediately followed a numeric literal, the syntax error message about it included only the first byte of that character, causing bad-encoding problems both in the report to the client and in the postmaster log file.

- Avoid unexpected table_index_fetch_tuple call during logical decoding error while decoding a transaction involving insertion of a column default value (Takeshi Ideriha, Hou Zhijie) § §

- Reduce memory consumption of logical decoding (Masahiko Sawada) §

  Use a smaller default block size to store tuple data received during logical replication. This reduces memory wastage, which has been reported to be severe while processing long-running transactions, even leading to out-of-memory failures.

- Re-disable sending of stateless (TLSv1.2) session tickets (Daniel Gustafsson) §

  A previous change to prevent sending of stateful (TLSv1.3) session tickets accidentally re-enabled sending of stateless ones. Thus, while we intended to prevent clients from thinking that TLS session resumption is supported, some still did.

- Avoid wrong tuple length failure when dropping a database with many ACL (permission) entries (Ayush Tiwari) § §

- Allow adjusting the `session_authorization` and `role` settings in parallel workers (Tom Lane) §

  Our code intends to allow modifiable server settings to be set by function `SET` clauses, but not otherwise within a parallel worker. `SET` clauses failed for these two settings, though.

- Fix behavior of stable functions called from a `CALL` statement's argument list, when the `CALL` is within a PL/pgSQL `EXCEPTION` block (Tom Lane) §

  As with a similar fix in our previous quarterly releases, this case allowed such functions to be passed the wrong snapshot, causing them to see stale values of rows modified since the start of the outer transaction.

- Fix cache lookup failed for function errors in edge cases in PL/pgSQL's `CALL` (Tom Lane) §

- Fix thread safety of our fallback (non-OpenSSL) MD5 implementation on big-endian hardware (Heikki Linnakangas) §

  Thread safety is not currently a concern in the server, but it is for libpq.

- Parse libpq's `keepalives` connection option in the same way as other integer-valued options (Yuto Sasaki) §

  The coding used here rejected trailing whitespace in the option value, unlike other cases. This turns out to be problematic in ecpg's usage, for example.

- Avoid use of `pnstrdup()` in ecpglib (Jacob Champion) §

  That function will call `exit()` on out-of-memory, which is undesirable in a library. The calling code already handles allocation failures properly.

- In ecpglib, fix out-of-bounds read when parsing incorrect datetime input (Bruce Momjian, Pavel Nekrasov) §

  It was possible to try to read the location just before the start of a constant array. Real-world consequences seem minimal, though.

- Fix pg_dump's handling of identity sequences that have persistence different from their owning table's persistence (Tom Lane) §

  Since v15, it's been possible to set an identity sequence to be LOGGED when its owning table is UNLOGGED or vice versa. However, pg_dump's method for recreating that situation failed in binary-upgrade mode, causing pg_upgrade to fail when such sequences are present. Fix by introducing a new option for `ADD/ALTER COLUMN GENERATED AS IDENTITY` to allow the sequence's persistence to be set correctly at creation. Note that this means a dump from a database containing such a sequence will only load into a server of this minor version or newer.

- Include the source timeline history in pg_rewind's debug output (Heikki Linnakangas) §

  This was the intention to begin with, but a coding error caused the source history to always print as empty.

- Fix misbehavior with junction points on Windows, particularly in pg_rewind (Alexandra Wang) § § § §

  This entailed back-patching previous fixes by Thomas Munro, Peter Eisentraut, Alexander Lakhin, and Juan José Santamaría Flecha. Those changes were originally not back-patched out of caution, but they have been in use in later branches for long enough to deem them safe.

- Avoid trying to reindex temporary tables and indexes in vacuumdb and in parallel reindexdb (VaibhaveS, Michael Paquier, Fujii Masao, Nathan Bossart) § § §

  Reindexing other sessions' temporary tables cannot work, but the check to skip them was missing in some code paths, leading to unwanted failures.

- Allow inspection of sequence relations in relevant functions of `contrib/pageinspect` and `contrib/pgstattuple` (Nathan Bossart, Ayush Vatsa) § §

  This had been allowed in the past, but it got broken during the introduction of non-default access methods for tables.

- Fix incorrect LLVM-generated code on ARM64 platforms (Thomas Munro, Anthonin Bonnefoy) §

  When using JIT compilation on ARM platforms, the generated code could not support relocation distances exceeding 32 bits, allowing unlucky placement of generated code to cause server crashes on large-memory systems.

- Fix a few places that assumed that process start time (represented as a `time_t`) will fit into a `long` value (Max Johnson, Nathan Bossart) §

  On platforms where `long` is 32 bits (notably Windows), this coding would fail after Y2038. Most of the failures appear only cosmetic, but notably `pg_ctl start` would hang.

- Fix building with Strawberry Perl on Windows (Andrew Dunstan) §

- Prevent missing declaration for inet_pton compiler warning or error when building with MinGW (Thomas Munro, Andrew Dunstan) §

- Update time zone data files to tzdata release 2024b (Tom Lane) § §

  This tzdata release changes the old System-V-compatibility zone names to duplicate the corresponding geographic zones; for example `PST8PDT` is now an alias for `America/Los_Angeles`. The main visible consequence is that for timestamps before the introduction of standardized time zones, the zone is considered to represent local mean solar time for the named location. For example, in `PST8PDT`, `timestamptz` input such as `1801-01-01 00:00` would previously have been rendered as `1801-01-01 00:00:00-08`, but now it is rendered as `1801-01-01 00:00:00-07:52:58`.

  Also, historical corrections for Mexico, Mongolia, and Portugal. Notably, `Asia/Choibalsan` is now an alias for `Asia/Ulaanbaatar` rather than being a separate zone, mainly because the differences between those zones were found to be based on untrustworthy data.

## Release 15.8

## Release date:

2024-08-08

This release contains a variety of fixes from 15.7. For information about new features in major release 15, see release-15.

## Migration to Version 15.8

A dump/restore is not required for those running 15.X.

However, if you are upgrading from a version earlier than 15.7, see release-15-7.

## Changes

- Prevent unauthorized code execution during pg_dump (Masahiko Sawada) §

  An attacker able to create and drop non-temporary objects could inject SQL code that would be executed by a concurrent pg_dump session with the privileges of the role running pg_dump (which is often a superuser). The attack involves replacing a sequence or similar object with a view or foreign table that will execute malicious code. To prevent this, introduce a new server parameter `restrict_nonsystem_relation_kind` that can disable expansion of non-builtin views as well as access to foreign tables, and teach pg_dump to set it when available. Note that the attack is prevented only if both pg_dump and the server it is dumping from are new enough to have this fix.

  The PostgreSQL Project thanks Noah Misch for reporting this problem. (CVE-2024-7348)

- Prevent infinite loop in `VACUUM` (Melanie Plageman) §

  After a disconnected standby server with an old running transaction reconnected to the primary, it was possible for `VACUUM` on the primary to get confused about which tuples are removable, resulting in an infinite loop.

- Fix failure after attaching a table as a partition, if the table had previously had inheritance children (Álvaro Herrera) §

- Fix `ALTER TABLE DETACH PARTITION` for cases involving inconsistent index-based constraints (Álvaro Herrera, Tender Wang) § §

  When a partitioned table has an index that is not associated with a constraint, but a partition has an equivalent index that is, then detaching the partition would misbehave, leaving the ex-partition's constraint with an incorrect coninhcount value. This would cause trouble during any further manipulations of that constraint.

- Fix partition pruning setup during `ALTER TABLE DETACH PARTITION CONCURRENTLY` (Álvaro Herrera) § §

  The executor assumed that no partition could be detached between planning and execution of a query on a partitioned table. This is no longer true since the introduction of `DETACH PARTITION`'s `CONCURRENTLY` option, making it possible for query execution to fail transiently when that is used.

- Correctly update a partitioned table's pg_class.reltuples field to zero after its last child partition is dropped (Noah Misch) §

  The first `ANALYZE` on such a partitioned table must update relhassubclass as well, and that caused the reltuples update to be lost.

- Fix handling of polymorphic output arguments for procedures (Tom Lane) § §

  The SQL `CALL` statement did not resolve the correct data types for such arguments, leading to errors such as cannot display a value of type anyelement, or even outright crashes. (But `CALL` in PL/pgSQL worked correctly.)

- Fix behavior of stable functions called from a `CALL` statement's argument list (Tom Lane) §

  If the `CALL` is within an atomic context (e.g. there's an outer transaction block), such functions were passed the wrong snapshot, causing them to see stale values of rows modified since the start of the outer transaction.

- Detect integer overflow in `money` calculations (Joseph Koshakow) §

  None of the arithmetic functions for the `money` type checked for overflow before, so they would silently give wrong answers for overflowing cases.

- Fix over-aggressive clamping of the scale argument in `round(numeric)` and `trunc(numeric)` (Dean Rasheed) §

  These functions clamped their scale argument to +/-2000, but there are valid use-cases for it to be larger; the functions returned incorrect results in such cases. Instead clamp to the actual allowed range of type `numeric`.

- Fix result for `pg_size_pretty()` when applied to the smallest possible `bigint` value (Joseph Koshakow) §

- Prevent `pg_sequence_last_value()` from failing on unlogged sequences on standby servers and on temporary sequences of other sessions (Nathan Bossart) §

  Make it return NULL in these cases instead of throwing an error.

- Fix parsing of ignored operators in `websearch_to_tsquery()` (Tom Lane) §

  Per the manual, punctuation in the input of `websearch_to_tsquery()` is ignored except for the special cases of dashes and quotes. However, parentheses and a few other characters appearing immediately before an `or` could cause `or` to be treated as a data word, rather than as an `OR` operator as expected.

- Detect another integer overflow case while computing new array dimensions (Joseph Koshakow) §

  Reject applying array dimensions `[-2147483648:2147483647]` to an empty array. This is closely related to CVE-2023-5869, but appears harmless since the array still ends up empty.

- Detect another case of a new catalog cache entry becoming stale while detoasting its fields (Noah Misch) §

  An in-place update occurring while we expand out-of-line fields in a catalog tuple could be missed, leading to a catalog cache entry that lacks the in-place change but is not known to be stale. This is only possible in the pg_database catalog, so the effects are narrow, but misbehavior is possible.

- Correctly check updatability of view columns targeted by `INSERT` ... `DEFAULT` (Tom Lane) §

  If such a column is non-updatable, we should give an error reporting that. But the check was missed and then later code would report an unhelpful error such as attribute number `N` not found in view targetlist.

- Avoid reporting an unhelpful internal error for incorrect recursive queries (Tom Lane) §

  Rearrange the order of error checks so that we throw an on-point error when a `WITH RECURSIVE` query does not have a self-reference within the second arm of the `UNION`, but does have one self-reference in some other place such as `ORDER BY`.

- Lock owned sequences during `ALTER TABLE SET LOGGED|UNLOGGED` (Noah Misch) §

  These commands change the persistence of a table's owned sequences along with the table, but they failed to acquire lock on the sequences while doing so. This could result in losing the effects of concurrent `nextval()` calls.

- Don't throw an error if a queued `AFTER` trigger no longer exists (Tom Lane) §

  It's possible for a transaction to execute an operation that queues a deferred `AFTER` trigger for later execution, and then to drop the trigger before that happens. Formerly this led to weird errors such as could not find trigger `NNNN`. It seems better to silently do nothing if the trigger no longer exists at the time when it would have been executed.

- Fix failure to remove pg_init_privs entries for column-level privileges when their table is dropped (Tom Lane) §

  If an extension grants some column-level privileges on a table it creates, relevant catalog entries would remain behind after the extension is dropped. This was harmless until/unless the table's OID was re-used for another relation, when it could interfere with what pg_dump dumps for that relation.

- Fix selection of an arbiter index for `ON CONFLICT` when the desired index has expressions or predicates (Tom Lane) §

  If a query using `ON CONFLICT` accesses the target table through an updatable view, it could fail with there is no unique or exclusion constraint matching the ON CONFLICT specification, even though a matching index does exist.

- Refuse to modify a temporary table of another session with `ALTER TABLE` (Tom Lane) §

  Permissions checks normally would prevent this case from arising, but it is possible to reach it by altering a parent table whose child is another session's temporary table. Throw an error if we discover that such a child table belongs to another session.

- Fix handling of extended statistics on expressions in `CREATE TABLE LIKE STATISTICS` (Tom Lane) §

  The `CREATE` command failed to adjust column references in statistics expressions to the possibly-different column numbering of the new table. This resulted in invalid statistics objects that would cause problems later. A typical scenario where renumbering columns is needed is when the source table contains some dropped columns.

- Fix failure to recalculate sub-queries generated from `MIN()` or `MAX()` aggregates (Tom Lane) §

  In some cases the aggregate result computed at one row of the outer query could be re-used for later rows when it should not be. This has only been seen to happen when the outer query uses `DISTINCT` that is implemented with hash aggregation, but other cases may exist.

- Avoid crashing when a JIT-inlined backend function throws an error (Tom Lane) §

  The error state can include pointers into the dynamically loaded module holding the JIT-compiled code (for error location strings). In some code paths the module could get unloaded before the error report is processed, leading to SIGSEGV when the location strings are accessed.

- Cope with behavioral changes in libxml2 version 2.13.x (Erik Wienhold, Tom Lane) §

  Notably, we now suppress chunk is not well balanced errors from libxml2, unless that is the only reported error. This is to make error reports consistent between 2.13.x and earlier libxml2 versions. In earlier versions, that message was almost always redundant or outright incorrect, so 2.13.x substantially reduced the number of cases in which it's reported.

- Fix handling of subtransactions of prepared transactions when starting a hot standby server (Heikki Linnakangas) §

  When starting a standby's replay at a shutdown checkpoint WAL record, transactions that had been prepared but not yet committed on the primary are correctly understood as being still in progress. But subtransactions of a prepared transaction (created by savepoints or PL/pgSQL exception blocks) were not accounted for and would be treated as aborted. That led to inconsistency if the prepared transaction was later committed.

- Prevent incorrect initialization of logical replication slots (Masahiko Sawada) §

  In some cases a replication slot's start point within the WAL stream could be set to a point within a transaction, leading to assertion failures or incorrect decoding results.

- Avoid can only drop stats once error during replication slot creation and drop (Floris Van Nee) §

- Fix resource leakage in logical replication WAL sender (Hou Zhijie) §

  The walsender process leaked memory when publishing changes to a partitioned table whose partitions have row types physically different from the partitioned table's.

- Avoid memory leakage after servicing a notify or sinval interrupt (Tom Lane) §

  The processing functions for these events could switch the current memory context to TopMemoryContext, resulting in session-lifespan leakage of any data allocated before the incorrect setting gets replaced. There were observable leaks associated with (at least) encoding conversion of incoming queries and parameters attached to Bind messages.

- Prevent leakage of reference counts for the shared memory block used for statistics (Anthonin Bonnefoy) §

  A new backend process attaching to the statistics shared memory incremented its reference count, but failed to decrement the count when exiting. After 232 sessions had been created, the reference count would overflow to zero, causing failures in all subsequent backend process starts.

- Prevent deadlocks and assertion failures during truncation of the multixact SLRU log (Heikki Linnakangas) §

  A process trying to delete SLRU segments could deadlock with the checkpointer process.

- Avoid possibly missing end-of-input events on Windows sockets (Thomas Munro) §

  Windows reports an FD_CLOSE event only once after the remote end of the connection disconnects. With unlucky timing, we could miss that report and wait indefinitely, or at least until a timeout elapsed, expecting more input.

- Fix buffer overread in JSON parse error reports for incomplete byte sequences (Jacob Champion) §

  It was possible to walk off the end of the input buffer by a few bytes when the last bytes comprise an incomplete multi-byte character. While usually harmless, in principle this could cause a crash.

- Disable creation of stateful TLS session tickets by OpenSSL (Daniel Gustafsson) § § §

  This avoids possible failures with clients that think receipt of a session ticket means that TLS session resumption is supported.

- When replanning a PL/pgSQL simple expression, check it's still simple (Tom Lane) §

  Certain fairly-artificial cases, such as dropping a referenced function and recreating it as an aggregate, could lead to surprising failures such as unexpected plan node type.

- Fix incompatibility between PL/Perl and Perl 5.40 (Andrew Dunstan) §

- Fix recursive `RECORD`-returning PL/Python functions (Tom Lane) §

  If we recurse to a new call of the same function that passes a different column definition list (`AS` clause), it would fail because the inner call would overwrite the outer call's idea of what rowtype to return.

- Don't corrupt PL/Python's `TD` dictionary during a recursive trigger call (Tom Lane) §

  If a PL/Python-language trigger caused another one to be invoked, the `TD` dictionary created for the inner one would overwrite the outer one's `TD` dictionary.

- Fix PL/Tcl's reporting of invalid list syntax in the result of a function returning tuple (Erik Wienhold, Tom Lane) §

  Such a case could result in a crash, or in emission of misleading context information that actually refers to the previous Tcl error.

- Avoid non-thread-safe usage of `strerror()` in libpq (Peter Eisentraut) §

  Certain error messages returned by OpenSSL could become garbled in multi-threaded applications.

- Avoid memory leak within pg_dump during a binary upgrade (Daniel Gustafsson) §

- Ensure that `pg_restore` `-l` reports dependent TOC entries correctly (Tom Lane) §

  If `-l` was specified together with selective-restore options such as `-n` or `-N`, dependent TOC entries such as comments would be omitted from the listing, even when an actual restore would have selected them.

- Avoid cursor can only scan forward error in `contrib/postgres_fdw` (Etsuro Fujita) §

  This error could occur if the remote server is v15 or later and a foreign table is mapped to a non-trivial remote view.

- In `contrib/postgres_fdw`, do not send `FETCH FIRST WITH TIES` clauses to the remote server (Japin Li) §

  The remote server might not implement this clause, or might interpret it differently than we would locally, so don't risk attempting remote execution.

- Avoid clashing with system-provided `<regex.h>` headers (Thomas Munro) §

  This fixes a compilation failure on macOS version 15 and up.

- Fix otherwise-harmless assertion failure in Memoize cost estimation (David Rowley) §

- Fix otherwise-harmless assertion failures in `REINDEX CONCURRENTLY` applied to an SP-GiST index (Tom Lane) §

## Release 15.7

## Release date:

2024-05-09

This release contains a variety of fixes from 15.6. For information about new features in major release 15, see release-15.

## Migration to Version 15.7

A dump/restore is not required for those running 15.X.

However, a security vulnerability was found in the system views pg_stats_ext and pg_stats_ext_exprs, potentially allowing authenticated database users to see data they shouldn't. If this is of concern in your installation, follow the steps in the first changelog entry below to rectify it.

Also, if you are upgrading from a version earlier than 15.6, see release-15-6.

## Changes

- Restrict visibility of pg_stats_ext and pg_stats_ext_exprs entries to the table owner (Nathan Bossart) §

  These views failed to hide statistics for expressions that involve columns the accessing user does not have permission to read. View columns such as most_common_vals might expose security-relevant data. The potential interactions here are not fully clear, so in the interest of erring on the side of safety, make rows in these views visible only to the owner of the associated table.

  The PostgreSQL Project thanks Lukas Fittl for reporting this problem. (CVE-2024-4317)

  By itself, this fix will only fix the behavior in newly initdb'd database clusters. If you wish to apply this change in an existing cluster, you will need to do the following:

  1. Find the SQL script `fix-CVE-2024-4317.sql` in the `share` directory of the PostgreSQL installation (typically located someplace like `/usr/share/postgresql/`). Be sure to use the script appropriate to your PostgreSQL major version. If you do not see this file, either your version is not vulnerable (only v14–v16 are affected) or your minor version is too old to have the fix.

  2. In each database of the cluster, run the `fix-CVE-2024-4317.sql` script as superuser. In psql this would look like

         \i /usr/share/postgresql/fix-CVE-2024-4317.sql

     (adjust the file path as appropriate). Any error probably indicates that you've used the wrong script version. It will not hurt to run the script more than once.

  3. Do not forget to include the `template0` and `template1` databases, or the vulnerability will still exist in databases you create later. To fix `template0`, you'll need to temporarily make it accept connections. Do that with

         ALTER DATABASE template0 WITH ALLOW_CONNECTIONS true;

     and then after fixing `template0`, undo it with

         ALTER DATABASE template0 WITH ALLOW_CONNECTIONS false;

- Fix `INSERT` from multiple `VALUES` rows into a target column that is a domain over an array or composite type (Tom Lane) §

  Such cases would either fail with surprising complaints about mismatched datatypes, or insert unexpected coercions that could lead to odd results.

- Require `SELECT` privilege on the target table for `MERGE` with a `DO NOTHING` clause (Álvaro Herrera) §

  `SELECT` privilege would be required in all practical cases anyway, but require it even if the query reads no columns of the target table. This avoids an edge case in which `MERGE` would require no privileges whatever, which seems undesirable even when it's a do-nothing command.

- Fix handling of self-modified tuples in `MERGE` (Dean Rasheed) §

  Throw an error if a target row joins to more than one source row, as required by the SQL standard. (The previous coding could silently ignore this condition if a concurrent update was involved.) Also, throw a non-misleading error if a target row is already updated by a later command in the current transaction, thanks to a `BEFORE` trigger or a volatile function used in the query.

- Fix incorrect pruning of NULL partition when a table is partitioned on a boolean column and the query has a boolean `IS NOT` clause (David Rowley) §

  A NULL value satisfies a clause such as ``boolcol` IS NOT FALSE`, so pruning away a partition containing NULLs yielded incorrect answers.

- Make `ALTER FOREIGN TABLE SET SCHEMA` move any owned sequences into the new schema (Tom Lane) §

  Moving a regular table to a new schema causes any sequences owned by the table to be moved to that schema too (along with indexes and constraints). This was overlooked for foreign tables, however.

- Make `ALTER TABLE ... ADD COLUMN` create identity/serial sequences with the same persistence as their owning tables (Peter Eisentraut) §

  `CREATE UNLOGGED TABLE` will make any owned sequences be unlogged too. `ALTER TABLE` missed that consideration, so that an added identity column would have a logged sequence, which seems pointless.

- Improve `ALTER TABLE ... ALTER COLUMN TYPE`'s error message when there is a dependent function or publication (Tom Lane) § §

- In `CREATE DATABASE`, recognize strategy keywords case-insensitively for consistency with other options (Tomas Vondra) §

- Fix `EXPLAIN`'s counting of heap pages accessed by a bitmap heap scan (Melanie Plageman) §

  Previously, heap pages that contain no visible tuples were not counted; but it seems more consistent to count all pages returned by the bitmap index scan.

- Fix `EXPLAIN`'s output for subplans in `MERGE` (Dean Rasheed) §

  `EXPLAIN` would sometimes fail to properly display subplan Params referencing variables in other parts of the plan tree.

- Avoid deadlock during removal of orphaned temporary tables (Mikhail Zhilin) §

  If the session that creates a temporary table crashes without removing the table, autovacuum will eventually try to remove the orphaned table. However, an incoming session that's been assigned the same temporary namespace will do that too. If a temporary table has a dependency (such as an owned sequence) then a deadlock could result between these two cleanup attempts.

- Avoid race condition while examining per-relation frozen-XID values (Noah Misch) §

  `VACUUM`'s computation of per-database frozen-XID values from per-relation values could get confused by a concurrent update of those values by another `VACUUM`.

- Fix buffer usage reporting for parallel vacuuming (Anthonin Bonnefoy) §

  Buffer accesses performed by parallel workers were not getting counted in the statistics reported in `VERBOSE` mode.

- Disallow converting a table to a view within an outer SQL command that is using that table (Tom Lane) §

  This avoids possible crashes.

- Ensure that join conditions generated from equivalence classes are applied at the correct plan level (Tom Lane) §

  In versions before PostgreSQL 16, it was possible for generated conditions to be evaluated below outer joins when they should be evaluated above (after) the outer join, leading to incorrect query results. All versions have a similar hazard when considering joins to `UNION ALL` trees that have constant outputs for the join column in some `SELECT` arms.

- Prevent potentially-incorrect optimization of some window functions (David Rowley) §

  Disable run condition optimization of `ntile()` and `count()` with non-constant arguments. This avoids possible misbehavior with sub-selects, typically leading to errors like WindowFunc not found in subplan target lists.

- Avoid unnecessary use of moving-aggregate mode with a non-moving window frame (Vallimaharajan G) §

  When a plain aggregate is used as a window function, and the window frame start is specified as `UNBOUNDED PRECEDING`, the frame's head cannot move so we do not need to use the special (and more expensive) moving-aggregate mode. This optimization was intended all along, but due to a coding error it never triggered.

- Avoid use of already-freed data while planning partition-wise joins under GEQO (Tom Lane) §

  This would typically end in a crash or unexpected error message.

- Avoid freeing still-in-use data in Memoize (Tender Wang, Andrei Lepikhov) §

  In production builds this error frequently didn't cause any problems, as the freed data would most likely not get overwritten before it was used.

- Fix incorrectly-reported statistics kind codes in requested statistics kind `X` is not yet built error messages (David Rowley) §

- Be more careful with `RECORD`-returning functions in `FROM` (Tom Lane) § §

  The output columns of such a function call must be defined by an `AS` clause that specifies the column names and data types. If the actual function output value doesn't match that, an error is supposed to be thrown at runtime. However, some code paths would examine the actual value prematurely, and potentially issue strange errors or suffer assertion failures if it doesn't match expectations.

- Fix confusion about the return rowtype of SQL-language procedures (Tom Lane) §

  A procedure implemented in SQL language that returns a single composite-type column would cause an assertion failure or core dump.

- Add protective stack depth checks to some recursive functions (Egor Chindyaskin) §

- Fix mis-rounding and overflow hazards in `date_bin()` (Moaaz Assali) §

  In the case where the source timestamp is before the origin timestamp and their difference is already an exact multiple of the stride, the code incorrectly subtracted the stride anyway. Also, detect some integer-overflow cases that would have produced incorrect results.

- Detect integer overflow when adding or subtracting an `interval` to/from a `timestamp` (Joseph Koshakow) §

  Some cases that should cause an out-of-range error produced an incorrect result instead.

- Avoid race condition in `pg_get_expr()` (Tom Lane) §

  If the relation referenced by the argument is dropped concurrently, the function's intention is to return NULL, but sometimes it failed instead.

- Fix detection of old transaction IDs in XID status functions (Karina Litskevich) §

  Transaction IDs more than 231 transactions in the past could be misidentified as recent, leading to misbehavior of `pg_xact_status()` or `txid_status()`.

- Ensure that a table's freespace map won't return a page that's past the end of the table (Ronan Dunklau) §

  Because the freespace map isn't WAL-logged, this was possible in edge cases involving an OS crash, a replica promote, or a PITR restore. The result would be a could not read block error.

- Fix file descriptor leakage when an error is thrown while waiting in `WaitEventSetWait` (Etsuro Fujita) §

- Avoid corrupting exception stack if an FDW implements async append but doesn't configure any wait conditions for the Append plan node to wait for (Alexander Pyhalov) §

- Throw an error if an index is accessed while it is being reindexed (Tom Lane) §

  Previously this was just an assertion check, but promote it into a regular runtime error. This will provide a more on-point error message when reindexing a user-defined index expression that attempts to access its own table.

- Ensure that index-only scans on `name` columns return a fully-padded value (David Rowley) §

  The value physically stored in the index is truncated, and previously a pointer to that value was returned to callers. This provoked complaints when testing under valgrind. In theory it could result in crashes, though none have been reported.

- Fix race condition in deciding whether a table sync operation is needed in logical replication (Vignesh C) §

  An invalidation event arriving while a subscriber identifies which tables need to be synced would be forgotten about, so that any tables newly in need of syncing might not get processed in a timely fashion.

- Fix crash with DSM allocations larger than 4GB (Heikki Linnakangas) §

- Disconnect if a new server session's client socket cannot be put into non-blocking mode (Heikki Linnakangas) §

  It was once theoretically possible for us to operate with a socket that's in blocking mode; but that hasn't worked fully in a long time, so fail at connection start rather than misbehave later.

- Fix inadequate error reporting with OpenSSL 3.0.0 and later (Heikki Linnakangas, Tom Lane) §

  System-reported errors passed through by OpenSSL were reported with a numeric error code rather than anything readable.

- Avoid concurrent calls to `bindtextdomain()` in libpq and ecpglib (Tom Lane) § §

  Although GNU gettext's implementation seems to be fine with concurrent calls, the version available on Windows is not.

- Fix crash in ecpg's preprocessor if the program tries to redefine a macro that was defined on the preprocessor command line (Tom Lane) § § §

- In ecpg, avoid issuing false unsupported feature will be passed to server warnings (Tom Lane) §

- Ensure that the string result of ecpg's `intoasc()` function is correctly zero-terminated (Oleg Tselebrovskiy) §

- In psql, avoid leaking a query result after the query is cancelled (Tom Lane) §

  This happened only when cancelling a non-last query in a query string made with `\;` separators.

- Fix pg_dumpall so that role comments, if present, will be dumped regardless of the setting of `--no-role-passwords` (Daniel Gustafsson, Álvaro Herrera) §

- Skip files named `.DS_Store` in pg_basebackup, pg_checksums, and pg_rewind (Daniel Gustafsson) §

  This avoids problems on macOS, where the Finder may create such files.

- Fix PL/pgSQL's parsing of single-line comments (`--`-style comments) following expressions (Erik Wienhold, Tom Lane) §

  This mistake caused parse errors if such a comment followed a `WHEN` expression in a PL/pgSQL `CASE` statement.

- In `contrib/amcheck`, don't report false match failures due to short- versus long-header values (Andrey Borodin, Michael Zhilin) § §

  A variable-length datum in a heap tuple or index tuple could have either a short or a long header, depending on compression parameters that applied when it was made. Treat these cases as equivalent rather than complaining if there's a difference.

- Fix bugs in BRIN output functions (Tomas Vondra) §

  These output functions are only used for displaying index entries in `contrib/pageinspect`, so the errors are of limited practical concern.

- In `contrib/postgres_fdw`, avoid emitting requests to sort by a constant (David Rowley) §

  This could occur in cases involving `UNION ALL` with constant-emitting subqueries. Sorting by a constant is useless of course, but it also risks being misinterpreted by the remote server, leading to ORDER BY position `N` is not in select list errors.

- Make `contrib/postgres_fdw` set the remote session's time zone to `GMT` not `UTC` (Tom Lane) §

  This should have the same results for practical purposes. However, `GMT` is recognized by hard-wired code in the server, while `UTC` is looked up in the timezone database. So the old code could fail in the unlikely event that the remote server's timezone database is missing entries.

- In `contrib/xml2`, avoid use of library functions that have been deprecated in recent versions of libxml2 (Dmitry Koval) §

- Fix incompatibility with LLVM 18 (Thomas Munro, Dmitry Dolgov) §

- Allow `make check` to work with the musl C library (Thomas Munro, Bruce Momjian, Tom Lane) §

## Release 15.6

## Release date:

2024-02-08

This release contains a variety of fixes from 15.5. For information about new features in major release 15, see release-15.

## Migration to Version 15.6

A dump/restore is not required for those running 15.X.

However, one bug was fixed that could have resulted in corruption of GIN indexes during concurrent updates. If you suspect such corruption, reindex affected indexes after installing this update.

Also, if you are upgrading from a version earlier than 15.5, see release-15-5.

## Changes

- Tighten security restrictions within `REFRESH MATERIALIZED VIEW CONCURRENTLY` (Heikki Linnakangas) § §

  One step of a concurrent refresh command was run under weak security restrictions. If a materialized view's owner could persuade a superuser or other high-privileged user to perform a concurrent refresh on that view, the view's owner could control code executed with the privileges of the user running `REFRESH`. Fix things so that all user-determined code is run as the view's owner, as expected.

  The only known exploit for this error does not work in PostgreSQL 16.0 and later, so it may be that v16 is not vulnerable in practice.

  The PostgreSQL Project thanks Pedro Gallegos for reporting this problem. (CVE-2024-0985)

- Fix memory leak when performing JIT inlining (Andres Freund, Daniel Gustafsson) §

  There have been multiple reports of backend processes suffering out-of-memory conditions after sufficiently many JIT compilations. This fix should resolve that.

- When dequeueing from an LWLock, avoid needing to search the list of waiting processes (Andres Freund) §

  This fixes O(N^2) behavior when the list of waiters is long. In some use-cases this results in substantial throughput improvements.

- Avoid generating incorrect partitioned-join plans (Richard Guo) §

  Some uncommon situations involving lateral references could create incorrect plans. Affected queries could produce wrong answers, or odd failures such as variable not found in subplan target list, or executor crashes.

- Fix incorrect wrapping of subquery output expressions in PlaceHolderVars (Tom Lane) §

  This fixes incorrect results when a subquery is underneath an outer join and has an output column that laterally references something outside the outer join's scope. The output column might not appear as NULL when it should do so due to the action of the outer join.

- Fix misprocessing of window function run conditions (Richard Guo) §

  This oversight could lead to WindowFunc not found in subplan target lists errors.

- Skip inappropriate actions when `MERGE` causes a cross-partition update (Dean Rasheed) §

  When executing a `MERGE UPDATE` action on a partitioned table, if the `UPDATE` is turned into a `DELETE` and `INSERT` due to changing a partition key column, skip firing `AFTER UPDATE ROW` triggers, as well as other post-update actions such as RLS checks. These actions would typically fail, which is why a regular `UPDATE` doesn't do them in such cases; `MERGE` shouldn't either.

- Cope with `BEFORE ROW DELETE` triggers in cross-partition `MERGE` updates (Dean Rasheed) §

  If such a trigger attempted to prevent the update by returning NULL, `MERGE` would suffer an error or assertion failure.

- Prevent access to a no-longer-pinned buffer in `BEFORE ROW UPDATE` triggers (Alexander Lakhin, Tom Lane) §

  If the tuple being updated had just been updated and moved to another page by another session, there was a narrow window where we would attempt to fetch data from the new tuple version without any pin on its buffer. In principle this could result in garbage data appearing in non-updated columns of the proposed new tuple. The odds of problems in practice seem rather low, however.

- Avoid requesting an oversize shared-memory area in parallel hash join (Thomas Munro, Andrei Lepikhov, Alexander Korotkov) § §

  The limiting value was too large, allowing invalid DSA memory alloc request size errors to occur with sufficiently large expected hash table sizes.

- Avoid assertion failures in `heap_update()` and `heap_delete()` when a tuple to be updated by a foreign-key enforcement trigger fails the extra visibility crosscheck (Alexander Lakhin) §

  This error had no impact in non-assert builds.

- Fix overly tight assertion about `false_positive_rate` parameter of BRIN bloom operator classes (Alexander Lakhin) §

  This error had no impact in non-assert builds, either.

- Fix possible failure during `ALTER TABLE ADD COLUMN` on a complex inheritance tree (Tender Wang) §

  If a grandchild table would inherit the new column via multiple intermediate parents, the command failed with tuple already updated by self.

- Fix problems with duplicate token names in `ALTER TEXT SEARCH CONFIGURATION ... MAPPING` commands (Tender Wang, Michael Paquier) §

- Properly lock the associated table during `DROP STATISTICS` (Tomas Vondra) §

  Failure to acquire the lock could result in tuple concurrently deleted errors if the `DROP` executes concurrently with `ANALYZE`.

- Fix function volatility checking for `GENERATED` and `DEFAULT` expressions (Tom Lane) §

  These places could fail to detect insertion of a volatile function default-argument expression, or decide that a polymorphic function is volatile although it is actually immutable on the datatype of interest. This could lead to improperly rejecting or accepting a `GENERATED` clause, or to mistakenly applying the constant-default-value optimization in `ALTER TABLE ADD COLUMN`.

- Detect that a new catalog cache entry became stale while detoasting its fields (Tom Lane) § §

  We expand any out-of-line fields in a catalog tuple before inserting it into the catalog caches. That involves database access which might cause invalidation of catalog cache entries — but the new entry isn't in the cache yet, so we would miss noticing that it should get invalidated. The result is a race condition in which an already-stale cache entry could get made, and then persist indefinitely. This would lead to hard-to-predict misbehavior. Fix by rechecking the tuple's visibility after detoasting.

- Fix edge-case integer overflow detection bug on some platforms (Dean Rasheed) §

  Computing `0 - INT64_MIN` should result in an overflow error, and did on most platforms. However, platforms with neither integer overflow builtins nor 128-bit integers would fail to spot the overflow, instead returning `INT64_MIN`.

- Detect Julian-date overflow when adding or subtracting an `interval` to/from a `timestamp` (Tom Lane) §

  Some cases that should cause an out-of-range error produced an incorrect result instead.

- Add more checks for overflow in `interval_mul()` and `interval_div()` (Dean Rasheed) §

  Some cases that should cause an out-of-range error produced an incorrect result instead.

- Ensure cached statistics are discarded after a change to `stats_fetch_consistency` (Shinya Kato) §

  In some code paths, it was possible for stale statistics to be returned.

- Make the pg_file_settings view check validity of unapplied values for settings with `backend` or `superuser-backend` context (Tom Lane) §

  Invalid values were not noted in the view as intended. This escaped detection because there are very few settings in these groups.

- Match collation too when matching an existing index to a new partitioned index (Peter Eisentraut) §

  Previously we could accept an index that has a different collation from the corresponding element of the partition key, possibly leading to misbehavior.

- Avoid failure if a child index is dropped concurrently with `REINDEX INDEX` on a partitioned index (Fei Changhong) § §

- Fix insufficient locking when cleaning up an incomplete split of a GIN index's internal page (Fei Changhong, Heikki Linnakangas) §

  The code tried to do this with shared rather than exclusive lock on the buffer. This could lead to index corruption if two processes attempted the cleanup concurrently.

- Avoid premature release of buffer pin in GIN index insertion (Tom Lane) §

  If an index root page split occurs concurrently with our own insertion, the code could fail with buffer NNNN is not owned by resource owner.

- Avoid failure with partitioned SP-GiST indexes (Tom Lane) §

  Trying to use an index of this kind could lead to No such file or directory errors.

- Fix ownership change reporting for large objects (Tom Lane) §

  A no-op `ALTER LARGE OBJECT OWNER` command (that is, one selecting the existing owner) passed the wrong class ID to the `PostAlterHook`, probably confusing any extension using that hook.

- Fix reporting of I/O timing data in `EXPLAIN (BUFFERS)` (Michael Paquier) §

  The numbers labeled as shared/local actually refer only to shared buffers, so change that label to shared.

- Ensure durability of `CREATE DATABASE` (Noah Misch) § §

  If an operating system crash occurred during or shortly after `CREATE DATABASE`, recovery could fail, or subsequent connections to the new database could fail. If a base backup was taken in that window, similar problems could be observed when trying to use the backup. The symptom would be that the database directory, `PG_VERSION` file, or `pg_filenode.map` file was missing or empty.

- Add more `LOG` messages when starting and ending recovery from a backup (Andres Freund) §

  This change provides additional information in the postmaster log that may be useful for diagnosing recovery problems.

- Prevent standby servers from incorrectly processing dead index tuples during subtransactions (Fei Changhong) §

  The startedInRecovery flag was not correctly set for a subtransaction. This affects only processing of dead index tuples. It could allow a query in a subtransaction to ignore index entries that it should return (if they are already dead on the primary server, but not dead to the standby transaction), or to prematurely mark index entries as dead that are not yet dead on the primary. It is not clear that the latter case has any serious consequences, but it's not the intended behavior.

- Fix integer overflow hazard in checking whether a record will fit into the WAL decoding buffer (Thomas Munro) §

  This bug appears to be only latent except when running a 32-bit PostgreSQL build on a 64-bit platform.

- Fix deadlock between a logical replication apply worker, its tablesync worker, and a session process trying to alter the subscription (Shlok Kyal) §

  One edge of the deadlock loop did not involve a lock wait, so the deadlock went undetected and would persist until manual intervention.

- Ensure that column default values are correctly transmitted by the pgoutput logical replication plugin (Nikhil Benesch) §

  `ALTER TABLE ADD COLUMN` with a constant default value for the new column avoids rewriting existing tuples, instead expecting that reading code will insert the correct default into a tuple that lacks that column. If replication was subsequently initiated on the table, pgoutput would transmit NULL instead of the correct default for such a column, causing incorrect replication on the subscriber.

- Fix failure of logical replication's initial sync for a table with no columns (Vignesh C) §

  This case generated an improperly-formatted `COPY` command.

- Prevent examining system catalogs with the wrong snapshot during logical decoding (Fei Changhong) §

  If decoding begins partway through a transaction that modifies system catalogs, the decoder may not recognize that, causing it to fail to treat that transaction as in-progress for catalog lookups. This fix deals with the case that a top-level transaction is already marked as containing catalog changes, but its subtransaction(s) are not.

- Return the correct status code when a new client disconnects without responding to the server's password challenge (Liu Lang, Tom Lane) §

  In some cases we'd treat this as a loggable error, which was not the intention and tends to create log spam, since common clients like psql frequently do this. It may also confuse extensions that use `ClientAuthentication_hook`.

- Fix incompatibility with OpenSSL 3.2 (Tristan Partin, Bo Andreson) §

  Use the BIO app_data field for our private storage, instead of assuming it's okay to use the data field. This mistake didn't cause problems before, but with 3.2 it leads to crashes and complaints about double frees.

- Be more wary about OpenSSL not setting `errno` on error (Tom Lane) §

  If `errno` isn't set, assume the cause of the reported failure is read EOF. This fixes rare cases of strange error reports like could not accept SSL connection: Success.

- Fix file descriptor leakage when a foreign data wrapper's `ForeignAsyncRequest` function fails (Heikki Linnakangas) §

- Report `ENOMEM` errors from file-related system calls as `ERRCODE_OUT_OF_MEMORY`, not `ERRCODE_INTERNAL_ERROR` (Alexander Kuzmenkov) §

- In PL/pgSQL, support SQL commands that are `CREATE FUNCTION`/`CREATE PROCEDURE` with SQL-standard bodies (Tom Lane) §

  Previously, such cases failed with parsing errors due to the semicolon(s) appearing in the function body.

- Fix libpq's handling of errors in pipelines (Álvaro Herrera) § §

  The pipeline state could get out of sync if an error is returned for reasons other than a query problem (for example, if the connection is lost). Potentially this would lead to a busy-loop in the calling application.

- Make libpq's `PQsendFlushRequest()` function flush the client output buffer under the same rules as other `PQsend` functions (Jelte Fennema-Nio) §

  In pipeline mode, it may still be necessary to call `PQflush()` as well; but this change removes some inconsistency.

- Avoid race condition when libpq initializes OpenSSL support concurrently in two different threads (Willi Mann, Michael Paquier) §

- Fix timing-dependent failure in GSSAPI data transmission (Tom Lane) §

  When using GSSAPI encryption in non-blocking mode, libpq sometimes failed with GSSAPI caller failed to retransmit all data needing to be retried.

- In pg_dump, don't dump RLS policies or security labels for extension member objects (Tom Lane, Jacob Champion) § §

  Previously, commands would be included in the dump to set these properties, which is really incorrect since they should be considered as internal affairs of the extension. Moreover, the restoring user might not have adequate privilege to set them, and indeed the dumping user might not have enough privilege to dump them (since dumping RLS policies requires acquiring lock on their table).

- In pg_dump, don't dump an extended statistics object if its underlying table isn't being dumped (Rian McGuire, Tom Lane) §

  This conforms to the behavior for other dependent objects such as indexes.

- Make it an error for a pgbench script to end with an open pipeline (Anthonin Bonnefoy) §

  Previously, pgbench would behave oddly if a `\startpipeline` command lacked a matching `\endpipeline`. This seems like a scripting mistake rather than a case that pgbench needs to handle nicely, so throw an error.

- Fix crash in `contrib/intarray` if an array with an element equal to `INT_MAX` is inserted into a `gist__int_ops` index (Alexander Lakhin, Tom Lane) §

- Report a better error when `contrib/pageinspect`'s `hash_bitmap_info()` function is applied to a partitioned hash index (Alexander Lakhin, Michael Paquier) §

- Report a better error when `contrib/pgstattuple`'s `pgstathashindex()` function is applied to a partitioned hash index (Alexander Lakhin) §

- On Windows, suppress autorun options when launching subprocesses in pg_ctl and pg_regress (Kyotaro Horiguchi) § §

  When launching a child process via `cmd.exe`, pass the `/D` flag to prevent executing any autorun commands specified in the registry. This avoids possibly-surprising side effects.

- Move `is_valid_ascii()` from `mb/pg_wchar.h` to `utils/ascii.h` (Jubilee Young) §

  This change avoids the need to include `<simd.h>` in `pg_wchar.h`, which was causing problems for some third-party code.

- Fix compilation failures with libxml2 version 2.12.0 and later (Tom Lane) §

- Fix compilation failure of `WAL_DEBUG` code on Windows (Bharath Rupireddy) §

- Suppress compiler warnings from Python's header files (Peter Eisentraut, Tom Lane) §

  Our preferred compiler options provoke warnings about constructs appearing in recent versions of Python's header files. When using gcc, we can suppress these warnings with a pragma.

- Avoid deprecation warning when compiling with LLVM 18 (Thomas Munro) §

- Update time zone data files to tzdata release 2024a for DST law changes in Greenland, Kazakhstan, and Palestine, plus corrections for the Antarctic stations Casey and Vostok. Also historical corrections for Vietnam, Toronto, and Miquelon. (Tom Lane) §

## Release 15.5

## Release date:

2023-11-09

This release contains a variety of fixes from 15.4. For information about new features in major release 15, see release-15.

## Migration to Version 15.5

A dump/restore is not required for those running 15.X.

However, several mistakes have been discovered that could lead to certain types of indexes yielding wrong search results or being unnecessarily inefficient. It is advisable to `REINDEX` potentially-affected indexes after installing this update. See the fourth through seventh changelog entries below.

Also, if you are upgrading from a version earlier than 15.4, see release-15-4.

## Changes

- Fix handling of unknown-type arguments in `DISTINCT` `"any"` aggregate functions (Tom Lane) §

  This error led to a `text`-type value being interpreted as an `unknown`-type value (that is, a zero-terminated string) at runtime. This could result in disclosure of server memory following the `text` value.

  The PostgreSQL Project thanks Jingzhou Fu for reporting this problem. (CVE-2023-5868)

- Detect integer overflow while computing new array dimensions (Tom Lane) §

  When assigning new elements to array subscripts that are outside the current array bounds, an undetected integer overflow could occur in edge cases. Memory stomps that are potentially exploitable for arbitrary code execution are possible, and so is disclosure of server memory.

  The PostgreSQL Project thanks Pedro Gallegos for reporting this problem. (CVE-2023-5869)

- Prevent the `pg_signal_backend` role from signalling background workers and autovacuum processes (Noah Misch, Jelte Fennema-Nio) § §

  The documentation says that `pg_signal_backend` cannot issue signals to superuser-owned processes. It was able to signal these background processes, though, because they advertise a role OID of zero. Treat that as indicating superuser ownership. The security implications of cancelling one of these process types are fairly small so far as the core code goes (we'll just start another one), but extensions might add background workers that are more vulnerable.

  Also ensure that the `is_superuser` parameter is set correctly in such processes. No specific security consequences are known for that oversight, but it might be significant for some extensions.

  The PostgreSQL Project thanks Hemanth Sandrana and Mahendrakar Srinivasarao for reporting this problem. (CVE-2023-5870)

- Fix misbehavior during recursive page split in GiST index build (Heikki Linnakangas) §

  Fix a case where the location of a page downlink was incorrectly tracked, and introduce some logic to allow recovering from such situations rather than silently doing the wrong thing. This error could result in incorrect answers from subsequent index searches. It may be advisable to reindex all GiST indexes after installing this update.

- Prevent de-duplication of btree index entries for `interval` columns (Noah Misch) §

  There are `interval` values that are distinguishable but compare equal, for example `24:00:00` and `1 day`. This breaks assumptions made by btree de-duplication, so `interval` columns need to be excluded from de-duplication. This oversight can cause incorrect results from index-only scans. Moreover, after updating amcheck will report an error for almost all such indexes. Users should reindex any btree indexes on `interval` columns.

- Process `date` values more sanely in BRIN `datetime_minmax_multi_ops` indexes (Tomas Vondra) §

  The distance calculation for dates was backward, causing poor decisions about which entries to merge. The index still produces correct results, but is much less efficient than it should be. Reindexing BRIN `minmax_multi` indexes on `date` columns is advisable.

- Process large `timestamp` and `timestamptz` values more sanely in BRIN `datetime_minmax_multi_ops` indexes (Tomas Vondra) § §

  Infinities were mistakenly treated as having distance zero rather than a large distance from other values, causing poor decisions about which entries to merge. Also, finite-but-very-large values (near the endpoints of the representable timestamp range) could result in internal overflows, again causing poor decisions. The index still produces correct results, but is much less efficient than it should be. Reindexing BRIN `minmax_multi` indexes on `timestamp` and `timestamptz` columns is advisable if the column contains, or has contained, infinities or large finite values.

- Avoid calculation overflows in BRIN `interval_minmax_multi_ops` indexes with extreme interval values (Tomas Vondra) §

  This bug might have caused unexpected failures while trying to insert large interval values into such an index.

- Fix partition step generation and runtime partition pruning for hash-partitioned tables with multiple partition keys (David Rowley) § §

  Some cases involving an `IS NULL` condition on one of the partition keys could result in a crash.

- Fix inconsistent rechecking of concurrently-updated rows during `MERGE` (Dean Rasheed) §

  In `READ COMMITTED` mode, an update that finds that its target row was just updated by a concurrent transaction will recheck the query's `WHERE` conditions on the updated row. `MERGE` failed to ensure that the proper rows of other joined tables were used during this recheck, possibly resulting in incorrect decisions about whether the newly-updated row should be updated again by `MERGE`.

- Correctly identify the target table in an inherited `UPDATE`/`DELETE`/`MERGE` even when the parent table is excluded by constraints (Amit Langote, Tom Lane) §

  If the initially-named table is excluded by constraints, but not all its inheritance descendants are, the first non-excluded descendant was identified as the primary target table. This would lead to firing statement-level triggers associated with that table, rather than the initially-named table as should happen. In v16, the same oversight could also lead to invalid perminfoindex 0 in RTE with relid NNNN errors.

- Fix edge case in btree mark/restore processing of ScalarArrayOpExpr clauses (Peter Geoghegan) §

  When restoring an indexscan to a previously marked position, the code could miss required setup steps if the scan had advanced exactly to the end of the matches for a ScalarArrayOpExpr (that is, an `indexcol = ANY(ARRAY[])`) clause. This could result in missing some rows that should have been fetched.

- Fix intra-query memory leak in Memoize execution (Orlov Aleksej, David Rowley) §

- Fix intra-query memory leak when a set-returning function repeatedly returns zero rows (Tom Lane) §

- Don't crash if `cursor_to_xmlschema()` is applied to a non-data-returning Portal (Boyu Yang) §

- Throw the intended error if `pgrowlocks()` is applied to a partitioned table (David Rowley) §

  Previously, a not-on-point complaint only heap AM is supported would be raised.

- Handle invalid indexes more cleanly in assorted SQL functions (Noah Misch) §

  Report an error if `pgstatindex()`, `pgstatginindex()`, `pgstathashindex()`, or `pgstattuple()` is applied to an invalid index. If `brin_desummarize_range()`, `brin_summarize_new_values()`, `brin_summarize_range()`, or `gin_clean_pending_list()` is applied to an invalid index, do nothing except to report a debug-level message. Formerly these functions attempted to process the index, and might fail in strange ways depending on what the failed `CREATE INDEX` had left behind.

- Fix `pg_stat_reset_single_table_counters()` to do the right thing for a shared catalog (Masahiro Ikeda) §

  Previously the reset would be ineffective.

- Avoid premature memory allocation failure with long inputs to `to_tsvector()` (Tom Lane) §

- Fix over-allocation of the constructed `tsvector` in `tsvectorrecv()` (Denis Erokhin) §

  If the incoming vector includes position data, the binary receive function left wasted space (roughly equal to the size of the position data) in the finished `tsvector`. In extreme cases this could lead to maximum total lexeme length exceeded failures for vectors that were under the length limit when emitted. In any case it could lead to wasted space on-disk.

- Fix incorrect coding in `gtsvector_picksplit()` (Alexander Lakhin) §

  This could lead to poor page-split decisions in GiST indexes on `tsvector` columns.

- Improve checks for corrupt PGLZ compressed data (Flavien Guedez) §

- In `COPY FROM`, fail cleanly when an unsupported encoding conversion is needed (Tom Lane) §

  Recent refactoring accidentally removed the intended error check for this, such that it ended in cache lookup failed for function 0 instead of a useful error message.

- Avoid crash in `EXPLAIN` if a parameter marked to be displayed by `EXPLAIN` has a NULL boot-time value (Xing Guo, Aleksander Alekseev, Tom Lane) §

  No built-in parameter fits this description, but an extension could define such a parameter.

- Ensure we have a snapshot while dropping `ON COMMIT DROP` temp tables (Tom Lane) §

  This prevents possible misbehavior if any catalog entries for the temp tables have fields wide enough to require toasting (such as a very complex `CHECK` condition).

- Avoid improper response to shutdown signals in child processes just forked by `system()` (Nathan Bossart) §

  This fix avoids a race condition in which a child process that has been forked off by `system()`, but hasn't yet exec'd the intended child program, might receive and act on a signal intended for the parent server process. That would lead to duplicate cleanup actions being performed, which will not end well.

- Cope with torn reads of `pg_control` in frontend programs (Thomas Munro) §

  On some file systems, reading `pg_control` may not be an atomic action when the server concurrently writes that file. This is detectable via a bad CRC. Retry a few times to see if the file becomes valid before we report error.

- Avoid torn reads of `pg_control` in relevant SQL functions (Thomas Munro) §

  Acquire the appropriate lock before reading `pg_control`, to ensure we get a consistent view of that file.

- Avoid integer overflow when computing size of backend activity string array (Jakub Wartak) §

  On 64-bit machines we will allow values of `track_activity_query_size` large enough to cause 32-bit overflow when multiplied by the allowed number of connections. The code actually allocating the per-backend local array was careless about this though, and allocated the array incorrectly.

- Fix briefly showing inconsistent progress statistics for `ANALYZE` on inherited tables (Heikki Linnakangas) §

  The block-level counters should be reset to zero at the same time we update the current-relation field.

- Fix the background writer to report any WAL writes it makes to the statistics counters (Nazir Bilal Yavuz) §

- Fix confusion about forced-flush behavior in `pgstat_report_wal()` (Ryoga Yoshida, Michael Paquier) §

  This could result in some statistics about WAL I/O being forgotten in a shutdown.

- Track the dependencies of cached `CALL` statements, and re-plan them when needed (Tom Lane) §

  DDL commands, such as replacement of a function that has been inlined into a `CALL` argument, can create the need to re-plan a `CALL` that has been cached by PL/pgSQL. That was not happening, leading to misbehavior or strange errors such as cache lookup failed.

- Avoid a possible pfree-a-NULL-pointer crash after an error in OpenSSL connection setup (Sergey Shinderuk) §

- Track nesting depth correctly when inspecting `RECORD`-type Vars from outer query levels (Richard Guo) §

  This oversight could lead to assertion failures, core dumps, or bogus varno errors.

- Track hash function and negator function dependencies of ScalarArrayOpExpr plan nodes (David Rowley) §

  In most cases this oversight was harmless, since these functions would be unlikely to disappear while the node's original operator remains present.

- Fix error-handling bug in `RECORD` type cache management (Thomas Munro) §

  An out-of-memory error occurring at just the wrong point could leave behind inconsistent state that would lead to an infinite loop.

- Fix assertion failure when logical decoding is retried in the same session after an error (Hou Zhijie) §

- Treat out-of-memory failures as fatal while reading WAL (Michael Paquier) §

  Previously this would be treated as a bogus-data condition, leading to the conclusion that we'd reached the end of WAL, which is incorrect and could lead to inconsistent WAL replay.

- Fix possible recovery failure due to trying to allocate memory based on a bogus WAL record length field (Thomas Munro, Michael Paquier) § §

- Fix race condition in database dropping that could lead to the autovacuum launcher getting stuck (Andres Freund, Will Mortensen, Jacob Speidel) §

  The race could lead to a statistics entry for the removed database remaining present, confusing the launcher's selection of which database to process.

- Fix datatype size confusion in logical tape management (Ranier Vilela) §

  Integer overflow was possible on platforms where long is wider than int, although it would take a multiple-terabyte temporary file to cause a problem.

- Avoid unintended close of syslogger process's stdin (Heikki Linnakangas) §

- Avoid doing plan cache revalidation of utility statements that do not receive interesting processing during parse analysis (Tom Lane) §

  Aside from saving a few cycles, this prevents failure after a cache invalidation for statements that must not set a snapshot, such as `SET TRANSACTION ISOLATION LEVEL`.

- Keep by-reference attmissingval values in a long-lived context while they are being used (Andrew Dunstan) §

  This avoids possible use of dangling pointers when a tuple slot outlives the tuple descriptor with which its value was constructed.

- Recalculate the effective value of `search_path` after `ALTER ROLE` (Jeff Davis) § §

  This ensures that after renaming a role, the meaning of the special string `$user` is re-determined.

- Fix could not duplicate handle error occurring on Windows when `min_dynamic_shared_memory` is set above zero (Thomas Munro) §

- Fix order of operations in `GenericXLogFinish` (Jeff Davis) §

  This code violated the conditions required for crash safety by writing WAL before marking changed buffers dirty. No core code uses this function, but extensions do (`contrib/bloom` does, for example).

- Remove incorrect assertion in PL/Python exception handling (Alexander Lakhin) §

- Fix assertion failure in pg_dump when it's asked to dump the `pg_catalog` schema (Peter Eisentraut) § §

- Fix pg_restore so that selective restores will include both table-level and column-level ACLs for selected tables (Euler Taveira, Tom Lane) §

  Formerly, only the table-level ACL would get restored if both types were present.

- Add logic to pg_upgrade to check for use of `abstime`, `reltime`, and `tinterval` data types (Álvaro Herrera) § §

  These obsolete data types were removed in PostgreSQL version 12, so check to make sure they aren't present in an older database before claiming it can be upgraded.

- Avoid generating invalid temporary slot names in pg_basebackup (Jelte Fennema) §

  This has only been seen to occur when the server connection runs through pgbouncer.

- Avoid false too many client connections errors in pgbench on Windows (Noah Misch) §

- In `contrib/amcheck`, do not report interrupted page deletion as corruption (Noah Misch) §

  This fix prevents false-positive reports of the first child of leftmost target page is not leftmost of its level, block NNNN is not leftmost or left link/right link pair in index XXXX not in agreement. They appeared if amcheck ran after an unfinished btree index page deletion and before `VACUUM` had cleaned things up.

- Fix failure of `contrib/btree_gin` indexes on `interval` columns, when an indexscan using the `<` or `<=` operator is performed (Dean Rasheed) §

  Such an indexscan failed to return all the entries it should.

- Add support for LLVM 16 and 17 (Thomas Munro, Dmitry Dolgov) § § §

- Suppress assorted build-time warnings on recent macOS (Tom Lane) § §

  Xcode 15 (released with macOS Sonoma) changed the linker's behavior in a way that causes many duplicate-library warnings while building PostgreSQL. These were harmless, but they're annoying so avoid citing the same libraries twice. Also remove use of the `-multiply_defined suppress` linker switch, which apparently has been a no-op for a long time, and is now actively complained of.

- When building `contrib/unaccent`'s rules file, fall back to using `python` if `--with-python` was not given and make variable `PYTHON` was not set (Japin Li) §

- Remove `PHOT` (Phoenix Islands Time) from the default timezone abbreviations list (Tom Lane) §

  Presence of this abbreviation in the default list can cause failures on recent Debian and Ubuntu releases, as they no longer install the underlying tzdb entry by default. Since this is a made-up abbreviation for a zone with a total human population of about two dozen, it seems unlikely that anyone will miss it. If someone does, they can put it back via a custom abbreviations file.

## Release 15.4

## Release date:

2023-08-10

This release contains a variety of fixes from 15.3. For information about new features in major release 15, see release-15.

## Migration to Version 15.4

A dump/restore is not required for those running 15.X.

However, if you use BRIN indexes, it may be advisable to reindex them; see the third changelog entry below.

Also, if you are upgrading from a version earlier than 15.1, see release-15-1.

## Changes

- Disallow substituting a schema or owner name into an extension script if the name contains a quote, backslash, or dollar sign (Noah Misch) §

  This restriction guards against SQL-injection hazards for trusted extensions.

  The PostgreSQL Project thanks Micah Gates, Valerie Woolard, Tim Carey-Smith, and Christoph Berg for reporting this problem. (CVE-2023-39417)

- Fix `MERGE` to enforce row security policies properly (Dean Rasheed) §

  When `MERGE` performs an `UPDATE` action, it should enforce any `UPDATE` or `SELECT` RLS policies defined on the target table, to be consistent with the way that a plain `UPDATE` with a `WHERE` clause works. Instead it was enforcing `INSERT` RLS policies for both `INSERT` and `UPDATE` actions.

  In addition, when `MERGE` performs a `DO NOTHING` action, it applied the target table's `DELETE` RLS policies to existing rows, even though those rows are not being deleted. While it's not a security problem, this could result in unwanted errors.

  The PostgreSQL Project thanks Dean Rasheed for reporting this problem. (CVE-2023-39418)

- Fix confusion between empty (no rows) ranges and all-NULL ranges in BRIN indexes, as well as incorrect merging of all-NULL summaries (Tomas Vondra) § §

  Each of these oversights could result in forgetting that a BRIN index range contains any NULL values, potentially allowing subsequent queries that should return NULL values to miss doing so.

  This fix will not in itself correct faulty BRIN entries. It's recommended to `REINDEX` any BRIN indexes that may be used to search for nulls.

- Avoid leaving a corrupted database behind when `DROP DATABASE` is interrupted (Andres Freund) §

  If `DROP DATABASE` was interrupted after it had already begun taking irreversible steps, the target database remained accessible (because the removal of its pg_database row would roll back), but it would have corrupt contents. Fix by marking the database as inaccessible before we begin to perform irreversible operations. A failure after that will leave the database still partially present, but nothing can be done with it except to issue another `DROP DATABASE`.

- Ensure that partitioned indexes are correctly marked as valid or not at creation (Michael Paquier) §

  If a new partitioned index matches an existing but invalid index on one of the partitions, the partitioned index could end up being marked valid prematurely. This could lead to misbehavior or assertion failures in subsequent queries on the partitioned table.

- Ignore invalid child indexes when matching partitioned indexes to child indexes during `ALTER TABLE ATTACH PARTITION` (Michael Paquier) §

  Such an index will now be ignored, and a new child index created instead.

- Fix possible failure when marking a partitioned index valid after all of its partitions have been attached (Michael Paquier) §

  The update of the index's pg_index entry could use stale data for other columns. One reported symptom is an attempted to update invisible tuple error.

- Fix `ALTER EXTENSION SET SCHEMA` to complain if the extension contains any objects outside the extension's schema (Michael Paquier, Heikki Linnakangas) §

  Erroring out if the extension contains objects in multiple schemas was always intended; but the check was mis-coded so that it would fail to detect some cases, leading to surprising behavior.

- Fix tracking of tables' access method dependencies (Michael Paquier) §

  `ALTER TABLE ... SET ACCESS METHOD` failed to update relevant pg_depend entries when changing a table's access method. When using non-built-in access methods, this creates a risk that an access method could be dropped even though tables still depend on it. This fix corrects the logic in `ALTER TABLE`, but it will not adjust any already-missing pg_depend entries.

- Don't use partial unique indexes for uniqueness proofs in the planner (David Rowley) §

  This could give rise to incorrect plans, since the presumed uniqueness of rows read from a table might not hold if the index in question isn't used to scan the table.

- Don't Memoize lateral joins with volatile join conditions (Richard Guo) §

  Applying Memoize to a sub-plan that contains volatile filter conditions is likely to lead to wrong answers. The check to avoid doing this missed some cases that can arise when using `LATERAL`.

- Avoid producing incorrect plans for foreign joins with pseudoconstant join clauses (Etsuro Fujita) §

  The planner currently lacks support for attaching pseudoconstant join clauses to a pushed-down remote join, so disable generation of remote joins in such cases. (A better solution will require ABI-breaking changes of planner data structures, so it will have to wait for a future major release.)

- Correctly handle sub-SELECTs in RLS policy expressions and security-barrier views when expanding rule actions (Tom Lane) §

- Fix race conditions in conflict detection for `SERIALIZABLE` isolation mode (Thomas Munro) § § §

  Conflicts could be missed when using bitmap heap scans, when using GIN indexes, and when examining an initially-empty btree index. All these cases could lead to serializability failures due to improperly allowing conflicting transactions to commit.

- Fix misbehavior of EvalPlanQual checks with inherited or partitioned target tables (Tom Lane) §

  This oversight could lead to update or delete actions in `READ COMMITTED` isolation mode getting performed when they should have been skipped because of a conflicting concurrent update.

- Fix hash join with an inner-side hash key that contains Params coming from an outer nested loop (Tom Lane) §

  When rescanning the join after the values of such Params have changed, we must rebuild the hash table, but neglected to do so. This could result in missing join output rows.

- Fix intermittent failures when trying to update a field of a composite column (Tom Lane) §

  If the overall value of the composite column is wide enough to require out-of-line toasting, then an unluckily-timed cache flush could cause errors or server crashes.

- Prevent query-lifespan memory leaks in some `UPDATE` queries with triggers (Tomas Vondra) § §

- Prevent query-lifespan memory leaks when an Incremental Sort plan node is rescanned (James Coleman, Laurenz Albe, Tom Lane) §

- Accept fractional seconds in the input to `jsonpath`'s `datetime()` method (Tom Lane) §

- Prevent stack-overflow crashes with very complex text search patterns (Tom Lane) §

- Allow tokens up to 10240 bytes long in `pg_hba.conf` and `pg_ident.conf` (Tom Lane) §

  The previous limit of 256 bytes has been found insufficient for some use-cases.

- Ensure that all existing placeholders are checked for matches when an extension declares its GUC prefix to be reserved (Karina Litskevich, Ekaterina Sokolova) §

  Faulty loop logic could cause some entries to be skipped.

- Fix mishandling of C++ out-of-memory conditions (Heikki Linnakangas) §

  If JIT is in use, running out of memory in a C++ `new` call would lead to a PostgreSQL FATAL error, instead of the expected C++ exception.

- Fix rare null-pointer crash in `plancache.c` (Tom Lane) §

- Avoid leaking a stats entry for a subscription when it is dropped (Masahiko Sawada) §

- Avoid losing track of possibly-useful shared memory segments when a page free results in coalescing ranges of free space (Dongming Liu) §

  Ensure that the segment is moved into the appropriate bin for its new amount of free space, so that it will be found by subsequent searches.

- Allow `VACUUM` to continue after detecting certain types of b-tree index corruption (Peter Geoghegan) § §

  If an invalid sibling-page link is detected, log the issue and press on, rather than throwing an error as before. Nothing short of `REINDEX` will fix the broken index, but preventing `VACUUM` from completing until that is done risks making matters far worse.

- Ensure that `WrapLimitsVacuumLock` is released after `VACUUM` detects invalid data in pg_database.datfrozenxid or pg_database.datminmxid (Andres Freund) §

  Failure to release this lock could lead to a deadlock later, although the lock would be cleaned up if the session exits or encounters some other error.

- Avoid double replay of prepared transactions during crash recovery (suyu.cmj, Michael Paquier) § §

  After a crash partway through a checkpoint with some two-phase transaction state data already flushed to disk by this checkpoint, crash recovery could attempt to replay the prepared transaction(s) twice, leading to a fatal error such as lock is already held in the startup process.

- Ensure that a newly created, but still empty table is `fsync`'ed at the next checkpoint (Heikki Linnakangas) §

  Without this, if there is an operating system crash causing the empty file to disappear, subsequent operations on the table might fail with could not open file errors.

- Ensure that creation of the init fork of an unlogged index is WAL-logged (Heikki Linnakangas) §

  While an unlogged index's main data fork is not WAL-logged, its init fork should be, to ensure that we have a consistent state to restore the index to after a crash. This step was missed if the init fork contains no data, which is a case not used by any standard index AM; but perhaps some extension behaves that way.

- Silence bogus missing contrecord errors (Thomas Munro) §

  Treat this case as plain end-of-WAL to avoid logging inaccurate complaints from pg_waldump and walsender.

- Fix overly strict assertion in `jsonpath` code (David Rowley) §

  This assertion failed if a query applied the `.type()` operator to a `like_regex` result. There was no bug in non-assert builds.

- Avoid assertion failure when processing an empty statement via the extended query protocol in an already-aborted transaction (Tom Lane) §

- Avoid assertion failure when the `stats_fetch_consistency` setting is changed intra-transaction (Kyotaro Horiguchi) §

- Fix `contrib/fuzzystrmatch`'s Soundex `difference()` function to handle empty input sanely (Alexander Lakhin, Tom Lane) §

  An input string containing no alphabetic characters resulted in unpredictable output.

- Tighten whitespace checks in `contrib/hstore` input (Evan Jones) §

  In some cases, characters would be falsely recognized as whitespace and hence discarded.

- Disallow oversize input arrays with `contrib/intarray`'s `gist__int_ops` index opclass (Ankit Kumar Pandey, Alexander Lakhin) §

  Previously this code would report a `NOTICE` but press on anyway, creating an invalid index entry that presents a risk of crashes when the index is read.

- Avoid useless double decompression of GiST index entries in `contrib/intarray` (Konstantin Knizhnik, Matthias van de Meent, Tom Lane) §

- Fix `contrib/pageinspect`'s `gist_page_items()` function to work when there are included index columns (Alexander Lakhin, Michael Paquier) §

  Previously, if the index has included columns, `gist_page_items()` would fail to display those values on index leaf pages, or crash outright on non-leaf pages.

- In psql, ignore the `PSQL_WATCH_PAGER` environment variable when stdin/stdout are not a terminal (Tom Lane) §

  This corresponds to the treatment of `PSQL_PAGER` in commands besides `\watch`.

- Fix pg_dump to correctly handle new-style SQL-language functions whose bodies require parse-time dependencies on unique indexes (Tom Lane) §

  Such cases can arise from `GROUP BY` and `ON CONFLICT` clauses, for example. The function must then be postponed until after the unique index in the dump output, but pg_dump did not do that and instead printed a warning about could not resolve dependency loop.

- Improve pg_dump's display of details about dependency-loop problems (Tom Lane) §

- Avoid crash in pgbench with an empty pipeline and prepared mode (Álvaro Herrera) §

- Ensure that pg_index.indisreplident is kept up-to-date in relation cache entries (Shruthi Gowda) §

  This value could be stale in some cases. There is no core code that relies on the relation cache's copy, so this is only a latent bug as far as Postgres itself is concerned; but there may be extensions for which it is a live bug.

- Fix make_etags script to work with non-Exuberant ctags (Masahiko Sawada) §

## Release 15.3

## Release date:

2023-05-11

This release contains a variety of fixes from 15.2. For information about new features in major release 15, see release-15.

## Migration to Version 15.3

A dump/restore is not required for those running 15.X.

However, if you are upgrading from a version earlier than 15.1, see release-15-1.

## Changes

- Prevent `CREATE SCHEMA` from defeating changes in `search_path` (Alexander Lakhin) § §

  Within a `CREATE SCHEMA` command, objects in the prevailing `search_path`, as well as those in the newly-created schema, would be visible even within a called function or script that attempted to set a secure `search_path`. This could allow any user having permission to create a schema to hijack the privileges of a security definer function or extension script.

  The PostgreSQL Project thanks Alexander Lakhin for reporting this problem. (CVE-2023-2454)

- Enforce row-level security policies correctly after inlining a set-returning function (Stephen Frost, Tom Lane) §

  If a set-returning SQL-language function refers to a table having row-level security policies, and it can be inlined into a calling query, those RLS policies would not get enforced properly in some cases involving re-using a cached plan under a different role. This could allow a user to see or modify rows that should have been invisible.

  The PostgreSQL Project thanks Wolfgang Walther for reporting this problem. (CVE-2023-2455)

- Fix potential corruption of the template (source) database after `CREATE DATABASE` with the `STRATEGY WAL_LOG` option (Nathan Bossart, Ryo Matsumura) §

  Improper buffer handling created a risk that any later modification of the template's pg_class catalog would be lost.

- Fix memory leakage and unnecessary disk reads during `CREATE DATABASE` with the `STRATEGY WAL_LOG` option (Andres Freund) §

- Avoid crash when the new schema name is omitted in `CREATE SCHEMA` (Michael Paquier) §

  The SQL standard allows writing `CREATE SCHEMA AUTHORIZATION `owner_name``, with the schema name defaulting to `owner_name`. However some code paths expected the schema name to be present and would fail.

- Fix various planner failures with `MERGE` commands (Tom Lane) § §

  Planning could fail with errors like variable not found in subplan target list or PlaceHolderVar found where not expected.

- Fix the row count reported by `MERGE` for some corner cases (Dean Rasheed) § §

  The row count reported in the command tag counted rows that actually hadn't been modified due to a `BEFORE ROW` trigger returning NULL. This is inconsistent with what happens in plain `UPDATE` or `DELETE`, so change it to not count such rows. Also, avoid counting a row twice when `MERGE` moves it into a different partition of a partitioned table.

- Fix `MERGE` problems with concurrent updates (Dean Rasheed, Álvaro Herrera) § §

  Some cases misbehaved if a row to be updated or deleted by `MERGE` had just been updated by a concurrent transaction. This could lead to a crash, or the wrong merge action being executed, or no action at all.

- Add support for decompiling `MERGE` commands (Álvaro Herrera) §

  This was overlooked when `MERGE` was added, but it's essential support for `MERGE` in new-style SQL functions.

- Fix enabling/disabling of foreign-key triggers in partitioned tables (Tom Lane) §

  `ALTER TABLE ... ENABLE/DISABLE TRIGGER` failed if applied to a partitioned table's foreign-key enforcement triggers, because it tried to locate the clone triggers for the partitions by name, and they do not have the same name. Locate them by parent-trigger OID instead.

- Disallow altering composite types that are stored in indexes (Tom Lane) §

  `ALTER TYPE` disallows non-binary-compatible modifications of composite types if they are stored in any table columns. (Perhaps that will be allowed someday, but it hasn't happened yet; the locking implications of rewriting many tables are daunting.) We overlooked the possibility that an index might contain a composite type that doesn't also appear in its table.

- Disallow system columns as elements of foreign keys (Tom Lane) §

  Since the removal of OID as a system column, there is no plausible use-case for this, and various bits of code no longer support it. Disallow it rather than trying to fix all the cases.

- Ensure that `COPY TO` from an RLS-enabled parent table does not copy any rows from child tables (Antonin Houska) §

  The documentation is quite clear that `COPY TO` copies rows from only the named table, not any inheritance children it may have. However, if row-level security was enabled on the table then this stopped being true.

- Avoid possible crash when `array_position()` or `array_positions()` is passed an empty array (Tom Lane) §

- Fix possible out-of-bounds fetch in `to_char()` (Tom Lane) §

  With bad luck this could have resulted in a server crash.

- Avoid buffer overread in `translate()` function (Daniil Anisimov) §

  When using the deletion feature, the function might fetch the byte just after the input string, creating a small risk of crash.

- Adjust text-search-related character classification logic to correctly detect whether the prevailing locale is `C` (Jeff Davis) §

  This code got confused if the database's default collation uses ICU.

- Avoid possible crash on empty input for type `interval` (Tom Lane) §

- Re-allow exponential notation in ISO-8601 interval fields (Tom Lane) §

  Interval input like `P0.1e10D` isn't officially sanctioned by ISO-8601, but we accepted it for a long time before version 15, so re-allow it.

- Fix error cursor setting for parse errors in JSON string literals (Tom Lane) §

  Most cases in which a syntax error is detected in a string literal within a JSON value failed to set the error cursor appropriately. This led at least to an unhelpful error message (pointing to the token before the string, rather than the actual trouble spot), and could even result in a crash in v14 and later.

- Fix data corruption due to `vacuum_defer_cleanup_age` being larger than the current 64-bit xid (Andres Freund) §

  In v14 and later with non-default settings of `vacuum_defer_cleanup_age`, it was possible to compute a very large vacuum cleanup horizon xid, leading to vacuum removing rows that are still live. v12 and v13 have a lesser form of the same problem affecting only GiST indexes, which could lead to index pages getting recycled too early.

- Fix parser's failure to detect some cases of improperly-nested aggregates (Tom Lane) §

  This oversight could lead to executor failures for queries that should have been rejected as invalid.

- Fix data structure corruption during parsing of serial `SEQUENCE NAME` options (David Rowley) §

  This can lead to trouble if an event trigger captures the corrupted parse tree.

- Correctly update plan nodes' parallel-safety markings when moving initplans from one node to another (Tom Lane) §

  This planner oversight could lead to subplan was not initialized errors at runtime.

- Avoid failure with PlaceHolderVars in extended-statistics code (Tom Lane) §

  Use of dependency-type extended statistics could fail with PlaceHolderVar found where not expected.

- Fix incorrect tests for whether a qual clause applied to a subquery can be transformed into a window aggregate run condition within the subquery (David Rowley) §

  A SubPlan within such a clause would cause assertion failures or incorrect answers, as would some other unusual cases.

- Disable the inverse-transition optimization for window aggregates when the call contains sub-SELECTs (David Rowley) §

  This optimization requires that the aggregate's argument expressions have repeatable results, which might not hold for a sub-SELECT.

- Fix oversights in execution of nested `ARRAY[]` constructs (Alexander Lakhin, Tom Lane) §

  Correctly detect overflow of the total space needed for the result array, avoiding a possible crash due to undersized output allocation. Also ensure that any trailing padding space in the result array is zeroed; while leaving garbage there is harmless for most purposes, it can result in odd behavior later.

- Prevent crash when updating a field within an array-of-domain-over-composite-type column (Dmitry Dolgov) §

- Fix partition pruning logic for partitioning on boolean columns (David Rowley) §

  Pruning with a condition like `boolcol IS NOT TRUE` was done incorrectly, leading to possibly not returning rows in which `boolcol` is NULL. Also, the rather unlikely case of partitioning on `NOT boolcol` was handled incorrectly.

- Fix race condition in per-batch cleanup during parallel hash join (Thomas Munro, Melanie Plageman) §

  A crash was possible given unlucky timing and `parallel_leader_participation` = `off` (which is not the default).

- Recalculate `GENERATED` columns after an EvalPlanQual check (Tom Lane) §

  In `READ COMMITTED` isolation mode, the effects of a row update might need to get reapplied to a newer version of the row than the query found originally. If so, we need to recompute any `GENERATED` columns, in case they depend on columns that were changed by the concurrent update.

- Fix memory leak in Memoize plan execution (David Rowley) §

- Fix buffer refcount leak when using batched inserts for a foreign table included in a partitioned tree (Alexander Pyhalov) §

- Restore support for sub-millisecond `vacuum_cost_delay` settings (Thomas Munro) §

- Don't balance vacuum cost delay when a table has a per-relation `vacuum_cost_delay` setting of zero (Masahiko Sawada) §

  Delay balancing is supposed to be disabled whenever autovacuum is processing a table with a per-relation `vacuum_cost_delay` setting, but this was done only for positive settings, not zero.

- Fix corner-case crashes when columns have been added to the end of a view (Tom Lane) §

- Repair rare failure of MULTIEXPR_SUBLINK subplans in partitioned updates (Andres Freund, Tom Lane) §

  Use of the syntax `INSERT ... ON CONFLICT DO UPDATE SET (c1, ...) = (SELECT ...)` with a partitioned target table could result in failure if any child table is dissimilar from the parent (for example, different physical column order). This typically manifested as failure of consistency checks in the executor; but a crash or incorrect data updates are also possible.

- Fix handling of `DEFAULT` markers within a multi-row `INSERT ... VALUES` query on a view that has a `DO ALSO INSERT ... SELECT` rule (Dean Rasheed) §

  Such cases typically failed with unrecognized node type errors or assertion failures.

- Support references to `OLD` and `NEW` within subqueries in rule actions (Dean Rasheed, Tom Lane) §

  Such references are really lateral references, but the server could crash if the subquery wasn't explicitly marked with `LATERAL`. Arrange to do that implicitly when necessary.

- When decompiling a rule or SQL function body containing `INSERT`/`UPDATE`/`DELETE` within `WITH`, take care to print the correct alias for the target table (Tom Lane) §

- Fix glitches in `SERIALIZABLE READ ONLY` optimization (Thomas Munro) § §

  Transactions already marked as doomed confused the safe-snapshot optimization for `SERIALIZABLE READ ONLY` transactions. The optimization was unnecessarily skipped in some cases. In other cases an assertion failure occurred (but there was no problem in non-assert builds).

- Avoid leaking cache callback slots in the `pgoutput` logical decoding plugin (Shi Yu) §

  Multiple cycles of starting up and shutting down the plugin within a single session would eventually lead to an out of relcache_callback_list slots error.

- Avoid unnecessary calls to custom validators for index operator class options (Alexander Korotkov) §

  This change fixes some cases where an unexpected error was thrown.

- Avoid useless work while scanning a multi-column BRIN index with multiple scan keys (Tomas Vondra) §

  The existing code effectively considered only the last scan key while deciding whether a range matched, thus usually scanning more of the index than it needed to.

- Fix netmask handling in BRIN inet_minmax_multi_ops opclass (Tomas Vondra) §

  This error triggered an assertion failure in assert-enabled builds, but is mostly harmless in production builds.

- Fix dereference of dangling pointer during buffering build of a GiST index (Alexander Lakhin) §

  This error seems to usually be harmless in production builds, as the fetched value is noncritical; but in principle it could cause a server crash.

- Ignore dropped columns and generated columns during logical replication of an update or delete action (Onder Kalaci, Shi Yu) § §

  Replication with the `REPLICA IDENTITY FULL` option failed if the table contained such columns.

- Correct the name of the wait event for SLRU buffer I/O for commit timestamps (Alexander Lakhin) §

  This wait event is named `CommitTsBuffer` according to the documentation, but the code had it as `CommitTSBuffer`. Change the code to match the documentation, as that way is more consistent with the naming of related wait events.

- Re-activate reporting of wait event `SLRUFlushSync` (Thomas Munro) §

  Reporting of this type of wait was accidentally removed in code refactoring.

- Avoid possible underflow when calculating how many WAL segments to keep (Kyotaro Horiguchi) §

  This could result in not honoring `wal_keep_size` accurately.

- Disable startup progress reporting overhead in standby mode (Bharath Rupireddy) §

  In standby mode, we don't actually report progress of recovery, but we were doing work to track it anyway.

- Support RSA-PSS certificates with SCRAM-SHA-256 channel binding (Jacob Champion, Heikki Linnakangas) §

  This feature requires building with OpenSSL 1.1.1 or newer. Both the server and libpq are affected.

- Avoid race condition with process ID tracking on Windows (Thomas Munro) § § §

  The operating system could recycle a PID before the postmaster observed that that child process was gone. This could lead to tracking more than one child with the same PID, resulting in confusion.

- Fix `list_copy_head()` to work correctly on an empty List (David Rowley) §

  This case is not known to be reached by any core PostgreSQL code, but extensions might rely on it working.

- Add missing cases to `SPI_result_code_string()` (Dean Rasheed) §

- Fix erroneous Valgrind markings in `AllocSetRealloc()` (Karina Litskevich) §

  In the unusual case where the size of a large (>8kB) palloc chunk is decreased, a Valgrind-aware build would mismark the defined-ness state of the memory released from the chunk, possibly causing incorrect results during Valgrind testing.

- Fix assertion failure for `MERGE` into a partitioned table with row-level security enabled (Dean Rasheed) §

- Avoid assertion failure when decoding a transactional logical replication message (Tomas Vondra) §

- Avoid locale sensitivity when processing regular expression escapes (Jeff Davis) §

  A backslash followed by a non-ASCII character could sometimes cause an assertion failure, depending on the prevailing locale.

- Avoid trying to write an empty WAL record in `log_newpage_range()` when the last few pages in the specified range are empty (Matthias van de Meent) §

  It is not entirely clear whether this case is reachable in released branches, but if it is then an assertion failure could occur.

- Fix session-lifespan memory leakage in plpgsql `DO` blocks that use cast expressions (Ajit Awekar, Tom Lane) §

- Tighten array dimensionality checks when converting Perl list structures to multi-dimensional SQL arrays (Tom Lane) §

  plperl could misbehave when the nesting of sub-lists is inconsistent so that the data does not represent a rectangular array of values. Such cases now produce errors, but previously they could result in a crash or garbage output.

- Tighten array dimensionality checks when converting Python list structures to multi-dimensional SQL arrays (Tom Lane) § §

  plpython could misbehave when dealing with empty sub-lists, or when the nesting of sub-lists is inconsistent so that the data does not represent a rectangular array of values. The former should result in an empty output array, and the latter in an error. But some cases resulted in a crash, and others in unexpected output.

- Fix unwinding of exception stack in plpython (Xing Guo) §

  Some rare failure cases could return without cleaning up the PG_TRY exception stack, risking a crash if another error was raised before the next stack level was unwound.

- Fix inconsistent GSS-encryption error handling in libpq's `PQconnectPoll()` (Michael Paquier) §

  With `gssencmode` set to `require`, the connection was not marked dead after a GSS initialization failure. Make it fail immediately, as the equivalent case for TLS encryption has long done.

- Fix possible data corruption in ecpg programs built with the `-C ORACLE` option (Kyotaro Horiguchi) §

  When `ecpg_get_data()` is called with `varcharsize` set to zero, it could write a terminating zero character into the last byte of the preceding field, truncating the data in that field.

- Fix pg_dump so that partitioned tables that are hash-partitioned on an enum-type column can be restored successfully (Tom Lane) §

  Since the hash codes for enum values depend on the OIDs assigned to the enum, they are typically different after a dump and restore, meaning that rows often need to go into a different partition than they were in originally. Users can work around that by specifying the `--load-via-partition-root` option; but since there is very little chance of success without that, teach pg_dump to apply it automatically to such tables.

  Also, fix pg_restore to not try to `TRUNCATE` target tables before restoring into them when `--load-via-partition-root` mode is used. This avoids a hazard of deadlocks and lost data.

- Correctly detect non-seekable files on Windows (Juan José Santamaría Flecha, Michael Paquier, Daniel Watzinger) § §

  This bug led to misbehavior when pg_dump writes to a pipe or pg_restore reads from one.

- In pgbench's prepared mode, prepare all the commands in a pipeline before starting the pipeline (Álvaro Herrera) §

  This avoids a failure when a pgbench script tries to start a serializable transaction inside a pipeline.

- In `contrib/amcheck`'s heap checking code, deal correctly with tuples having zero xmin or xmax (Robert Haas) § §

- In `contrib/amcheck`, deal sanely with xids that appear to be before epoch zero (Andres Freund) §

  In cases of corruption we might see a wrapped-around 32-bit xid that appears to be before the first xid epoch. Promoting such a value to 64-bit form produced a value far in the future, resulting in wrong reports. Return FirstNormalFullTransactionId in such cases so that things work reasonably sanely.

- In `contrib/basebackup_to_shell`, properly detect failure to open a pipe (Robert Haas) §

- In `contrib/hstore_plpython`, avoid crashing if the Python value to be transformed isn't a mapping (Dmitry Dolgov, Tom Lane) §

  This should give an error, but Python 3 changed some APIs in a way that caused the check to misbehave, allowing a crash to ensue.

- Require the `siglen` option of a GiST index on an `ltree` column, if specified, to be a multiple of 4 (Alexander Korotkov) §

  Other values result in misaligned accesses to index content, which is harmless on Intel-compatible hardware but can cause a crash on some other architectures.

- In `contrib/pageinspect`, add defenses against incorrect input for the `gist_page_items()` function (Dmitry Koval) §

- Fix misbehavior in `contrib/pg_trgm` with an unsatisfiable regular expression (Tom Lane) §

  A regex such as `$foo` is legal but unsatisfiable; the regex compiler recognizes that and produces an empty NFA graph. Attempting to optimize such a graph into a pg_trgm GIN or GiST index qualification resulted in accessing off the end of a work array, possibly leading to crashes.

- Fix handling of escape sequences in `contrib/postgres_fdw`'s `application_name` parameter (Kyotaro Horiguchi, Michael Paquier) §

  The code to expand these could fail if executed in a background process, as for example during auto-analyze of a foreign table.

- In `contrib/pg_walinspect`, limit memory usage of `pg_get_wal_records_info()` (Bharath Rupireddy) §

- Use the `--strip-unneeded` option when stripping static libraries with GNU-compatible strip (Tom Lane) §

  Previously, `make install-strip` used the `-x` option in this case. This change avoids misbehavior of llvm-strip, and gives slightly smaller output as well.

- Stop recommending auto-download of DTD files for building the documentation, and indeed disable it (Aleksander Alekseev, Peter Eisentraut, Tom Lane) §

  It appears no longer possible to build the SGML documentation without a local installation of the DocBook DTD files. Formerly xsltproc could download those files on-the-fly from sourceforge.net; but sourceforge.net now permits only HTTPS access, and no common version of xsltproc supports that. Hence, remove the bits of our documentation suggesting that that's possible or useful, and instead add xsltproc's `--nonet` option to the build recipes.

- When running TAP tests in PGXS builds, use a saner location for the temporary `portlock` directory (Peter Eisentraut) §

  Place it under `tmp_check` in the build directory. With the previous coding, a PGXS build would try to place it in the installation directory, which is not necessarily writable.

- Update time zone data files to tzdata release 2023c for DST law changes in Egypt, Greenland, Morocco, and Palestine. (Tom Lane) §

  When observing Moscow time, Europe/Kirov and Europe/Volgograd now use the abbreviations MSK/MSD instead of numeric abbreviations, for consistency with other timezones observing Moscow time. Also, America/Yellowknife is no longer distinct from America/Edmonton; this affects some pre-1948 timestamps in that area.

## Release 15.2

## Release date:

2023-02-09

This release contains a variety of fixes from 15.1. For information about new features in major release 15, see release-15.

## Migration to Version 15.2

A dump/restore is not required for those running 15.X.

However, if you are upgrading from a version earlier than 15.1, see release-15-1.

## Changes

- libpq can leak memory contents after GSSAPI transport encryption initiation fails (Jacob Champion) §

  A modified server, or an unauthenticated man-in-the-middle, can send a not-zero-terminated error message during setup of GSSAPI (Kerberos) transport encryption. libpq will then copy that string, as well as following bytes in application memory up to the next zero byte, to its error report. Depending on what the calling application does with the error report, this could result in disclosure of application memory contents. There is also a small probability of a crash due to reading beyond the end of memory. Fix by properly zero-terminating the server message. (CVE-2022-41862)

- Fix calculation of which `GENERATED` columns need to be updated in child tables during an `UPDATE` on a partitioned table or inheritance tree (Amit Langote, Tom Lane) § §

  This fixes failure to update `GENERATED` columns that do not exist in the parent table, or that have different dependencies than are in the parent column's generation expression.

- Fix possible failure of `MERGE` to compute `GENERATED` columns (Dean Rasheed) §

  When the first row-level action of the `MERGE` was an `UPDATE`, any subsequent `INSERT` actions would fail to compute `GENERATED` columns that were deemed unnecessary to compute for the `UPDATE` action (due to not depending on any of the `UPDATE` target columns).

- Fix `MERGE`'s check for unreachable `WHEN` clauses (Dean Rasheed) §

  A `WHEN` clause following an unconditional `WHEN` clause should be rejected as unreachable, but this case was not always detected.

- Fix `MERGE`'s rule-detection test (Dean Rasheed) §

  `MERGE` is not supported on tables with rules; but it also failed on tables that once had rules but no longer do.

- In `MERGE`, don't count a `DO NOTHING` action as a processed tuple (Álvaro Herrera) §

  This makes the code's behavior match the documentation.

- Allow a `WITH RECURSIVE ... CYCLE` CTE to access its output column (Tom Lane) §

  A reference to the `SET` column from within the CTE would fail with cache lookup failed for type 0.

- Fix handling of pending inserts when doing a bulk insertion to a foreign table (Etsuro Fujita) § §

  In some cases pending insertions were not flushed to the FDW soon enough, leading to logical inconsistencies, for example `BEFORE ROW` triggers not seeing rows they should be able to see.

- Allow `REPLICA IDENTITY` to be set on an index that's not (yet) valid (Tom Lane) §

  When pg_dump dumps a partitioned index that's marked `REPLICA IDENTITY`, it generates a command sequence that applies `REPLICA IDENTITY` before the partitioned index has been marked valid, causing restore to fail. There seems no very good reason to prohibit doing it in that order, so allow it. The marking will have no effect anyway until the index becomes valid.

- Fix handling of `DEFAULT` markers in rules that perform an `INSERT` from a multi-row `VALUES` list (Dean Rasheed) §

  In some cases a `DEFAULT` marker would not get replaced with the proper default-value expression, leading to an unrecognized node type error.

- Reject uses of undefined variables in `jsonpath` existence checks (Alexander Korotkov, David G. Johnston) §

  While `jsonpath` match operators threw an error for an undefined variable in the path pattern, the existence operators silently treated it as a match.

- Fix `jsonb` subscripting to cope with toasted subscript values (Tom Lane, David G. Johnston) §

  Using a text value fetched directly from a table as a `jsonb` subscript was likely to fail. Fetches would usually not find any matching element. Assignments could store the value with a garbage key, although keys long enough to cause that problem are probably rare in the field.

- Fix edge-case data corruption in parallel hash joins (Dmitry Astapov) §

  If the final chunk of a large tuple being written out to a temporary file was exactly 32760 bytes, it would be corrupted due to a fencepost bug. The query would typically fail later with corrupted-data symptoms.

- Honor non-default settings of `checkpoint_completion_target` (Bharath Rupireddy) §

  Internal state was not updated after a change in `checkpoint_completion_target`, possibly resulting in performing checkpoint I/O faster or slower than desired, especially if that setting was changed on-the-fly.

- Log the correct ending timestamp in `recovery_target_xid` mode (Tom Lane) §

  When ending recovery based on the `recovery_target_xid` setting with `recovery_target_inclusive` = `off`, we printed an incorrect timestamp (always 2000-01-01) in the recovery stopping before ... transaction log message.

- Improve error reporting for some buffered file read failures (Peter Eisentraut) §

  Correctly report a short read, giving the numbers of bytes desired and actually read, instead of reporting an irrelevant error code. Most places got this right already, but some recently-written replication logic did not.

- Remove arbitrary limit on number of elements in `int2vector` and `oidvector` (Tom Lane) §

  The input functions for these types previously rejected more than 100 elements. With the introduction of the logical replication column list feature, it's necessary to accept `int2vector`s having up to 1600 columns, otherwise long column lists cause logical-replication failures.

- In extended query protocol, avoid an immediate commit after `ANALYZE` if we're running a pipeline (Tom Lane) §

  If there's not been an explicit `BEGIN TRANSACTION`, `ANALYZE` would take it on itself to commit, which should not happen within a pipelined series of commands.

- Reject cancel request packets having the wrong length (Andrey Borodin) §

  The server would process a cancel request even if its length word was too small. This led to reading beyond the end of the allocated buffer. In theory that could cause a segfault, but it seems quite unlikely to happen in practice, since the buffer would have to be very close to the end of memory. The more likely outcome was a bogus log message about wrong backend PID or cancel code. Complain about the wrong length, instead.

- Fix planner preprocessing oversights for window function run-condition expressions (Richard Guo, David Rowley) §

  This could lead to planner errors such as WindowFunc not found in subplan target lists.

- Fix possible dangling-pointer access during execution of window function run-condition expressions (David Rowley) §

  In practice, because the run-condition optimization is only applied to certain window functions that happen to all return `int8`, this only manifested as a problem on 32-bit builds.

- Add recursion and looping defenses in subquery pullup (Tom Lane) §

  A contrived query can result in deep recursion and unreasonable amounts of time spent trying to flatten subqueries. A proper fix for that seems unduly invasive for a back-patch, but we can at least add stack depth checks and an interrupt check to allow the query to be cancelled.

- Fix planner issues when combining Memoize nodes with partitionwise joins or parameterized nestloops (Richard Guo) § §

  These errors could lead to not using Memoize in contexts where it would be useful, or possibly to wrong query plans.

- Fix partitionwise-join code to tolerate failure to produce a plan for each partition (Tom Lane) §

  This could result in could not devise a query plan for the given query errors.

- Limit the amount of cleanup work done by `get_actual_variable_range` (Simon Riggs) §

  Planner runs occurring just after deletion of a large number of tuples appearing at the end of an index could expend significant amounts of work setting the killed bits for those index entries. Limit the amount of work done in any one query by giving up on this process after examining 100 heap pages. All the cleanup will still happen eventually, but without so large a performance hiccup.

- Prevent the statistics machinery from getting confused when a relation's relkind changes (Andres Freund) §

  Converting a table to a view could lead to crashes or assertion failures.

- Fix under-parenthesized display of `AT TIME ZONE` constructs (Tom Lane) §

  This could result in dump/restore failures for rules or views in which an argument of `AT TIME ZONE` is itself an expression.

- Prevent clobbering of cached parsetrees for utility statements in SQL functions (Tom Lane, Daniel Gustafsson) §

  If a SQL-language function executes the same utility command more than once within a single calling query, it could crash or report strange errors such as unrecognized node type.

- Ensure that execution of full-text-search queries can be cancelled while they are performing phrase matches (Tom Lane) §

- Fix memory leak in hashing strings with nondeterministic collations (Jeff Davis) §

- Fix deadlock between `DROP DATABASE` and logical replication worker process (Hou Zhijie) §

  This was caused by an ill-advised choice to block interrupts while creating a logical replication slot in the worker. In version 15 that could lead to an undetected deadlock. In version 14, no deadlock has been observed, but it's still a bad idea to block interrupts while waiting for network I/O.

- Clean up the libpq connection object after a failed replication connection attempt (Andres Freund) §

  The previous coding leaked the connection object. In background code paths that's pretty harmless because the calling process will give up and exit. But in commands such as `CREATE SUBSCRIPTION`, such a failure resulted in a small session-lifespan memory leak.

- In hot-standby servers, reduce processing effort for tracking XIDs known to be active on the primary (Simon Riggs, Michail Nikolaev) §

  Insufficiently-aggressive cleanup of the KnownAssignedXids array could lead to poor performance, particularly when `max_connections` is set to a large value on the standby.

- Ignore invalidated logical-replication slots while determining oldest catalog xmin (Sirisha Chamarthi) §

  A replication slot could prevent cleanup of dead tuples in the system catalogs even after it becomes invalidated due to exceeding `max_slot_wal_keep_size`. Thus, failure of a replication consumer could lead to indefinitely-large catalog bloat.

- In logical decoding, notify the remote node when a transaction is detected to have crashed (Hou Zhijie) §

  After a server restart, we'll re-stream the changes for transactions occurring shortly before the restart. Some of these transactions probably never completed; when we realize that one didn't we throw away the relevant decoding state locally, but we neglected to tell the subscriber about it. That led to the subscriber keeping useless streaming files until it's next restarted.

- Fix uninitialized-memory usage in logical decoding (Masahiko Sawada) §

  In certain cases, resumption of logical decoding could try to re-use XID data that had already been freed, leading to unpredictable behavior.

- Acquire spinlock while updating shared state during logical decoding context creation (Masahiko Sawada) §

  We neglected to acquire the appropriate lock while updating data about two-phase transactions, potentially allowing other processes to see inconsistent data.

- Fix pgoutput replication plug-in to not send columns not listed in a table's replication column list (Hou Zhijie) §

  `UPDATE` and `DELETE` events did not pay attention to the configured column list, thus sending more data than expected. This did not cause a problem when the receiver is our built-in logical replication code, but it might confuse other receivers, and in any case it wasted network bandwidth.

- Avoid rare failed to acquire cleanup lock panic during WAL replay of hash-index page split operations (Robert Haas) §

- Advance a heap page's LSN when setting its all-visible bit during WAL replay (Jeff Davis) §

  Failure to do this left the page possibly different on standby servers than the primary, and violated some other expectations about when the LSN changes. This seems only a theoretical hazard so far as PostgreSQL itself is concerned, but it could upset third-party tools.

- Fix `int64_div_fast_to_numeric()` to work for a wider range of inputs (Dean Rasheed) §

  This function misbehaved with some values of its second argument. No such usages exist in core PostgreSQL, but it's clearly a hazard for external modules, so repair.

- Fix latent buffer-overrun problem in `WaitEventSet` logic (Thomas Munro) §

  The `epoll`-based and `kqueue`-based implementations could ask the kernel for too many events if the size of their internal buffer was different from the size of the caller's output buffer. That case is not known to occur in released PostgreSQL versions, but this error is a hazard for external modules and future bug fixes.

- Avoid nominally-undefined behavior when accessing shared memory in 32-bit builds (Andres Freund) §

  clang's undefined-behavior sanitizer complained about use of a pointer that was less aligned than it should be. It's very unlikely that this would cause a problem in non-debug builds, but it's worth fixing for testing purposes.

- Fix assertion failure in BRIN minmax-multi opclasses (Tomas Vondra) §

  The assertion was overly strict, so this mistake was harmless in non-assert builds.

- Remove faulty assertion in useless-RESULT-RTE optimization logic (Tom Lane) §

- Fix copy-and-paste errors in cache-lookup-failure messages for ACL checks (Justin Pryzby) §

  In principle these errors should never be reached. But if they are, some of them reported the wrong type of object.

- Fix possible corruption of very large tablespace map files in pg_basebackup (Antonin Houska) §

- Avoid harmless warning from pg_dump in `--if-exists` mode (Tom Lane) §

  If the `public` schema has a non-default owner then use of pg_dump's `--if-exists` option resulted in a warning message warning: could not find where to insert IF EXISTS in statement "-- *not* dropping schema, since initdb creates it". The dump output was okay, though.

- Fix psql's `\sf` and `\ef` commands to handle SQL-language functions that have SQL-standard function bodies (Tom Lane) §

  These commands misidentified the start of the function body when it used new-style syntax.

- Fix tab completion of `ALTER FUNCTION/PROCEDURE/ROUTINE` ... `SET SCHEMA` (Dean Rasheed) §

- Update `contrib/pageinspect` to mark its disk-accessing functions as `PARALLEL RESTRICTED` (Tom Lane) §

  This avoids possible failure if one of these functions is used to examine a temporary table, since a session's temporary tables are not accessible from parallel workers.

- Fix `contrib/seg` to not crash or print garbage if an input number has more than 127 digits (Tom Lane) §

- Fix build on Microsoft Visual Studio 2013 (Tom Lane) §

  A previous patch supposed that all platforms of interest have `snprintf()`, but MSVC 2013 isn't quite there yet. Revert to using `sprintf()` on that platform.

- Fix compile failure in building PL/Perl with MSVC when using Strawberry Perl (Andrew Dunstan) §

- Fix mismatch of PL/Perl built with MSVC versus a Perl library built with gcc (Andrew Dunstan) §

  Such combinations could previously fail with loadable library and perl binaries are mismatched errors.

- Suppress compiler warnings from Perl's header files (Andres Freund) §

  Our preferred compiler options provoke warnings about constructs appearing in recent versions of Perl's header files. When using gcc, we can suppress these warnings with a pragma.

- Fix pg_waldump to build on compilers that don't discard unused static-inline functions (Tom Lane) §

- Update time zone data files to tzdata release 2022g for DST law changes in Greenland and Mexico, plus historical corrections for northern Canada, Colombia, and Singapore. (Tom Lane) §

  Notably, a new timezone America/Ciudad_Juarez has been split off from America/Ojinaga.

## Release 15.1

## Release date:

2022-11-10

This release contains a variety of fixes from 15.0. For information about new features in major release 15, see release-15.

## Migration to Version 15.1

A dump/restore is not required for those running 15.X.

However, if you regularly create and drop tables exceeding 1GB, see the first changelog entry below.

## Changes

- Fix failure to remove non-first segments of large tables (Tom Lane) §

  PostgreSQL splits large tables into multiple files (normally with 1GB per file). The logic for dropping a table was broken and would miss removing all but the first such file, in two cases: drops of temporary tables and WAL replay of drops of regular tables. Applications that routinely create multi-gigabyte temporary tables could suffer significant disk space leakage.

  Orphaned temporary-table files are removed during postmaster start, so the mere act of updating to 15.1 is sufficient to clear any leaked temporary-table storage. However, if you suffered any database crashes while using 15.0, and there might have been large tables dropped just before such crashes, it's advisable to check the database directories for files named according to the pattern ``NNNN`.`NN``. If there is no matching file named just ``NNNN`` (without the `.`NN`` suffix), these files should be removed manually.

- Fix handling of `DEFAULT` tokens that appear in a multi-row `VALUES` clause of an `INSERT` on an updatable view (Tom Lane) §

  This oversight could lead to cache lookup failed for type errors, or in older branches even to crashes.

- Disallow rules named `_RETURN` that are not `ON SELECT` (Tom Lane) §

  This avoids confusion between a view's `ON SELECT` rule and any other rules it may have.

- Avoid failure in `EXPLAIN VERBOSE` for a query using `SEARCH BREADTH FIRST` with constant initial values (Tom Lane) §

- Prevent use of `MERGE` on a partitioned table with foreign-table partitions (Álvaro Herrera) §

  The case isn't supported, and previously threw an incomprehensible error.

- Fix construction of per-partition foreign key constraints while doing `ALTER TABLE ATTACH PARTITION` (Jehan-Guillaume de Rorthais, Álvaro Herrera) § §

  Previously, incorrect or duplicate constraints could be constructed for the newly-added partition.

- Fix planner failure with extended statistics on partitioned or inherited tables (Richard Guo, Justin Pryzby) §

  Some cases failed with cache lookup failed for statistics object.

- Fix mis-ordering of WAL operations in fast insert path for GIN indexes (Matthias van de Meent, Zhang Mingli) §

  This mistake is not known to have any negative consequences within core PostgreSQL, but it did cause issues for some extensions.

- Fix bugs in logical decoding when replay starts from a point between the beginning of a transaction and the beginning of its subtransaction (Masahiko Sawada, Kuroda Hayato) § §

  These errors could lead to assertion failures in debug builds, and otherwise to memory leaks.

- Accept interrupts in more places during logical decoding (Amit Kapila, Masahiko Sawada) § §

  This ameliorates problems with slow shutdown of replication workers.

- Prevent attempts to replicate into a foreign-table partition in replication workers (Shi Yu, Tom Lane) §

  Although partitioned tables can have foreign tables as partitions, replicating into such a partition isn't currently supported. The logical replication worker process would crash if it was attempted. Now, an error is thrown.

- Avoid crash after function syntax error in replication workers (Maxim Orlov, Anton Melnikov, Masahiko Sawada, Tom Lane) §

  If a syntax error occurred in a SQL-language or PL/pgSQL-language `CREATE FUNCTION` or `DO` command executed in a logical replication worker, the worker process would crash with a null pointer dereference or assertion failure.

- Avoid double call of the shutdown callback of an archiver module (Nathan Bossart, Bharath Rupireddy) §

- Add plan-time check for attempted access to a table that has no table access method (Tom Lane) §

  This prevents a crash in some catalog-corruption scenarios, for example use of a view whose `ON SELECT` rule is missing.

- Prevent postmaster crash when shared-memory state is corrupted (Tom Lane) §

  The postmaster process is supposed to survive and initiate a database restart if shared memory becomes corrupted, but one bit of code was being insufficiently cautious about that.

- In libpq, handle single-row mode correctly when pipelining (Denis Laxalde) §

  The single-row flag was not reset at the correct time if pipeline mode was also active.

- Fix psql's exit status when a command-line query is canceled (Peter Eisentraut) §

  `psql -c `query`` would exit successfully if the query was canceled. Fix it to exit with nonzero status, as in other error cases.

- Allow cross-platform tablespace relocation in pg_basebackup (Robert Haas) §

  Allow the remote path in `--tablespace-mapping` to be either a Unix-style or Windows-style absolute path, since the source server could be on a different OS than the local system.

- Fix pg_dump's failure to dump comments attached to some `CHECK` constraints (Tom Lane) §

- Fix `CREATE DATABASE` to allow its `oid` parameter to exceed 231 (Tom Lane) §

  This oversight prevented pg_upgrade from succeeding when the source installation contained databases with OIDs larger than that.

- In pg_stat_statements, fix access to already-freed memory (zhaoqigui) §

  This occurred if pg_stat_statements tracked a `ROLLBACK` command issued via extended query protocol. In debug builds it consistently led to an assertion failure. In production builds there would often be no visible ill effect; but if the freed memory had already been reused, the likely result would be to store garbage for the query string.

- Fix incompatibilities with LLVM 15 (Thomas Munro, Andres Freund) §

- Allow use of `__sync_lock_test_and_set()` for spinlocks on any machine (Tom Lane) §

  This eases porting to new machine architectures, at least if you're using a compiler that supports this GCC builtin function.

- Rename symbol `REF` to `REF_P` to avoid compile failure on recent macOS (Tom Lane) §

- Avoid using `sprintf`, to avoid compile-time deprecation warnings (Tom Lane) §

- Update time zone data files to tzdata release 2022f for DST law changes in Chile, Fiji, Iran, Jordan, Mexico, Palestine, and Syria, plus historical corrections for Chile, Crimea, Iran, and Mexico. (Tom Lane) §

  Also, the Europe/Kiev zone has been renamed to Europe/Kyiv. Also, the following zones have been merged into nearby, more-populous zones whose clocks have agreed with them since 1970: Antarctica/Vostok, Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik, Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg, Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas, Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion, Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei, Pacific/Wake and Pacific/Wallis. (This indirectly affects zones that were already links to one of these: Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape, Pacific/Truk, and Pacific/Yap.) America/Nipigon, America/Rainy_River, America/Thunder_Bay, Europe/Uzhgorod, and Europe/Zaporozhye were also merged into nearby zones after discovering that their claimed post-1970 differences from those zones seem to have been errors. In all these cases, the previous zone name remains as an alias; but the actual data is that of the zone that was merged into.

  These zone mergers result in loss of pre-1970 timezone history for the merged zones, which may be troublesome for applications expecting consistency of `timestamptz` display. As an example, the stored value `1944-06-01 12:00 UTC` would previously display as `1944-06-01 13:00:00+01` if the Europe/Stockholm zone is selected, but now it will read out as `1944-06-01 14:00:00+02`.

  It is possible to build the time zone data files with options that will restore the older zone data, but that choice also inserts a lot of other old (and typically poorly-attested) zone data, resulting in more total changes from the previous release than accepting these upstream changes does. PostgreSQL has chosen to ship the tzdb data as-recommended, and so far as we are aware most major operating system distributions are doing likewise. However, if these changes cause significant problems for your application, a possible solution is to install a local build of the time zone data files using tzdb's backwards-compatibility options (see their `PACKRATDATA` and `PACKRATLIST` options).

## Release 15

## Release date:

2022-10-13

## Overview

PostgreSQL 15 contains many new features and enhancements, including:

- Support for the SQL `MERGE` command.

- Selective publication of tables' contents within logical replication publications, through the ability to specify column lists and row filter conditions.

- More options for compression, including support for Zstandard (zstd) compression. This includes support for performing compression on the server side during pg_basebackup.

- Support for structured server log output using the JSON format.

- Performance improvements, particularly for in-memory and on-disk sorting.

The above items and other new features of PostgreSQL 15 are explained in more detail in the sections below.

## Migration to Version 15

A dump/restore using app-pg-dumpall or use of pgupgrade or logical replication is required for those wishing to migrate data from any previous release. See upgrading for general information on migrating to new major releases.

Version 15 contains a number of changes that may affect compatibility with previous releases. Observe the following incompatibilities:

- Remove `PUBLIC` creation permission on the `public` schema (Noah Misch) §

  The new default is one of the secure schema usage patterns that ddl-schemas-patterns has recommended since the security release for CVE-2018-1058. The change applies to new database clusters and to newly-created databases in existing clusters. Upgrading a cluster or restoring a database dump will preserve `public`'s existing permissions.

  For existing databases, especially those having multiple users, consider revoking `CREATE` permission on the `public` schema to adopt this new default. For new databases having no need to defend against insider threats, granting `CREATE` permission will yield the behavior of prior releases.

- Change the owner of the `public` schema to be the new `pg_database_owner` role (Noah Misch) §

  This allows each database's owner to have ownership privileges on the `public` schema within their database. Previously it was owned by the bootstrap superuser, so that non-superuser database owners could not do anything with it.

  This change applies to new database clusters and to newly-created databases in existing clusters. Upgrading a cluster or restoring a database dump will preserve `public`'s existing ownership specification.

- Remove long-deprecated exclusive backup mode (David Steele, Nathan Bossart) §

  If the database server stops abruptly while in this mode, the server could fail to start. The non-exclusive backup mode is considered superior for all purposes. Functions `pg_start_backup()`/`pg_stop_backup()` have been renamed to `pg_backup_start()`/`pg_backup_stop()`, and the functions `pg_backup_start_time()` and `pg_is_in_backup()` have been removed.

- Increase `hash_mem_multiplier` default to 2.0 (Peter Geoghegan) §

  This allows query hash operations to use more `work_mem` memory than other operations.

- Remove server-side language `plpython2u` and generic Python language `plpythonu` (Andres Freund) §

  Python 2.x is no longer supported. While the original intent of `plpythonu` was that it could eventually refer to `plpython3u`, changing it now seems more likely to cause problems than solve them, so it's just been removed.

- Generate an error if `array_to_tsvector()` is passed an empty-string array element (Jean-Christophe Arnu) §

  This is prohibited because lexemes should never be empty. Users of previous Postgres releases should verify that no empty lexemes are stored because they can lead to dump/restore failures and inconsistent results.

- Generate an error when `chr()` is supplied with a negative argument (Peter Eisentraut) §

- Prevent `CREATE OR REPLACE VIEW` from changing the collation of an output column (Tom Lane) §

- Disallow zero-length Unicode identifiers, e.g., `U&""` (Peter Eisentraut) §

  Non-Unicode zero-length identifiers were already disallowed.

- Prevent numeric literals from having non-numeric trailing characters (Peter Eisentraut) §

  Previously, query text like `123abc` would be interpreted as `123` followed by a separate token `abc`.

- Adjust JSON numeric literal processing to match the SQL/JSON-standard (Peter Eisentraut) §

  This accepts numeric formats like `.1` and `1.`, and disallows trailing junk after numeric literals, like `1.type()`.

- When `interval` input provides a fractional value for a unit greater than months, round to the nearest month (Bruce Momjian) §

  For example, convert `1.99 years` to `2 years`, not `1 year 11 months` as before.

- Improve consistency of `interval` parsing with trailing periods (Tom Lane) §

  Numbers with trailing periods were rejected on some platforms.

- Mark the `interval` output function as stable, not immutable, since it depends on `IntervalStyle` (Tom Lane) §

  This will, for example, cause creation of indexes relying on the text output of `interval` values to fail.

- Detect integer overflow in interval justification functions (Joe Koshakow) §

  The affected functions are `justify_interval()`, `justify_hours()`, and `justify_days()`.

- Change the I/O format of type `"char"` for non-ASCII characters (Tom Lane) §

  Bytes with the high bit set are now output as a backslash and three octal digits, to avoid encoding issues.

- Remove the default `ADMIN OPTION` privilege a login role has on its own role membership (Robert Haas) §

  Previously, a login role could add/remove members of its own role, even without `ADMIN OPTION` privilege.

- Allow logical replication to run as the owner of the subscription (Mark Dilger) §

  Because row-level security policies are not checked, only superusers, roles with `bypassrls`, and table owners can replicate into tables with row-level security policies.

- Prevent `UPDATE` and `DELETE` logical replication operations on tables where the subscription owner does not have `SELECT` permission on the table (Jeff Davis) §

  `UPDATE` and `DELETE` commands typically involve reading the table as well, so require the subscription owner to have table `SELECT` permission.

- When `EXPLAIN` references the session's temporary object schema, refer to it as `pg_temp` (Amul Sul) §

  Previously the actual schema name was reported, leading to inconsistencies across sessions.

- Fix pg_statio_all_tables to sum values for the rare case of TOAST tables with multiple indexes (Andrei Zubkov) §

  Previously such cases would show one row for each index.

- Disallow setting custom options that match the name of an installed extension, but are not one of the extension's declared variables (Florin Irion, Tom Lane) § § §

  This change causes any such pre-existing variables to be deleted during extension load, and then prevents new ones from being created later in the session. The intent is to prevent confusion about whether a variable is associated with an extension or not.

- Remove obsolete server variable `stats_temp_directory` (Andres Freund, Kyotaro Horiguchi) §

- Improve the algorithm used to compute `random()` (Fabien Coelho) § §

  This will cause `random()`'s results to differ from what was emitted by prior versions, even for the same seed value.

- libpq's `PQsendQuery()` function is no longer supported in pipeline mode (Álvaro Herrera) §

  Applications that are using that combination will need to be modified to use `PQsendQueryParams()` instead.

- On non-Windows platforms, consult the `HOME` environment variable to find the user's home directory (Anders Kaseorg) §

  If `HOME` is empty or unset, fall back to the previous method of checking the `<pwd.h>` database. This change affects libpq (for example, while looking up `~/.pgpass`) as well as various client application programs.

- Remove pg_dump's `--no-synchronized-snapshots` option (Tom Lane) §

  All still-supported server versions support synchronized snapshots, so there's no longer a need for this option.

- After an error is detected in psql's `--single-transaction` mode, change the final `COMMIT` command to `ROLLBACK` only if `ON_ERROR_STOP` is set (Michael Paquier) §

- Avoid unnecessary casting of constants in queries sent by postgres_fdw (Dian Fay) §

  When column types are intentionally different between local and remote databases, such casts could cause errors.

- Remove xml2's `xml_is_well_formed()` function (Tom Lane) §

  This function has been implemented in the core backend since Postgres 9.1.

- Allow custom scan providers to indicate if they support projections (Sven Klemm) §

  The default is now that custom scan providers are assumed to not support projections; those that do will need to be updated for this release.

## Changes

Below you will find a detailed account of the changes between PostgreSQL 15 and the previous major release.

### Server

- Record and check the collation version of each database (Peter Eisentraut) §

  This feature is designed to detect collation version changes to avoid index corruption. Function `pg_database_collation_actual_version()` reports the underlying operating system collation version, and `ALTER DATABASE ... REFRESH` sets the recorded database collation version to match the operating system collation version.

- Allow ICU collations to be set as the default for clusters and databases (Peter Eisentraut) §

  Previously, only libc-based collations could be selected at the cluster and database levels. ICU collations could only be used via explicit `COLLATE` clauses.

- Add system view pg_ident_file_mappings to report `pg_ident.conf` information (Julien Rouhaud) §

#### Partitioning

- Improve planning time for queries referencing partitioned tables (David Rowley) §

  This change helps when only a few of many partitions are relevant.

- Allow ordered scans of partitions to avoid sorting in more cases (David Rowley) §

  Previously, a partitioned table with a `DEFAULT` partition or a `LIST` partition containing multiple values could not be used for ordered partition scans. Now they can be used if such partitions are pruned during planning.

- Improve foreign key behavior of updates on partitioned tables that move rows between partitions (Amit Langote) §

  Previously, such updates ran a delete action on the source partition and an insert action on the target partition. PostgreSQL will now run an update action on the partition root, providing cleaner semantics.

- Allow `CLUSTER` on partitioned tables (Justin Pryzby) § §

- Fix `ALTER TRIGGER RENAME` on partitioned tables to properly rename triggers on all partitions (Arne Roland, Álvaro Herrera) §

  Also prohibit cloned triggers from being renamed.

#### Indexes

- Allow btree indexes on system and TOAST tables to efficiently store duplicates (Peter Geoghegan) §

  Previously de-duplication was disabled for these types of indexes.

- Improve lookup performance of GiST indexes that were built using sorting (Aliaksandr Kalenik, Sergei Shoulbakov, Andrey Borodin) §

- Allow unique constraints and indexes to treat `NULL` values as not distinct (Peter Eisentraut) §

  Previously `NULL` entries were always treated as distinct values, but this can now be changed by creating constraints and indexes using `UNIQUE NULLS NOT DISTINCT`.

- Allow the `^@` starts-with operator and the `starts_with()` function to use btree indexes if using the C collation (Tom Lane) §

  Previously these could only use SP-GiST indexes.

#### Optimizer

- Allow extended statistics to record statistics for a parent with all its children (Tomas Vondra, Justin Pryzby) §

  Regular statistics already tracked parent and parent-plus-all-children statistics separately.

- Add server variable `recursive_worktable_factor` to allow the user to specify the expected size of the working table of a recursive query (Simon Riggs) §

#### General Performance

- Allow hash lookup for `NOT IN` clauses with many constants (David Rowley, James Coleman) §

  Previously the code always sequentially scanned the list of values.

- Allow `SELECT DISTINCT` to be parallelized (David Rowley) §

- Speed up encoding validation of UTF-8 text by processing 16 bytes at a time (John Naylor, Heikki Linnakangas) §

  This will improve text-heavy operations like `COPY FROM`.

- Improve performance for sorts that exceed `work_mem` (Heikki Linnakangas) § §

  When the sort data no longer fits in `work_mem`, switch to a batch sorting algorithm that uses more output streams than before.

- Improve performance and reduce memory consumption of in-memory sorts (Ronan Dunklau, David Rowley, Thomas Munro, John Naylor) § § §

- Allow WAL full page writes to use LZ4 and Zstandard compression (Andrey Borodin, Justin Pryzby) § §

  This is controlled by the `wal_compression` server setting.

- Add support for writing WAL using direct I/O on macOS (Thomas Munro) §

  This only works if `max_wal_senders = 0` and `wal_level = minimal`.

- Allow vacuum to be more aggressive in setting the oldest frozen and multi transaction id (Peter Geoghegan) §

- Allow a query referencing multiple foreign tables to perform parallel foreign table scans in more cases (Andrey Lepikhov, Etsuro Fujita) §

- Improve the performance of window functions that use `row_number()`, `rank()`, `dense_rank()` and `count()` (David Rowley) §

- Improve the performance of spinlocks on high-core-count ARM64 systems (Geoffrey Blake) §

#### Monitoring

- Enable default logging of checkpoints and slow autovacuum operations (Bharath Rupireddy) §

  This changes the default of `log_checkpoints` to `on` and that of `log_autovacuum_min_duration` to 10 minutes. This will cause even an idle server to generate some log output, which might cause problems on resource-constrained servers without log file rotation. These defaults should be changed in such cases.

- Generate progress messages in the server log during slow server starts (Nitin Jadhav, Robert Haas) § §

  The messages report the cause of the delay. The time interval for notification is controlled by the new server variable `log_startup_progress_interval`.

- Store cumulative statistics system data in shared memory (Kyotaro Horiguchi, Andres Freund, Melanie Plageman) § §

  Previously this data was sent to a statistics collector process via UDP packets, and could only be read by sessions after transferring it via the file system. There is no longer a separate statistics collector process.

- Add additional information to `VACUUM VERBOSE` and autovacuum logging messages (Peter Geoghegan) § § §

- Add `EXPLAIN (BUFFERS)` output for temporary file block I/O (Masahiko Sawada) §

- Allow log output in JSON format (Sehrope Sarkuni, Michael Paquier) §

  The new setting is `log_destination = jsonlog`.

- Allow `pg_stat_reset_single_table_counters()` to reset the counters of relations shared across all databases (Sadhuprasad Patro) §

- Add wait events for local shell commands (Fujii Masao) §

  The new wait events are used when calling `archive_command`, `archive_cleanup_command`, `restore_command` and `recovery_end_command`.

#### Privileges

- Allow table accesses done by a view to optionally be controlled by privileges of the view's caller (Christoph Heiss) §

  Previously, view accesses were always treated as being done by the view's owner. That's still the default.

- Allow members of the `pg_write_server_files` predefined role to perform server-side base backups (Dagfinn Ilmari Mannsåker) §

  Previously only superusers could perform such backups.

- Allow `GRANT` to grant permissions to change individual server variables via `SET` and `ALTER SYSTEM` (Mark Dilger) § §

  The new function `has_parameter_privilege()` reports on this privilege.

- Add predefined role `pg_checkpoint` that allows members to run `CHECKPOINT` (Jeff Davis) § §

  Previously checkpoints could only be run by superusers.

- Allow members of the `pg_read_all_stats` predefined role to access the views pg_backend_memory_contexts and pg_shmem_allocations (Bharath Rupireddy) §

  Previously these views could only be accessed by superusers.

- Allow `GRANT` to grant permissions on `pg_log_backend_memory_contexts()` (Jeff Davis) §

  Previously this function could only be run by superusers.

#### Server Configuration

- Add server variable `shared_memory_size` to report the size of allocated shared memory (Nathan Bossart) § §

- Add server variable `shared_memory_size_in_huge_pages` to report the number of huge memory pages required (Nathan Bossart) § §

  This is only supported on Linux.

- Honor server variable `shared_preload_libraries` in single-user mode (Jeff Davis) §

  This change supports use of `shared_preload_libraries` to load custom access methods and WAL resource managers, which would be essential for database access even in single-user mode.

- On Solaris, make the default setting of `dynamic_shared_memory_type` be `sysv` (Thomas Munro) §

  The previous default choice, `posix`, can result in spurious failures on this platform.

- Allow `postgres -C` to properly report runtime-computed values (Nathan Bossart) §

  Previously runtime-computed values `data_checksums`, `wal_segment_size`, and `data_directory_mode` would report values that would not be accurate on the running server. However, this does not work on a running server.

### Streaming Replication and Recovery

- Add support for LZ4 and Zstandard compression of server-side base backups (Jeevan Ladhe, Robert Haas) § § §

- Run the checkpointer and bgwriter processes during crash recovery (Thomas Munro) §

  This helps to speed up long crash recoveries.

- Allow WAL processing to pre-fetch needed file contents (Thomas Munro) §

  This is controlled by the server variable `recovery_prefetch`.

- Allow archiving via loadable modules (Nathan Bossart) §

  Previously, archiving was only done by calling shell commands. The new server variable `archive_library` can be set to specify a library to be called for archiving.

- No longer require `IDENTIFY_SYSTEM` to be run before `START_REPLICATION` (Jeff Davis) §

#### Logical Replication

- Allow publication of all tables in a schema (Vignesh C, Hou Zhijie, Amit Kapila) § § §

  For example, this syntax is now supported: `CREATE PUBLICATION pub1 FOR TABLES IN SCHEMA s1,s2`. `ALTER PUBLICATION` supports a similar syntax. Tables added later to the listed schemas will also be replicated.

- Allow publication content to be filtered using a `WHERE` clause (Hou Zhijie, Euler Taveira, Peter Smith, Ajin Cherian, Tomas Vondra, Amit Kapila) § § §

  Rows not satisfying the `WHERE` clause are not published.

- Allow publication content to be restricted to specific columns (Tomas Vondra, Álvaro Herrera, Rahila Syed) §

- Allow skipping of transactions on a subscriber using `ALTER SUBSCRIPTION ... SKIP` (Masahiko Sawada) §

- Add support for prepared (two-phase) transactions to logical replication (Peter Smith, Ajin Cherian, Amit Kapila, Nikhil Sontakke, Stas Kelvich) § § §

  The new `CREATE_REPLICATION_SLOT` option is called `TWO_PHASE`. pg_recvlogical now supports a new `--two-phase` option during slot creation.

- Prevent logical replication of empty transactions (Ajin Cherian, Hou Zhijie, Euler Taveira) §

  Previously, publishers would send empty transactions to subscribers if subscribed tables were not modified.

- Add SQL functions to monitor the directory contents of logical replication slots (Bharath Rupireddy) §

  The new functions are `pg_ls_logicalsnapdir()`, `pg_ls_logicalmapdir()`, and `pg_ls_replslotdir()`. They can be run by members of the predefined `pg_monitor` role.

- Allow subscribers to stop the application of logical replication changes on error (Osumi Takamichi, Mark Dilger) §

  This is enabled with the subscriber option `disable_on_error` and avoids possible infinite error loops during stream application.

- Adjust subscriber server variables to match the publisher so datetime and float8 values are interpreted consistently (Japin Li) §

  Some publishers might be relying on inconsistent behavior.

- Add system view pg_stat_subscription_stats to report on subscriber activity (Masahiko Sawada) § §

  The new function `pg_stat_reset_subscription_stats()` allows resetting these statistics counters.

- Suppress duplicate entries in the pg_publication_tables system view (Hou Zhijie) §

  In some cases a partition could appear more than once.

### Utility Commands

- Add SQL `MERGE` command to adjust one table to match another (Simon Riggs, Pavan Deolasee, Álvaro Herrera, Amit Langote) §

  This is similar to `INSERT ... ON CONFLICT` but more batch-oriented.

- Add support for `HEADER` option in `COPY` text format (Rémi Lapeyre) § §

  The new option causes the column names to be output, and optionally verified on input.

- Add new WAL-logged method for database creation (Dilip Kumar) §

  This is the new default method for copying the template database, as it avoids the need for checkpoints during database creation. However, it might be slow if the template database is large, so the old method is still available.

- Allow `CREATE DATABASE` to set the database OID (Shruthi Gowda, Antonin Houska) §

- Prevent `DROP DATABASE`, `DROP TABLESPACE`, and `ALTER DATABASE SET TABLESPACE` from occasionally failing during concurrent use on Windows (Thomas Munro) §

- Allow foreign key `ON DELETE SET` actions to affect only specified columns (Paul Martinez) §

  Previously, all of the columns in the foreign key were always affected.

- Allow `ALTER TABLE` to modify a table's `ACCESS METHOD` (Justin Pryzby, Jeff Davis) §

- Properly call object access hooks when `ALTER TABLE` causes table rewrites (Michael Paquier) §

- Allow creation of unlogged sequences (Peter Eisentraut) §

- Track dependencies on individual columns in the results of functions returning composite types (Tom Lane) §

  Previously, if a view or rule contained a reference to a specific column within the result of a composite-returning function, that was not noted as a dependency; the view or rule was only considered to depend on the composite type as a whole. This meant that dropping the individual column would be allowed, causing problems in later use of the view or rule. The column-level dependency is now also noted, so that dropping such a column will be rejected unless the view is changed or dropped.

### Data Types

- Allow the scale of a `numeric` value to be negative, or greater than its precision (Dean Rasheed, Tom Lane) §

  This allows rounding of values to the left of the decimal point, e.g., `'1234'::numeric(4, -2)` returns 1200.

- Improve overflow detection when casting values to interval (Joe Koshakow) §

- Change the I/O format of type `"char"` for non-ASCII characters (Tom Lane) §

- Update the display width information of modern Unicode characters, like emojis (Jacob Champion) § §

  Also update from Unicode 5.0 to 14.0.0. There is now an automated way to keep Postgres updated with Unicode releases.

### Functions

- Add multirange input to `range_agg()` (Paul Jungwirth) §

- Add `MIN()` and `MAX()` aggregates for the `xid8` data type (Ken Kato) §

- Add regular expression functions for compatibility with other relational systems (Gilles Darold, Tom Lane) §

  The new functions are `regexp_count()`, `regexp_instr()`, `regexp_like()`, and `regexp_substr()`. Some new optional arguments were also added to `regexp_replace()`.

- Add the ability to compute the distance between `polygons` (Tom Lane) §

- Add `to_char()` format codes `of`, `tzh`, and `tzm` (Nitin Jadhav) §

  The upper-case equivalents of these were already supported.

- When applying `AT TIME ZONE` to a `time with time zone` value, use the transaction start time rather than wall clock time to determine whether DST applies (Aleksander Alekseev, Tom Lane) §

  This allows the conversion to be considered stable rather than volatile, and it saves a kernel call per invocation.

- Ignore NULL array elements in `ts_delete()` and `setweight()` functions with array arguments (Jean-Christophe Arnu) §

  These functions effectively ignore empty-string array elements (since those could never match a valid lexeme). It seems consistent to let them ignore NULL elements too, instead of failing.

- Add support for petabyte units to `pg_size_pretty()` and `pg_size_bytes()` (David Christensen) §

- Change `pg_event_trigger_ddl_commands()` to output references to other sessions' temporary schemas using the actual schema name (Tom Lane) §

  Previously this function reported all temporary schemas as `pg_temp`, but it's misleading to use that for any but the current session's temporary schema.

### PL/pgSQL

- Fix enforcement of PL/pgSQL variable `CONSTANT` markings (Tom Lane) §

  Previously, a variable could be used as a `CALL` output parameter or refcursor `OPEN` variable despite being marked `CONSTANT`.

### libpq

- Allow IP address matching against a server certificate's Subject Alternative Name (Jacob Champion) §

- Allow `PQsslAttribute()` to report the SSL library type without requiring a libpq connection (Jacob Champion) §

- Change query cancellations sent by the client to use the same TCP settings as normal client connections (Jelte Fennema) §

  This allows configured TCP timeouts to apply to query cancel connections.

- Prevent libpq event callback failures from forcing an error result (Tom Lane) § §

### Client Applications

- Allow pgbench to retry after serialization and deadlock failures (Yugo Nagata, Marina Polyakova) §

#### app-psql

- Improve performance of psql's `\copy` command, by sending data in larger chunks (Heikki Linnakangas) §

- Add `\dconfig` command to report server variables (Mark Dilger, Tom Lane) § § §

  This is similar to the server-side `SHOW` command, but it can process patterns to show multiple variables conveniently.

- Add `\getenv` command to assign the value of an environment variable to a psql variable (Tom Lane) §

- Add `+` option to the `\lo_list` and `\dl` commands to show large-object privileges (Pavel Luzanov) §

- Add a pager option for the `\watch` command (Pavel Stehule, Thomas Munro) §

  This is only supported on Unix and is controlled by the `PSQL_WATCH_PAGER` environment variable.

- Make psql include intra-query double-hyphen comments in queries sent to the server (Tom Lane, Greg Nancarrow) § §

  Previously such comments were removed from the query before being sent. Double-hyphen comments that are before any query text are not sent, and are not recorded as separate psql history entries.

- Adjust psql so that Readline's meta-`#` command will insert a double-hyphen comment marker (Tom Lane) §

  Previously a pound marker was inserted, unless the user had taken the trouble to configure a non-default comment marker.

- Make psql output all results when multiple queries are passed to the server at once (Fabien Coelho) §

  Previously, only the last query result was displayed. The old behavior can be restored by setting the `SHOW_ALL_RESULTS` psql variable to `off`.

- After an error is detected in `--single-transaction` mode, change the final `COMMIT` command to `ROLLBACK` only if `ON_ERROR_STOP` is set (Michael Paquier) §

  Previously, detection of an error in a `-c` command or `-f` script file would lead to issuing `ROLLBACK` at the end, regardless of the value of `ON_ERROR_STOP`.

- Improve psql's tab completion (Shinya Kato, Dagfinn Ilmari Mannsåker, Peter Smith, Koyu Tanigawa, Ken Kato, David Fetter, Haiying Tang, Peter Eisentraut, Álvaro Herrera, Tom Lane, Masahiko Sawada) § § § § § § § § § § § § § § § § § § § §

- Limit support of psql's backslash commands to servers running PostgreSQL 9.2 or later (Tom Lane) §

  Remove code that was only used when running with an older server. Commands that do not require any version-specific adjustments compared to 9.2 will still work.

#### pg_dump

- Make pg_dump dump `public` schema ownership changes and security labels (Noah Misch) § §

- Improve performance of dumping databases with many objects (Tom Lane) § § §

  This will also improve the performance of pg_upgrade.

- Improve parallel pg_dump's performance for tables with large TOAST tables (Tom Lane) §

- Add dump/restore option `--no-table-access-method` to force restore to only use the default table access method (Justin Pryzby) §

- Limit support of pg_dump and pg_dumpall to servers running PostgreSQL 9.2 or later (Tom Lane) §

### Server Applications

- Add new pg_basebackup option `--target` to control the base backup location (Robert Haas) §

  The new options are `server` to write the backup locally and `blackhole` to discard the backup (for testing).

- Allow pg_basebackup to do server-side gzip, LZ4, and Zstandard compression and client-side LZ4 and Zstandard compression of base backup files (Dipesh Pandit, Jeevan Ladhe) § § §

  Client-side `gzip` compression was already supported.

- Allow pg_basebackup to compress on the server side and decompress on the client side before storage (Dipesh Pandit) §

  This is accomplished by specifying compression on the server side and plain output format.

- Allow pg_basebackup's `--compress` option to control the compression location (server or client), compression method, and compression options (Michael Paquier, Robert Haas) § § §

- Add the LZ4 compression method to pg_receivewal (Georgios Kokolatos) § §

  This is enabled via `--compress=lz4` and requires binaries to be built using `--with-lz4`.

- Add additional capabilities to pg_receivewal's `--compress` option (Georgios Kokolatos) §

- Improve pg_receivewal's ability to restart at the proper WAL location (Ronan Dunklau) §

  Previously, pg_receivewal would start based on the WAL file stored in the local archive directory, or at the sending server's current WAL flush location. With this change, if the sending server is running Postgres 15 or later, the local archive directory is empty, and a replication slot is specified, the replication slot's restart point will be used.

- Add pg_rewind option `--config-file` to simplify use when server configuration files are stored outside the data directory (Gunnar Bluth) §

#### pg_upgrade

- Store pg_upgrade's log and temporary files in a subdirectory of the new cluster called `pg_upgrade_output.d` (Justin Pryzby) § § §

  Previously such files were left in the current directory, requiring manual cleanup. Now they are automatically removed on successful completion of pg_upgrade.

- Disable default status reporting during pg_upgrade operation if the output is not a terminal (Andres Freund) §

  The status reporting output can be enabled for non-tty usage by using `--verbose`.

- Make pg_upgrade report all databases with invalid connection settings (Jeevan Ladhe) §

  Previously only the first database with an invalid connection setting was reported.

- Make pg_upgrade preserve tablespace and database OIDs, as well as relation relfilenode numbers (Shruthi Gowda, Antonin Houska) § § §

- Add a `--no-sync` option to pg_upgrade (Michael Paquier) §

  This is recommended only for testing.

- Limit support of pg_upgrade to old servers running PostgreSQL 9.2 or later (Tom Lane) §

#### pg_waldump

- Allow pg_waldump output to be filtered by relation file node, block number, fork number, and full page images (David Christensen, Thomas Munro) § §

- Make pg_waldump report statistics before an interrupted exit (Bharath Rupireddy) §

  For example, issuing a control-C in a terminal running `pg_waldump --stats --follow` will report the current statistics before exiting. This does not work on Windows.

- Improve descriptions of some transaction WAL records reported by pg_waldump (Masahiko Sawada, Michael Paquier) §

- Allow pg_waldump to dump information about multiple resource managers (Heikki Linnakangas) §

  This is enabled by specifying the `--rmgr` option multiple times.

### Documentation

- Add documentation for `pg_encoding_to_char()` and `pg_char_to_encoding()` (Ian Lawrence Barwick) §

- Document the `^@` starts-with operator (Tom Lane) §

### Source Code

- Add support for continuous integration testing using cirrus-ci (Andres Freund, Thomas Munro, Melanie Plageman) §

- Add configure option `--with-zstd` to enable Zstandard builds (Jeevan Ladhe, Robert Haas, Michael Paquier) §

- Add an ABI identifier field to the magic block in loadable libraries, allowing non-community PostgreSQL distributions to identify libraries that are not compatible with other builds (Peter Eisentraut) §

  An ABI field mismatch will generate an error at load time.

- Create a new pg_type.typcategory value for `"char"` (Tom Lane) §

  Some other internal-use-only types have also been assigned to this category.

- Add new protocol message `TARGET` to specify a new `COPY` method to be used for base backups (Robert Haas) §

  pg_basebackup now uses this method.

- Add new protocol message `COMPRESSION` and `COMPRESSION_DETAIL` to specify the compression method and options (Robert Haas) § §

- Remove server support for old `BASE_BACKUP` command syntax and base backup protocol (Robert Haas) § §

- Add support for extensions to set custom backup targets (Robert Haas) §

- Allow extensions to define custom WAL resource managers (Jeff Davis) §

- Add function `pg_settings_get_flags()` to get the flags of server variables (Justin Pryzby) §

- On Windows, export all the server's global variables using `PGDLLIMPORT` markers (Robert Haas) §

  Previously, only specific variables were accessible to extensions on Windows.

- Require GNU make version 3.81 or later to build PostgreSQL (Tom Lane) §

- Require OpenSSL to build the pgcrypto extension (Peter Eisentraut) §

- Require Perl version 5.8.3 or later (Dagfinn Ilmari Mannsåker) §

- Require Python version 3.2 or later (Andres Freund) §

### Additional Modules

- Allow amcheck to check sequences (Mark Dilger) §

- Improve amcheck sanity checks for TOAST tables (Mark Dilger) §

- Add new module basebackup_to_shell as an example of a custom backup target (Robert Haas) § §

- Add new module basic_archive as an example of performing archiving via a library (Nathan Bossart) §

- Allow btree_gist indexes on boolean columns (Emre Hasegeli) § § §

  These can be used for exclusion constraints.

- Fix pageinspect's `page_header()` to handle 32-kilobyte page sizes (Quan Zongliang) §

  Previously, improper negative values could be returned in certain cases.

- Add counters for temporary file block I/O to pg_stat_statements (Masahiko Sawada) §

- Add JIT counters to pg_stat_statements (Magnus Hagander) §

- Add new module pg_walinspect (Bharath Rupireddy) §

  This gives SQL-level output similar to pg_waldump.

- Indicate the permissive/enforcing state in sepgsql log messages (Dave Page) §

#### postgres_fdw

- Allow postgres_fdw to push down `CASE` expressions (Alexander Pyhalov) §

- Add server variable `postgres_fdw.application_name` to control the application name of postgres_fdw connections (Hayato Kuroda) § § §

  Previously the remote session's `application_name` could only be set on the remote server or via a postgres_fdw connection specification. `postgres_fdw.application_name` supports some escape sequences for customization, making it easier to tell such connections apart on the remote server.

- Allow parallel commit on postgres_fdw servers (Etsuro Fujita) §

  This is enabled with the `CREATE SERVER` option `parallel_commit`.

## Acknowledgments

The following individuals (in alphabetical order) have contributed to this release as patch authors, committers, reviewers, testers, or reporters of issues.

- Abhijit Menon-Sen
- Adam Brusselback
- Adam Mackler
- Adrian Ho
- Ahsan Hadi
- Ajin Cherian
- Alastair McKinley
- Aleksander Alekseev
- Ales Zeleny
- Alex Kingsborough
- Alex Kozhemyakin
- Alexander Korotkov
- Alexander Kukushkin
- Alexander Lakhin
- Alexander Nawratil
- Alexander Pyhalov
- Alexey Borzov
- Alexey Ermakov
- Aliaksandr Kalenik
- Álvaro Herrera
- Amit Kapila
- Amit Khandekar
- Amit Langote
- Amul Sul
- Anastasia Lubennikova
- Anders Kaseorg
- Andreas Dijkman
- Andreas Grob
- Andreas Seltenreich
- Andrei Zubkov
- Andres Freund
- Andrew Alsup
- Andrew Bille
- Andrew Dunstan
- Andrew Gierth
- Andrew Kesper
- Andrey Borodin
- Andrey Lepikhov
- Andrey Sokolov
- Andy Fan
- Anton Melnikov
- Anton Voloshin
- Antonin Houska
- Arjan van de Ven
- Arne Roland
- Arthur Zakirov
- Ashutosh Bapat
- Ashutosh Sharma
- Ashwin Agrawal
- Asif Rehman
- Asim Praveen
- Atsushi Torikoshi
- Aya Iwata
- Bauyrzhan Sakhariyev
- Benoit Lobréau
- Bernd Dorn
- Bertrand Drouvot
- Bharath Rupireddy
- Björn Harrtell
- Boris Kolpackov
- Boris Korzun
- Brad Nicholson
- Brar Piening
- Bruce Momjian
- Bruno da Silva
- Bryn Llewellyn
- Carl Sopchak
- Cary Huang
- Chapman Flack
- Chen Jiaoqian
- Chris Bandy
- Chris Lowder
- Christian Quest
- Christoph Berg
- Christoph Heiss
- Christophe Pettus
- Christopher Painter-Wakefield
- Claudio Freire
- Clemens Zeidler
- Corey Huinker
- Dag Lem
- Dagfinn Ilmari Mannsåker
- Dan Kubb
- Daniel Cherniy
- Daniel Gustafsson
- Daniel Polski
- Daniel Vérité
- Daniel Westermann
- Daniele Varrazzo
- Daniil Anisimov
- Danny Shemesh
- Darafei Praliaskouski
- Daria Lepikhova
- Dave Cramer
- Dave Page
- David Christensen
- David Fetter
- David G. Johnston
- David Rowley
- David Steele
- David Zhang
- Dean Rasheed
- Dian Fay
- Dilip Kumar
- Dipesh Pandit
- Dmitry Dolgov
- Dmitry Koval
- Dmitry Marakasov
- Dominique Devienne
- Dong Wook
- Drew DeVault
- Eduard Català
- Egor Chindyaskin
- Egor Rogov
- Ekaterina Kiryanova
- Elena Indrupskaya
- Elvis Pranskevichus
- Emmanuel Quincerot
- Emre Hasegeli
- Eric Mutta
- Erica Zhang
- Erik Rijkers
- Erki Eessaar
- Etsuro Fujita
- Euler Taveira
- Fabien Coelho
- Fabrice Chapuis
- Fabrice Fontaine
- Fabrízio de Royes Mello
- Feike Steenbergen
- Filip Gospodinov
- Florin Irion
- Floris Van Nee
- Frédéric Yhuel
- Gabriela Serventi
- Gaurab Dey
- Geoff Winkless
- Geoffrey Blake
- Georgios Kokolatos
- Gilles Darold
- Greg Nancarrow
- Greg Rychlewski
- Greg Sabino Mullane
- Greg Stark
- Gregory Smith
- Guillaume Lelarge
- Gunnar Bluth
- Gurjeet Singh
- Haiyang Wang
- Haiying Tang
- Hannu Krosing
- Hans Buschmann
- Hayato Kuroda
- Heath Lord
- Heikki Linnakangas
- Herwig Goemans
- Himanshu Upadhyaya
- Holly Roberts
- Hou Zhijie
- Hubert Lubaczewski
- Ian Barwick
- Ian Campbell
- Ibrar Ahmed
- Ildus Kurbangaliev
- Ilya Anfimov
- Itamar Gafni
- Jacob Champion
- Jaime Casanova
- Jakub Wartak
- James Coleman
- James Hilliard
- James Inform
- Jan Piotrowski
- Japin Li
- Jason Harvey
- Jason Kim
- Jean-Christophe Arnu
- Jeevan Ladhe
- Jeff Davis
- Jeff Janes
- Jehan-Guillaume de Rorthais
- Jelte Fennema
- Jeremy Evans
- Jeremy Schneider
- Jian Guo
- Jian He
- Jimmy Yih
- Jiri Fejfar
- Jitka Plesníková
- Joe Conway
- Joe Wildish
- Joel Jacobson
- Joey Bodoia
- John Naylor
- Jonathan Katz
- Josef Simanek
- Joseph Koshakow
- Josh Soref
- Joshua Brindle
- Juan José Santamaría Flecha
- Julien Rouhaud
- Julien Roze
- Junwang Zhao
- Jürgen Purtz
- Justin Pryzby
- Ken Kato
- Kevin Burke
- Kevin Grittner
- Kevin Humphreys
- Kevin McKibbin
- Kevin Sweet
- Kevin Zheng
- Klaudie Willis
- Konstantin Knizhnik
- Konstantina Skovola
- Kosei Masumura
- Kotaro Kawamoto
- Koyu Tanigawa
- Kuntal Ghosh
- Kyotaro Horiguchi
- Lars Kanis
- Lauren Fliksteen
- Laurent Hasson
- Laurenz Albe
- Leslie Lemaire
- Liam Bowen
- Lingjie Qiang
- Liu Huailing
- Louis Jachiet
- Lukas Fittl
- Ma Liangzhu
- Maciek Sakrejda
- Magnus Hagander
- Mahendra Singh Thalor
- Maksim Milyutin
- Marc Bachmann
- Marcin Krupowicz
- Marcus Gartner
- Marek Szuba
- Marina Polyakova
- Mario Emmenlauer
- Mark Dilger
- Mark Murawski
- Mark Wong
- Markus Wanner
- Markus Winand
- Martijn van Oosterhout
- Martin Jurca
- Martin Kalcher
- Martín Marqués
- Masahiko Sawada
- Masahiro Ikeda
- Masao Fujii
- Masaya Kawamoto
- Masayuki Hirose
- Matthias van de Meent
- Matthijs van der Vleuten
- Maxim Orlov
- Maxim Yablokov
- Melanie Plageman
- Michael Banck
- Michael Harris
- Michael J. Sullivan
- Michael Meskes
- Michael Mühlbeyer
- Michael Paquier
- Michael Powers
- Mike Fiedler
- Mike Oh
- Mikhail Kulagin
- Miles Delahunty
- Naoki Okano
- Nathan Bossart
- Nathan Long
- Nazir Bilal Yavuz
- Neha Sharma
- Neil Chen
- Nicola Contu
- Nicolas Lutic
- Nikhil Benesch
- Nikhil Shetty
- Nikhil Sontakke
- Nikita Glukhov
- Nikolai Berkoff
- Nikolay Samokhvalov
- Nikolay Shaplov
- Nitin Jadhav
- Noah Misch
- Noboru Saito
- Noriyoshi Shinoda
- Olaf Bohlen
- Olly Betts
- Onder Kalaci
- Oskar Stenberg
- Otto Kekalainen
- Paul Guo
- Paul Jungwirth
- Paul Martinez
- Pavan Deolasee
- Pavel Borisov
- Pavel Luzanov
- Pavel Stehule
- Peter Eisentraut
- Peter Geoghegan
- Peter Slavov
- Peter Smith
- Petr Jelínek
- Phil Florent
- Phil Krylov
- Pierre-Aurélien Georges
- Prabhat Sahu
- Quan Zongliang
- Rachel Heaton
- Rahila Syed
- Rajakavitha Kodhandapani
- Rajkumar Raghuwanshi
- Ranier Vilela
- Rei Kamigishi
- Reid Thompson
- Rémi Lapeyre
- Renan Soares Lopes
- Richard Guo
- Richard Wesley
- RKN Sai Krishna
- Robert Haas
- Robert Treat
- Roberto Mello
- Robins Tharakan
- Roger Mason
- Roman Zharkov
- Ronan Dunklau
- Rui Zhao
- Ryan Kelly
- Ryo Matsumura
- Ryohei Takahashi
- Sadhuprasad Patro
- Sait Talha Nisanci
- Sami Imseih
- Sandeep Thakkar
- Sebastian Kemper
- Sehrope Sarkuni
- Sergei Kornilov
- Sergei Shoulbakov
- Sergey Shinderuk
- Shay Rojansky
- Shenhao Wang
- Shi Yu
- Shinya Kato
- Shruthi Gowda
- Simon Perepelitsa
- Simon Riggs
- Sirisha Chamarthi
- Soumyadeep Chakraborty
- Stan Hu
- Stas Kelvich
- Stefen Hillman
- Stephen Frost
- Steve Chavez
- Sumanta Mukherjee
- Suraj Khamkar
- Suraj Kharage
- Sven Klemm
- Takamichi Osumi
- Takayuki Tsunakawa
- Takeshi Ideriha
- Tatsuhiro Nakamori
- Tatsuhito Kasahara
- Tatsuo Ishii
- Tatsuro Yamada
- Teja Mupparti
- Teodor Sigaev
- Thibaud Walkowiak
- Thom Brown
- Thomas McKay
- Thomas Munro
- Tim McNamara
- Timo Stolz
- Timur Khanjanov
- Tom Lane
- Tomas Barton
- Tomas Vondra
- Tony Reix
- Troy Frericks
- Tushar Ahuja
- Victor Wagner
- Victor Yegorov
- Vignesh C
- Vik Fearing
- Vincas Dargis
- Vitaly Burovoy
- Vitaly Voronov
- Vladimir Sitnikov
- Wang Ke
- Wei Sun
- Wei Wang
- Whale Song
- Will Mortensen
- Wolfgang Walther
- Yanliang Lei
- Yaoguang Chen
- Yogendra Suralkar
- YoungHwan Joo
- Yugo Nagata
- Yukun Wang
- Yura Sokolov
- Yusuke Egashira
- Yuzuko Hosoya
- Zhang Mingli
- Zhang Wenjie
- Zhihong Yu
- Zhiyong Wu