# Release 18.6

## Release date:

2026-08-13

This release contains a variety of fixes from 18.4. For information about new features in major release 18, see release-18.

Note: 18.5 was never released, due to a regression discovered post-wrap.

## Migration to Version 18.6

A dump/restore is not required for those running 18.X.

However, the first three security entries below describe configuration adjustments and data cleanups that you may need to make after updating.

Also, if you have any GIN indexes, see the changelog entry below about possibly-corrupt reltuples values for their tables.

Also, if you use `contrib/btree_gist` or `contrib/ltree`, you may need to reindex indexes made with those extensions; see the relevant entries below.

Also, if you are upgrading from a version earlier than 18.2, see release-18-2.

## Changes

- Restrict logical decoding output plugins to the set specified by a new server parameter `output_plugin_libraries` (Jacob Champion) § §

  Previously, a replication user could select any loadable library for logical decoding, allowing exploits of various sorts. To allow locking this down without breaking setups that worked before, introduce a whitelist of allowed output plugins.

  By default, only the output plugins shipped as part of PostgreSQL (`pgoutput` and `test_decoding`) are included in `output_plugin_libraries`. Installations that rely on other output plugins must add them after updating the server, for example

      output_plugin_libraries = 'pgoutput, test_decoding, my_trusted_decoder'

  Additionally, `pg_upgrade --check` will fail if the `output_plugin_libraries` parameter on the new cluster does not permit the plugins of logical replication slots on the old cluster, when migrating from versions 17 and later. Make necessary additions to the new cluster's setting before performing pg_upgrade.

  The PostgreSQL Project thanks Vladimir Tokarev and Yu Kunpeng for reporting this problem. (CVE-2026-6471)

- Fix `contrib/pgcrypto`'s PGP encryption to detect unsupported ciphers (Daniel Gustafsson) § §

  Previously, if OpenSSL rejected the requested cipher (for example, because it is running in FIPS mode, or the legacy provider hasn't been loaded), pgcrypto failed to notice the failure and simply XOR'd the non-encrypted block with the plaintext, rendering the encryption trivially breakable. This will typically occur with deprecated or non-FIPS cipher algorithms (cipher-algo=blowfish/bf, twofish, cast5, or 3des).

  By default, pgcrypto will now fail to decrypt any messages that were affected in this way. To allow retrieval of such data, a new option `ignore-cipher-failure` has been added to `pgp_pub_decrypt()` and `pgp_sym_decrypt()`. Setting `ignore-cipher-failure=1` will restore their previous behavior, allowing the faulty encryption wrapper to be stripped off:

      pgp_sym_decrypt(encrypted_column, any key, 'ignore-cipher-failure=1')

  Once the affected messages are identified and stripped of their wrappers, they can then be re-encrypted with a modern algorithm. It is important however that the behavior of OpenSSL be the same as it was when the faulty messages were created: if the set of unsupported algorithms is not the same, this approach will not work. See the documentation for `ignore-cipher-failure`.

  The PostgreSQL Project thanks Shishir Sharma for reporting this problem. (CVE-2026-14663)

- Fix psql to skip in-line data following a scripted `COPY ... FROM STDIN` command, even if the `COPY` fails before sending `PGRES_COPY_IN` (Tom Lane) § §

  Previously, if a `COPY` command failed at startup (for instance, because the target table doesn't exist) psql would not realize that and would proceed to read the following in-line data as SQL commands. In the best case that's wrong and in the worst case it's a SQL-injection hazard. Teach psql to recognize syntactically-valid `COPY ... FROM STDIN` commands and to skip data on its own authority if the server doesn't respond with `PGRES_COPY_IN`.

  While this fix is unlikely to affect any production SQL scripts, test scripts might intentionally exercise failing `COPY ... FROM STDIN` commands. Those will need to gain a `\.` data terminator line after each such command.

  The PostgreSQL Project thanks Alexander Lakhin for reporting this problem. (CVE-2026-6464)

- Cross-check the output row type of a portal running `EXECUTE` or `FETCH` (Robert Haas) §

  `EXECUTE` and `FETCH` use two portals: an outer one for the statement itself, and an inner one running the query being executed on its behalf. It was previously possible to make the declared row types of the two portals diverge, leading to server memory disclosure and arbitrary code execution.

  The PostgreSQL Project thanks Ben Morris (in collaboration with Claude and Anthropic Research) and Peter Geoghegan for reporting this problem. (CVE-2026-16239)

- Fix buffer overrun with long time zone abbreviation in `to_char()` (Tom Lane) §

  This can easily crash the server, and exploits leading to arbitrary code execution have been reported.

  The PostgreSQL Project thanks Hcamael, Amjad Shahzad, Tan Zhen of AntAISecurityLab, Tomer Fichman, Zheng Yu, Amy Burnett (OpenAI Codex Security), Rick de Jager, Heewon Song, Sylvie Mayer, Aleksander Alekseev, and Hillai Ben Sasson for reporting this problem. (CVE-2026-14669)

- Fix buffer overrun in regexp match/split functions (Masahiko Sawada) §

  If passed invalidly-encoded data, these functions could write past the end of their conversion buffer.

  The PostgreSQL Project thanks Francesco Verardi for reporting this problem. (CVE-2026-14664)

- Harden the `ascii()` function against invalid input (Michael Paquier) §

  By supplying invalidly-encoded input, this function could be coaxed to read and return a few bytes of data that it shouldn't. In assert-enabled builds, its assertions could be triggered too.

  The PostgreSQL Project thanks Hcamael for reporting this problem. (CVE-2026-18024)

- Fix multirange type handling in `pg_restore_attribute_stats()` (OpenAI Security Research Team) § §

  `pg_restore_attribute_stats()` treated multirange types just like their underlying range type. This works correctly for the bounds histogram, but it was wrong for all the other statistics kinds.

  The PostgreSQL Project thanks Amy Burnett (OpenAI Codex Security) for reporting this problem. (CVE-2026-16238)

- Make `scalarineqsel()` check that a constant it expects to be of type `tid` actually is (Tom Lane) §

  This expectation will hold for all the built-in operators that use this estimator, but a maliciously-constructed operator could violate it, leading to a crash or server memory disclosure.

  The PostgreSQL Project thanks Hcamael for reporting this problem. (CVE-2026-14668)

- Harden `tsvector` and `tsquery` code against overly long values (both individual lexemes and total vector/query length) (Tom Lane) § §

  The documented limits were not enforced in all code paths.

  The PostgreSQL Project thanks Yuhang Wu, Zhenpeng Lin, Zheng Yu, and Hcamael for reporting these problems. (CVE-2026-14662)

- Fix various places that mistakenly assumed they would not have to deal with more than `FUNC_MAX_ARGS` function arguments (Tom Lane) § §

  Notably, the server's actual limit on the number of arguments to an aggregate function is `FUNC_MAX_ARGS - 1`, but the parser failed to enforce that, creating hazards downstream.

  The PostgreSQL Project thanks Zheng Yu, ylwangtju, and Masahiko Sawada for reporting these problems. (CVE-2026-14679)

- Reject calls from SQL to functions that take or return type `internal` (Tom Lane) § §

  The existing defenses against doing this have been shown to be insufficient, so add more explicit checks.

  The PostgreSQL Project thanks Amy Burnett (OpenAI Codex Security) for reporting this problem. (CVE-2026-14680)

- Preserve the ownership of extended statistics objects when they are rebuilt by `ALTER TABLE` (Masahiko Sawada) §

  Previously, the role running `ALTER TABLE` gained ownership of such objects, but that seems inappropriate.

  The PostgreSQL Project thanks Noah Misch for reporting this problem. (CVE-2026-6469)

- When deparsing an `EXTRACT()` function call, quote the field name if needed (Nathan Bossart) §

  The parser accepts any string literal as a field name in `EXTRACT()`, deferring validation to execution. If the call is stored and deparsed (for example during pg_dump), the string body was regurgitated verbatim, allowing SQL injection.

  The PostgreSQL Project thanks Ben Morris (in collaboration with Claude and Anthropic Research) for reporting this problem. (CVE-2026-15741)

- Check for `USAGE` privilege on data types in places that formerly failed to check that (Nathan Bossart) § § §

  `CREATE TYPE AS RANGE` did not check, nor did `ALTER TABLE OF`, nor did commands that create stored expressions. These omissions allowed roles without `USAGE` privilege to nonetheless create objects depending on the type, possibly blocking the type's owner from changing the type later.

  The PostgreSQL Project thanks Jingzhou Fu for reporting this problem. (CVE-2026-6470)

- Invalidate role-dependent cached plans after role changes (Ilya Staroverov, Shinya Kato, Nathan Bossart) §

  Role membership, role attribute, and database ownership changes may impact the expected behavior of row-level security policies, but previously we'd continue to use cached plans that were made according to the old state of affairs.

  The PostgreSQL Project thanks Ilya Staroverov and Shinya Kato for reporting this problem. (CVE-2026-14666)

- Reject GSSEncRequest after direct SSL connection (Michael Paquier) §

  After establishing a TLS-encrypted connection, the server would still accept a request for GSSAPI encryption. If that succeeded, the connection would proceed using TLS encryption, but it would look like a GSS connection to the `pg_hba` rules. Thus, a `pg_hba` policy intending to disallow TLS would not be enforced correctly.

  The PostgreSQL Project thanks p4p3r for reporting this problem. (CVE-2026-14681)

- Make mock SCRAM authentication secrets more plausible (Nathan Bossart) §

  If a SCRAM login is attempted against a role that doesn't exist or doesn't have a SCRAM secret, we generate a mock secret and carry out the authentication handshake anyway, to avoid revealing these facts to an attacker. But the mock secret was made with a fixed iteration count, which in itself can be an observable response discrepancy. Use the configuration setting `scram_iterations` instead, to make the mock secret look more like the installation's real secrets.

  The PostgreSQL Project thanks Radim Marek for reporting this problem. (CVE-2026-14672)

- Fix out-of-bounds writes in ecpg applications caused by invalid `bytea` data received from the server (Michael Paquier) §

  ecpg assumed without checking that any `bytea` value must begin with `\x`. A broken or malicious server might send a string shorter than 2 bytes, resulting in memory clobber in the application.

  The PostgreSQL Project thanks ylwangtju for reporting this problem. (CVE-2026-16241)

- Do not do backquote expansion on the argument of psql's `\unrestrict` command (Nathan Bossart) §

  This oversight in the fix for CVE-2025-8714 allows a malicious server to inject shell commands into plain-text dump output that will be run at restore time on the machine running psql, the exact scenario that CVE-2025-8714 intended to prevent.

  The PostgreSQL Project thanks Lucas Velgus, Filip Janus, and Daniel Bakker for reporting this problem. (CVE-2026-18408)

- Remove pg_dump's assumption that pg_proc.protrftypes cannot have more than `FUNC_MAX_ARGS` entries (Tom Lane) §

  Since there could be entries for both input and output arguments, it's feasible for this array's length to exceed `FUNC_MAX_ARGS` (which constrains only input arguments). Even if that were not so, pg_dump cannot assume that the server was built with the same value of `FUNC_MAX_ARGS` that it has. An overrun would lead to a memory clobber inside pg_dump.

  The PostgreSQL Project thanks Masahiko Sawada for reporting this problem. (CVE-2026-19385)

- Harden PL/Perl against tied Perl arrays and hashes (Tom Lane) §

  A tied object that doesn't behave like a regular one could lead to memory overwrite, or to constructing a corrupt result array (which would likely cause problems later).

  The PostgreSQL Project thanks Hcamael for reporting this problem. (CVE-2026-14670)

- Fix integer overflows in memory-allocation calculations in PL/Perl and PL/Tcl (Heikki Linnakangas) §

  This is the same type of problem as CVE-2026-6473, just in a different part of the code, and is fixed in the same way.

  The PostgreSQL Project thanks the Tulya Project (Team Dhiutsa, Bitecope Technologies Private Ltd) for reporting this problem. (CVE-2026-14677)

- Ensure that `contrib/amcheck` functions restrict `search_path` before executing index expressions (Noah Misch) §

  Because amcheck will run such index expressions as the owner of their tables, a caller could potentially hijack `search_path`-dependent functions to run arbitrary code as the table owner. By default this is not a vulnerability because only superusers are allowed to call amcheck functions; but if that privilege was granted out, it created a larger hazard than the documentation suggests.

  The PostgreSQL Project thanks Yuelin Wang and Jacob Brazeal for reporting this problem. (CVE-2026-14673)

- Fix integer overflows in `contrib/fuzzystrmatch`'s `levenshtein()` and `levenshtein_less_equal()` functions (Nathan Bossart) §

  Passing large cost values to these functions could cause integer overflows, thereby producing nonsensical results, and even causing out-of-bounds writes in some cases.

  The PostgreSQL Project thanks Ben Morris (in collaboration with Claude and Anthropic Research) for reporting this problem. (CVE-2026-15742)

- Fix buffer overrun in `contrib/pg_stat_statements` (Álvaro Herrera) §

  Query normalization didn't accurately account for the amount of space the normalized string would require.

  The PostgreSQL Project thanks Sajeeb Lohani (with TrendAI Zero Day Initiative) and Yuelin Wang for reporting this problem. (CVE-2026-14676)

- Fix datatype error in `contrib/pg_trgm`'s GiST picksplit function (Heikki Linnakangas) §

  This mistake resulted in reading past the end of the buffer, typically causing bad split decisions; but a crash could ensue if you're very unlucky.

  The PostgreSQL Project thanks Mehmet D. Ince for reporting this problem. (CVE-2026-14678)

- Remove the plan cache in `contrib/refint` (Ayush Tiwari) §

  This caching behavior has several serious bugs, notably that `check_foreign_key()` embeds the new key values in its cascade-UPDATE queries, so a cached plan reuses the originally-needed values rather than the key values that should be used. The simplest solution is to remove it.

  The PostgreSQL Project thanks Hcamael for reporting this problem. (CVE-2026-14671)

- Ensure that parallel GIN index builds update the table's pg_class.reltuples value correctly (Jan Nidzwetzki, Tomas Vondra) §

  A parallel worker could report an uninitialized value for the number of rows it processed, leading to a bogus value for reltuples, even Infinity or NaN. Such values could lead to subsequent autovacuum and autoanalyze operations never deciding that the table needs to be processed. If so, the situation will not self-heal. A manual `ANALYZE` command, or creation of another index, will be needed to reset reltuples to the correct value. If you have any tables with GIN indexes, it's recommended to check to see if their reltuples entries look sane. A query such as this may be helpful:

      SELECT DISTINCT t.oid::regclass, t.reltuples
      FROM pg_class t
        JOIN pg_index i ON t.oid = i.indrelid
        JOIN pg_class ic ON i.indexrelid = ic.oid
      WHERE t.relhasindex AND ic.relam = 2742;

- Fix mis-handling of asynchronous reads when rescanning an asynchronous Append plan node (Alexander Korotkov, Gleb Kashkin, Etsuro Fujita) §

  When an upper plan node rescans an Append before having read the entire Append output, we need to discard any in-flight requests sent to external servers (by `postgres_fdw` for example). This was not done correctly in cases where a subplan has parameter changes or is discarded by partition pruning in the next scan. The outcome could be incorrect query results, an infinite loop, or an assertion failure.

- Fix error in partition pruning for RANGE-partitioned tables (David Rowley) §

  In some cases the DEFAULT partition would be skipped when it should not be, which could lead to rows missing from query results.

- Correctly update foreign-data-wrapper state in a ModifyTable plan node after pruning result relations (Ayush Tiwari, Rafia Sabih) § §

  Previously, if run-time partition pruning determined that some partitions of a partitioned target table need not be scanned and the table had any foreign-table partitions, a crash or erroneous behavior was likely.

- Fix missed concurrent update in `UPDATE` with `RETURNING OLD` on a table that has a `BEFORE UPDATE` trigger (Dean Rasheed) §

  If the target row was concurrently updated, then at isolation level `READ COMMITTED` any `OLD` values in `RETURNING` should reflect the updated row. But stale values were returned if there was a trigger (although the trigger itself, and the final output row, saw the correct values).

- Fix hash join performance issue when there are multiple join keys and many NULL values (David Rowley) §

  Null-keyed tuples should not get inserted into the hash table, since they will never match any other tuples. The code got this wrong if the null was in a non-last join column, bloating the hash table quite a lot if many inputs contain nulls.

- Fix parsing of parenthesized `OLD`/`NEW` in `RETURNING` expressions (Marko Grujic) §

  Expressions such as `(old).colname` and `(old).*` were mis-handled, effectively converting them to `NEW` references.

- Fix planner's nullability and strictness checks for ``value` IN (`array`)` expressions (Ayush Tiwari) §

  These checks should only succeed if the array operand is known to be non-empty, but that consideration was missed, allowing optimizations to be applied that should not be. This could result in wrong query answers if the array actually was empty.

- Fix incorrect join removal logic (Matheus Alcantara, Richard Guo) § §

  In edge cases, it was possible for a constant output value coming from within the nullable side of an outer join to not be replaced by NULL when it should be.

- Clean up PlaceHolderVars more thoroughly during join removal (Richard Guo, Arne Roland) § §

  This fix corrects various edge cases that could trip assertions or result in incorrect plans.

- Add missed checks for hashability of equality comparisons on container datatypes (arrays, composites, ranges) (Andrei Lepikhov, Tom Lane) §

  The planner must verify hashability of the container's component type(s) before deciding it can use a hash-based plan type. This step was missed in some places, leading to could not identify a hash function failures at execution.

- Avoid pushing `WHERE` clauses down past a grouping step that has a different equivalence rule (Richard Guo) §

  A test on a grouping column that is grouped by a nondeterministic collation is safe to push down only if it is a comparison using that same collation. Otherwise it might filter some rows the grouping would have merged.

- Fix mis-optimization of `COUNT` window functions that have an `EXCLUDE` clause or lack `ORDER BY` (Chengpeng Yan, David Rowley) §

  These window functions were treated as monotonic when they should not be, allowing wrong answers to be computed.

- Avoid cache lookup failed for collation 0 error when planner looks up statistics for a column of type `"char"` (Feng Wu) §

- Fix `ALTER COLUMN ... DROP EXPRESSION` to work when there are multiple levels of partitions (Alberto Piai) §

- Fix attaching partitions of indexes that are exclusion constraints (Japin Li) §

  Notably, this oversight broke dump/restore of partitioned exclusion constraints.

- Prevent setting `NO INHERIT` on partitioned `NOT NULL` constraints via `ALTER CONSTRAINT` (Andreas Karlsson) §

  `NOT NULL` constraints on partitioned tables are supposed to be inherited by all partitions, and therefore must not be marked `NO INHERIT`. This rule was correctly enforced by constraint creation, but not by `ALTER TABLE ... ALTER CONSTRAINT`.

- Disallow renaming a rule to `_RETURN` (Tom Lane) §

  That name is reserved for a view's `ON SELECT` rule, but `ALTER RULE` allowed renaming other rules to `_RETURN`, causing trouble later.

- Fix missing lock release for role membership grants in `DROP OWNED BY` (Jeff Davis) §

  This oversight resulted in a warning message, followed by retaining a lock on the membership grant until the end of the transaction.

- Fix failure of `EXPLAIN` when deparsing `SQL/JSON` aggregates (Richard Guo) §

  Some plan structures resulted in invalid JsonConstructorExpr underlying node type errors.

- Fix use of `REINDEX CONCURRENTLY` with a deferred uniqueness constraint (Nitin Motiani) §

  The transient index copy created during `REINDEX CONCURRENTLY` was incorrectly marked as enforcing immediate uniqueness, causing spurious reports of constraint violation.

- Fix `LIKE` matching with nondeterministic collations and backslashes (Nitin Motiani, Tom Lane) § §

  When using a nondeterministic collation, `LIKE` mishandled an escaped backslash (`\\`), treating it as effectively not there. It also did the wrong thing with a leading backslash preceding an ordinary character; in that case the backslash should be effectively ignored, but it caused the ordinary character to be matched exactly rather than allowing the nondeterministic collation to decide if there's a match.

- Fix `LIKE`/regex optimization for indexscan with exact-match pattern (Jelte Fennema-Nio) §

  Refactoring for `LIKE` with non-deterministic collations accidentally broke the optimization for converting a `LIKE` or regex exact-match pattern to an equality index condition when the index collation doesn't match the expression collation. Among other things, that made psql's `\d `tablename`` command much slower.

- Fix matching of localized month/day names in `to_date()` (Heikki Linnakangas) § §

  The matching logic misbehaved in cases where case-folding changes the byte length of the string.

- Correct case-folding rules for Greek final sigma (Jeff Davis) §

  If the string is preceded only by Case Ignorable characters, don't consider it to be a final sigma. This only affects the built-in `pg_unicode_fast` locale.

- Fix incorrect NFC recomposition for Hangul U+11A7 (TBASE) (Diego Frias, Michael Paquier) §

  This character was treated as a valid T syllable, which it is not, and hence silently swallowed during normalization.

- Avoid possible truncation of output lexemes in case-insensitive `synonym` dictionaries (Jeff Davis) §

  If folding to lower case increased the byte length of a lexeme, it was incorrectly truncated to its original byte length when emitted.

- Defend against truncated UTF-8 characters in case-conversion logic (Jeff Davis) §

- Fix typo in `hash_record_extended()` (Man Zeng) §

  The code failed to initialize the second isnull argument passed to FunctionCallInvoke(). This is harmless for existing in-core extended hash support functions, which will not examine that value. However, extension-provided hash functions could be affected if they inspect `PG_ARGISNULL(1)`.

- Fix `pg_get_publication_tables()` to not fail if a publishable table is dropped concurrently (Bharath Rupireddy) §

- Prevent `satisfies_hash_partition()` from crashing with `VARIADIC NULL` (Robert Haas) §

- Report invalid-weight errors more cleanly and consistently in `tsvector_filter()` and allied functions (Ewan Young) §

  In particular, report weight characters that are not printable ASCII in octal form (`\`nnn``), as `charout()` would render them. This avoids possibly producing an invalidly-encoded error message.

- Reject out-of-range timestamp shift values in `uuidv7()` (Baji Shaik) §

  The shift value must not be so large as to produce a timestamp out of the range that a v7 UUID can represent. Previously, a garbage UUID value was produced.

- Fix mishandling of namespace nodes in `xpath()` (Michael Paquier) § §

  This fix avoids an unexpected could not copy node error.

- Fix `jsonpath`'s `.decimal` method to not throw a hard error for incorrect precision or scale (Ewan Young) § §

  Silent mode should suppress these errors, but failed to.

- Fix NULL-pointer crash when `IS JSON` or similar constructs have an argument that is of string category but lacks a cast to type `text` (Ayush Tiwari) §

  There are no such data types in core PostgreSQL, but the problem is reachable with some extension types.

- Ensure that `SQL/JSON` `ON EMPTY / ON ERROR DEFAULT` values are coerced to the correct typmod (Ewan Young) §

  For example, the declared precision and scale of a `numeric` target column were not applied to the default value.

- Avoid machine-dependent behavior when dividing the smallest possible `money` value by -1 (Andrey Rachitskiy) §

- Fix crash after out-of-memory failure partway through creation of a cache entry for a text search dictionary (Tom Lane) §

- Fix memory-safety bugs in processing of incorrect ispell/hunspell dictionary files (Andrey Rachitskiy) §

- Prevent access to other sessions' temporary tables (Jim Jones, Daniil Davydov, Alexander Korotkov) § §

  Some code paths failed to prevent this, leading to silently wrong (inconsistent) results.

- Prevent no empty local buffer available errors during temporary table access (Melanie Plageman) §

  Limit the number of local buffers that the read streaming mechanism is allowed to use. Previously, a large value of `effective_io_concurrency` could allow a single stream to use all the buffers, resulting in failure.

- Fix the order in which autovacuum processes databases (Rustam Khamidullin) §

  It was unintentionally processing databases from lowest to highest score, when it should be doing the reverse.

- Restore full use of shared buffer pool in `VACUUM`'s wraparound failsafe mode (Melanie Plageman) § §

  An ordinary `VACUUM` is limited to use just a few shared buffers, so as not to impinge too much on other processing. However, in failsafe mode we want to reclaim transaction IDs as quickly as possible, so that limit is supposed to be abandoned to allow vacuuming to proceed as fast as possible. This behavior was accidentally broken during refactoring in v18; restore it.

- Fix memory leak in parallel vacuum worker processes (Baji Shaik) §

  Progress reports from a parallel worker leaked about 1kB per report, with the waste accumulating for the life of the worker process.

- Honor query cancel and vacuum delay during GIN index posting-tree cleanup (Paul Kim, Alexander Korotkov) §

  The posting tree for a common value can be large, so that this missed check could allow vacuum to run for a long time before noticing an interrupt.

- Fix possible mis-decoding of index tuples during GiST and SP-GiST index-only scans (Peter Geoghegan) §

  This error could lead to emitting corrupted data from an index-only scan plan. The only affected core opclass is GiST's range_ops, and it could only fail if the range column were not the first index column.

- Ensure that the new last block of a bulk-extended table is added to its free space map promptly (Jingtang Zhang) §

  An off-by-one error caused the last block of a multi-block table extension to not be marked as free in the map. This would eventually get corrected by vacuum, but meanwhile the space wouldn't be used.

- Avoid possible double-free or infinite error recovery loop in resource cleanup during transaction abort (Tom Lane) §

- When creating directories, tolerate concurrent creation of the same directory (Andrew Dunstan, Tom Lane) §

- Fix JIT-compiled tuple deconstruction code to account correctly for virtual generated columns (David Rowley) §

- Prevent creation of dangling object dependencies by acquiring a shared lock on any object being depended on (Bertrand Drouvot) § §

  The shared lock will conflict with any attempt to drop the depended-on object, eliminating the race condition that formerly existed. For example, if one session drops a schema (that appears empty to it) concurrently with some other session creating a function in that schema, previously both transactions could commit, leaving an invalid function definition behind. Now, one transaction or the other will fail.

- Fix race condition in conflict detection for `SERIALIZABLE` isolation mode (Peter Geoghegan) §

  A conflict could be missed when examining an initially-empty btree index, allowing failure of serializability due to improperly allowing conflicting transactions to commit.

- Fix race condition in ProcSignalBarrier code (Masahiko Sawada) §

  This error could result in processes getting stuck, typically after reporting still waiting for backend with PID `nnnn` to accept ProcSignalBarrier.

- Fix race conditions when a set of processes that belong to the same lock group exit at the same time (Vlad Lesin) § §

  These errors could lead to PANIC aborts, with messages such as latch already owned. The issue does not normally arise in regular parallel query, since the leader won't exit before seeing its workers finish; but some extensions reach the problem.

- Fix WAL logging of operations that clear bits in tables' visibility maps (Melanie Plageman, Andres Freund) § § §

  Such VM changes were missed by the WAL summarizer, potentially leading to incorrect incremental backups. We also failed to log full-page images of such VM pages when needed, potentially allowing torn page writes to go uncorrected. This could lead to misbehavior later, such as wrong results from index-only scans.

- Prevent WAL summarizer process from getting stuck at a timeline switch (Robert Haas) § §

- Fix race with timeline selection in logical decoding during standby promotion (Bertrand Drouvot) § §

  Logical decoding being performed on the standby could fail with a requested WAL segment has already been removed error. A repeat attempt would succeed, so there was no permanent problem but there was an availability hazard.

- Avoid exposing a WAL receiver's full connection string during timeline jumps (Chao Li) §

  The pg_stat_wal_receiver view should show a sanitized version of the connection string, without sensitive data. But it transiently showed the full string when we re-use an existing WAL receiver.

- Use run-time checks, not just Asserts, to verify the correct number of columns in tuples received during logical replication (Varik Matevosyan) §

  A malicious or buggy publisher could send inconsistent numbers of columns. While we could not find a scenario in which this would have serious ill effects, extra caution seems warranted.

- Clean up quoting of string parameters within constructed replication commands (Tom Lane) §

  Various places that generate replication commands were not being adequately careful about quoting replication slot names and other parameters that need to be inserted into those commands. This could result in unexpected syntax errors in those commands. In principle, a crafted replication slot name could result in SQL injection; but such a scenario seems very unlikely to occur in practice, since replication operations can only be invoked by highly-privileged users and there is no reason for them to use a slot name coming from an untrustworthy source.

- Fix logical decoding of empty prepared transactions (Masahiko Sawada) §

  A prepared transaction that did not cause any decodable updates could result in sending `COMMIT/ROLLBACK PREPARED` to the output plugin with no preceding `PREPARE`. For the built-in subscriber this breaks replication, and other plugins will probably not like it either.

- Fix corruption of unlogged sequences after standby promotion (Fujii Masao) §

  Previously, if an unlogged sequence was created on the primary and replicated to a standby, accessing the sequence after promoting the standby could fail with bad magic number in sequence or related errors.

- Fix cascading standby reconnect failure after archive fallback (Marco Nenciarini) §

  A cascading standby could fail to reconnect to its upstream standby with requested starting point ... is ahead of the WAL flush position after falling back to archive recovery.

- Prevent accepting hot-standby connections before WAL replay has reached a consistent database state (Nikhil Sontakke) §

- Do not try to clear pg_database.dathasloginevt locally on a standby server (Ayush Tiwari) §

  Event trigger cleanup tried to perform that action on standby servers as well as the primary. That can't work on a standby, and there's no need anyway since replay of the primary's database change will soon fix it.

- Avoid race condition while dropping obsolete replication slots (Xuneng Zhou) §

  An incorrect unlock and log message could occur if another session immediately re-used the dropped slot's shared-memory entry.

- Avoid race condition while dropping ephemeral replication slots (Zhijie Hou) §

  The slot-releasing code performed some additional updates to the replication slot's shared-memory entry after releasing the slot. This is unsafe since another session could immediately re-use the dropped slot's shared-memory entry. Skip those updates in the case of an ephemeral slot.

- Fix stale progress reports during logical replication table synchronization (Shinya Kato) §

  Previously, the pg_stat_progress_copy view in the subscriber would continue to show the initial `COPY` operation as active even after the data copy had finished. The stale entry remained visible until synchronization caught up with the publisher.

- Clear base backup progress on backup failure (Chao Li) § §

  Previously the pg_stat_progress_basebackup view would continue to show a stale progress entry after a failure, until the replication client disconnected. pg_basebackup normally disconnects immediately, but other clients might not.

- Fix possible PANIC due to concurrent drop of pgstats entries when `track_functions` is enabled (Sami Imseih, Michael Paquier) § § §

- Clean up broken local pgstats entry after failing to obtain space for the corresponding shared hashtable entry (Niall Newman) §

  Failure to do this led to a null-pointer dereference the next time the local entry was used.

- Avoid recording incorrect I/O operation statistics after a failed read or write (Bertrand Drouvot) §

- In PL/Perl, avoid NULL pointer dereference crash when working with an invalid `PostgreSQL::InServer::ARRAY` object (Xing Guo) §

- In PL/Python, properly check for errors when working with sequence and mapping objects (Richard Guo) §

  Previously, a broken object or an unhandled exception could result in a NULL pointer dereference crash.

- In libpq, always drain all pending bytes from the SSL or GSS decryption buffer during `pqReadData()` (Jacob Champion) § § § §

  This avoids edge cases where libpq or its calling application waits for more data to arrive on the socket, but actually all the data has already arrived.

- Improve libpq's handling of out-of-memory conditions (Anthonin Bonnefoy) §

- Fix libpq's trace facility to print new-style BackendKeyData and CancelRequest messages correctly (Anthonin Bonnefoy) §

- Allow libpq to accept ParameterDescription messages exceeding 30000 bytes (Ning Sun) §

  Previously, this message type was not among those that libpq's validity heuristics believed could be long. The limit resulted in failure for prepared queries having more than 7498 parameters, which is unlikely but supported.

- Fix null-pointer crash in ecpg compiler (Jehan-Guillaume de Rorthais) §

  ecpg failed on a `DECLARE` section containing a union nested inside a struct.

- Reject multiple descriptor header items in ecpg's `GET/SET DESCRIPTOR` statements (Masashi Kamura) §

  Previously the grammar allowed this syntax, but broken C code was generated. Adjust the grammar and the documentation to allow only one header item.

- Fix issues with deferred errors in pipeline mode in psql (Michael Paquier) §

  psql could get stuck or suffer an assertion failure in some scenarios where the server reports an error in response to a Sync message, such as a deferred constraint violation.

- Make line widths match in psql's expanded aligned output format (Pavel Stehule) §

  When the table's data rows are narrower than the record header lines, widen the data rows to match the headers, avoiding unsightly output.

- Enforce the intended upper limit for psql's special variable `WATCH_INTERVAL` (Sven Klemm, Daniel Gustafsson) §

  If a too-large value was given, psql reported an error but applied the setting anyway.

- Fix psql's privilege check for showing database size in `\l+` (Christoph Berg) §

  The underlying server function permits users who have `pg_read_all_stats` privileges to see the sizes of all databases, even if they lack `CONNECT` privilege. But psql was unaware of that provision and would not call the function unless the user has `CONNECT` privilege.

- Fix psql's tab completion for `\df` to consider procedures too (Erik Wienhold) §

- Fix thread-safety bug in pgbench (Fujii Masao) §

  When pgbench runs with multiple threads and the `--verbose-errors` option, different threads could attempt to use the same buffer to construct error messages, leading to corrupted log output.

- In pg_combinebackup, prevent infinite loop if the source file is shorter than expected (Peter Eisentraut) §

- Fix cleanup of publisher-side objects after errors in pg_createsubscriber (Nisha Moond) §

  When pg_createsubscriber fails after creating logical replication objects, it should remove the publication and replication slot that it created on the publisher. Some error cases failed to do so.

- Use the source cluster's group-read file permissions for pg_recvlogical output files (Fujii Masao) §

  pg_recvlogical was documented to behave this way, but it never actually enabled group-read.

- Fix inconsistent behavior of pg_restore with `--statistics` or `--statistics-only` (Chao Li, Michael Paquier) § §

  When combined with other selective-restore options such as `--schema`, these options failed to restore the expected items, unlike pg_dump with similar options.

- Fix `vacuumdb --missing-stats-only` to ignore partitioned expression indexes (Baji Shaik) §

  Previously, vacuumdb would always attempt to `ANALYZE` the partitioned table, accomplishing nothing since statistics are never created for partitioned indexes, only for their leaf indexes.

- In `contrib/amcheck`, fix failure to report corruption of a btree metapage's `allequalimage` flag (Chao Li) §

- In `contrib/amcheck`, fix query-lifespan memory leak while verifying a GIN index (Kirill Reshke) §

- In `contrib/amcheck`, handle short-header varlena datums correctly (Andrey Borodin) §

  This error could result in doing excess work while verifying a btree index, but seems not to have had any worse consequences.

- In `contrib/btree_gist`, fix `NaN` handling in the `float4` and `float8` opclasses (Bill Kim, Tom Lane) §

  Comparisons, as well as the GiST penalty and distance functions, did not account for `NaN` and would give the wrong answer when handed one. It is recommended to reindex `btree_gist` indexes on float columns after installing this update, if there is any possibility that there are `NaN` entries in those columns.

- In `contrib/btree_gist`, fix sorting of `bit`/`varbit` entries during GiST index construction (Tom Lane) §

  Values of bit types were sorted as though they were `bytea`s, which did not cause any obvious failure but would result in an inefficient index, since the types' representations are different. It is recommended to reindex `btree_gist` indexes on bit columns after installing this update.

- In `contrib/btree_gist`, fix searches using a not-equal operator (Ayush Tiwari) §

  For variable-length data types, the code for scanning non-leaf index pages applied the wrong comparison function, leading to wrong results and potentially crashes.

- In `contrib/dblink` and `contrib/postgres_fdw`, ensure that a user-mapping setting for `use_scram_passthrough` overrides one for a foreign server (Matheus Alcantara) § §

  Previously the precedence went the other way, but that is inconsistent with the behavior of other foreign-table options.

- Reject setting `use_scram_passthrough` on `contrib/dblink` foreign-data wrappers (Matheus Alcantara) §

  This option is only meaningful on foreign servers and user mappings, but dblink incorrectly allowed it at the FDW level as well (and then ignored it).

- Fix unguarded recursion and loops in `contrib/hstore_plperl`, `contrib/jsonb_plperl`, and `contrib/jsonb_plpython` (Aleksander Alekseev) § §

  Prevent stack overflow when dealing with deeply nested `jsonb` values, and allow interruption of the infinite loop caused when attempting to dereference circular chains of Perl object references.

- Fix missed release of statistics catcache entry in `contrib/intarray` (Man Zeng) §

  This oversight led to warnings like resource was not closed: cache pg_statistic.

- In `contrib/ltree`, fix integer overflow in comparisons (Ayush Tiwari) §

  `ltree` values containing more than about 14,653 labels resulted in wrong comparison answers due to overflow. If a btree index contains such values, it is probably corrupt and should be reindexed after installing this update.

- In `contrib/pgcrypto`, avoid double-free crash after encountering an error while using an OSSLCipher object (Yuelin Wang) §

- Fix out-of-bounds access in `contrib/pg_prewarm`'s autoprewarm worker (Matheus Alcantara) §

  The code tried to fetch a value from one past the end of an array, risking a segfault.

- Fix array overrun in `contrib/pg_surgery`'s `heap_force_kill` and `heap_force_freeze` functions (Michael Paquier) §

  Attempting to change a TID whose offset number equals MaxHeapTuplesPerPage wrote one byte past the end of the allocated array, potentially crashing the server.

- In `contrib/pg_surgery`, avoid infinite loop with TID arrays having more than 64K elements (Andrey Rachitskiy) §

- Avoid NULL-pointer dereference in `contrib/refint`'s `check_foreign_key()` (Ayush Tiwari) §

  In the on-update-cascade case, a null value of a referenced column led to a crash. This is an oversight in the fix for CVE-2026-6637, but the code that was there before that wasn't really right either.

- Fix `contrib/seg` to print segments with `~` certainty indicators correctly (Ewan Young) §

  Due to a typo, `seg_out()` did not print a `~` certainty indicator attached to a segment's upper boundary. Worse, if the lower boundary had `~` while the upper boundary had no indicator, the upper boundary was not printed at all, incorrectly converting the value into an open interval.

- Fix crash with namespace nodes in `contrib/xml2`'s `xpath_nodeset()` function (Andrey Chernyy, Michael Paquier) §

- Support building PostgreSQL with OpenSSL 4 (Daniel Gustafsson) §

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

  Alberta (America/Edmonton) will be on year-round UTC-06 (effectively, permanent DST) beginning in November 2026. This release assumes that their TZ abbreviation will be `CST` from that time forward. That seems likely to change, but it's unclear what new abbreviation will be used.

  Morocco (Africa/Casablanca) will move to permanent UTC+00, without daylight saving time transitions, on 2026-09-20.

## Release 18.4

## Release date:

2026-05-14

This release contains a variety of fixes from 18.3. For information about new features in major release 18, see release-18.

## Migration to Version 18.4

A dump/restore is not required for those running 18.X.

However, if you are upgrading from a version earlier than 18.2, see release-18-2.

## 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)

- Properly quote subscription names in pg_createsubscriber (Nathan Bossart) §

  The given subscription name was inserted into SQL commands without quoting, so that SQL injection could be achieved in the (perhaps unlikely) case that the subscription name comes from an untrusted source.

  The PostgreSQL Project thanks Yu Kunpeng for reporting this problem. (CVE-2026-6476)

- Properly quote object names in logical replication origin checks (Pavel Kohout) §

  `ALTER SUBSCRIPTION ... REFRESH PUBLICATION` interpolated schema and relation names into SQL commands without quoting them, allowing execution of arbitrary SQL on the publisher.

  The PostgreSQL Project thanks Pavel Kohout for reporting this problem. (CVE-2026-6638)

- 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)

- Detect faulty input when restoring attribute MCV statistics (Michael Paquier) §

  The statistics restore functions were insufficiently careful about validating most-common-value statistics, and would accept values that could crash the planner later on.

  The PostgreSQL Project thanks Jeroen Gui for reporting this problem. (CVE-2026-6575)

- 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 `memcmp()` 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 incomplete removal of relation references in `RestrictInfo` structs during join removal (Tom Lane) §

  This oversight has been shown to result in planner failures such as unexpected FULL JOIN is only supported with merge-joinable or hash-joinable join conditions errors. It may also have caused failure to consider valid plans in other cases.

- Improve planner's matching of partition key columns to sub-query outputs (Richard Guo) §

  Strip no-op PlaceHolderVars from operands before comparing them to partition keys. This change enables partition pruning to succeed in some cases where it previously failed to recognize that a partition need not be scanned.

- Fix self-join removal to handle join clauses that are bare boolean columns, e.g. `ON t1.boolcol` (Andrei Lepikhov, Tender Wang, Alexander Korotkov) §

  Previously such a case led to a no relation entry for relid `N` error.

- Fix `UPDATE/DELETE ... WHERE CURRENT OF` to work on tables with virtual generated columns (Satyanarayana Narlapuram, Dean Rasheed) §

- Fix expansion of virtual generated columns in `EXCLUDED` column references in `INSERT ... ON CONFLICT` (Satyanarayana Narlapuram, Dean Rasheed) §

- 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 indexes on virtual generated columns are not supported errors (Robert Haas) §

  Creation of an expression index could sometimes incorrectly report this error.

- 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 TABLE ... SET NOT NULL` to invoke object-access hook functions only after completing the catalog change (Artur Zakirov) §

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

- Fix loss of deferrability of foreign-key triggers (Yasuo Honda) §

  Previously, a foreign key defined as `DEFERRABLE INITIALLY DEFERRED` would behave as `NOT DEFERRABLE` after being set to `NOT ENFORCED` status and then back to `ENFORCED`.

  If you have a foreign key with this problem, it can be repaired (after installing this update) by again setting it to `NOT ENFORCED` and then back to `ENFORCED`.

- Fix `WITHOUT OVERLAPS` to allow domains (Jian He) §

  `UNIQUE/PRIMARY KEY ... WITHOUT OVERLAPS` requires the no-overlap column to be a range or multirange, but it should allow a domain over such a type too.

- 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 `array_agg_array_combine()` to combine the arrays' null bitmaps correctly (Dmytro Astapov) §

  This mistake resulted in sometimes-incorrect output from parallelized `array_agg(anyarray)` calculations.

- Retry `sync_file_range()` if it returns error code `EINTR` (DaeMyung Kang) §

- 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.

- Update activity statistics when a parallel apply worker is idle (Zhijie Hou) §

  Previously, statistics from a recently-completed transaction might go unreported for long intervals, particularly if the workload is light.

- Fix no relation entry for relid 0 failure while estimating array lengths in set operations (Tender Wang) §

- 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.

- Fix incremental JSON parser's handling of numeric tokens that cross input buffer boundaries (Andrew Dunstan) §

  It was possible to accept an incorrectly-formatted number, leading to failures later.

- Prevent bloating relation visibility maps during restore of an incremental backup (Robert Haas) §

  Restore could append many blocks of zeroes to a visibility map, due to incorrect computation of the expected file length. This does not result in data corruption, but it could waste a substantial amount of disk space.

- Use C collation, not the database's default collation, in catalog cache lookups on text columns (Jeff Davis) §

  This avoids failures in edge cases such as physical replication startup, where there is no identified database so that a default collation cannot be determined.

- Prevent stuck slotsync worker processes from blocking promotion of a standby server (Nisha Moond, Ajin Cherian) § § §

  A worker process that was vainly waiting for a response from the primary would delay promotion for an unreasonable amount of time.

- Fix excessive log output from idle slotsync worker processes (Zhijie Hou) §

- 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.

- Make the pg_aios system view's pid column show NULL not 0 when an entry has no owning process (ChangAo Chen) §

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

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

- Fix under-allocation of shared memory used for parallel btree index scans (Siddharth Kothari) §

  In edge cases this could result in a server crash.

- 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 indexing of oldest-multixact arrays in shared memory (Yura Sokolov) § §

  This mistake could cause a prepared-but-not-yet-committed transaction's row locks to appear invisible to other sessions, or other visibility issues for the results of such a transaction. With a very small max_connections setting, memory stomps were also possible.

- Fix array overrun when too many `EXPLAIN` extension options are installed (Joel Jacobson) §

- 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.

- Correctly display join alias Vars that are used in `GROUP BY` (Tom Lane) §

  In views containing queries like `SELECT ... t1 LEFT JOIN t2 USING (x) GROUP BY x`, the `GROUP BY` clause could be displayed incorrectly by deparsing, leading to dump/restore failures. Failures occurred only if `t1.x` and `t2.x` were not of identical data types and `t1.x` was the side that required an implicit coercion.

- Fix minor memory leaks in ICU-based string processing (Jeff Davis) §

- 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) §

- Harden tar-file parsing logic against archives it can't handle (Tom Lane) §

  The tar-file reading code used in pg_basebackup and pg_verifybackup failed to verify that the input is a tar file at all, let alone that it fits into the subset of valid tar files that we can handle. This isn't a problem for the normal scenario where the input file was generated by PostgreSQL code, but it can be an issue if the input has been generated by some other tar program.

- 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_dump, preserve `NO INHERIT` property of `NOT NULL` constraints (Jian He) §

  Some cases missed printing the `NO INHERIT` clause.

- In pg_dumpall, don't skip role `GRANT`s with dangling grantor OIDs (Tom Lane) §

  Instead, handle such cases by emitting `GRANT` without any `GRANTED BY` clause, as we did before v16. This avoids losing the grant in foreseeable cases, since pre-v16 servers didn't prevent dropping the grantor role. Continue to emit a warning about the missing grantor, but only if the source server is v16 or later.

- 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.

- Fix mis-structured output from `contrib/pg_overexplain`'s `RANGE_TABLE` option (Satyanarayana Narlapuram) §

  Some fields were misplaced in JSON, YAML, and XML formats, resulting in structurally invalid output.

- 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 18.3

## Release date:

2026-02-26

This release contains a small number of fixes from 18.2. For information about new features in major release 18, see release-18.

## Migration to Version 18.3

A dump/restore is not required for those running 18.X.

However, if you are upgrading from a version earlier than 18.2, see release-18-2.

## 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 oversight in the fix for CVE-2026-2007 (Zsolt Parragi) §

  If the bounds array needed to be expanded, because the input contained more trigrams than the initial guess, `generate_trgm_only` didn't return the modified array pointer to its caller. That would lead to incorrect output from `strict_word_similarity()` and related functions, or in rare cases a crash. The faulty code is reached if the input string becomes longer when it's converted to lower case. The only known instances of that occur when an ICU locale is used with certain single-byte encodings.

- Fix the volatility marking of `json_strip_nulls()` and `jsonb_strip_nulls()` (Andrew Dunstan) §

  These functions have always been considered immutable, but refactoring in version 18 accidentally marked them stable instead. That prevents their use in index expressions and could cause unnecessary repeat evaluations in queries. This fix corrects the marking in newly-initialized database clusters (including clusters that are pg_upgrade'd to 18.3 or later). However it will not help existing clusters made using 18.0 through 18.2.

  If this mistake affects your usage of these functions, the recommended fix for an existing cluster is a manual catalog update. As superuser, perform

      UPDATE pg_catalog.pg_proc SET provolatile = 'i' WHERE oid IN ('3261','3262');

  in each affected database. Update `template0` and `template1` as well, so that databases made in future will have the fix.

- Fix computation of the set of potentially-nulling outer joins for the output of a `LATERAL UNION ALL` subquery (Richard Guo) §

  This error could lead to skipping `NOT NULL` tests in the mistaken belief that they were unnecessary, resulting in wrong query output.

- Avoid name collisions between user-written constraints and automatically-named `NOT NULL` constraints (Laurenz Albe) §

  As of version 18, `NOT NULL` constraints have full-fledged pg_constraint entries, and therefore require names. The logic for choosing a name for an unnamed `NOT NULL` constraint failed to avoid conflicts with user-written constraints elsewhere in the same `CREATE TABLE` statement.

- 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 18.2

## Release date:

2026-02-12

This release contains a variety of fixes from 18.1. For information about new features in major release 18, see release-18.

## Migration to Version 18.2

A dump/restore is not required for those running 18.X.

However, if you have any indexes on `ltree` columns, it may be necessary to reindex them after updating. See the sixth changelog entry below.

## 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)

- Harden `contrib/pg_trgm` against changes in string lowercasing behavior (Heikki Linnakangas) § §

  Fix potential buffer overruns arising from the fact that in some locales lower-casing a string can produce more characters (not bytes) than were in the original. That behavior is new in version 18, and so is the bug.

  The PostgreSQL Project thanks Heikki Linnakangas for reporting this problem. (CVE-2026-2007)

- Fix inconsistent case-insensitive matching in `contrib/ltree` (Jeff Davis) § §

  Index-related routines in `ltree` used a different implementation of case-folding than the primary operators did. Their behavior was equivalent only if the default collation provider was libc and the encoding was single-byte.

  To fix, change the code to use case-folding with the database's default collation. This change will require reindexing indexes on `ltree` columns (regardless of the index access method) unless the database uses libc as collation provider and its encoding is single-byte. Without that, searches of such indexes will fail to locate relevant entries.

- When using `ALTER TABLE ... ADD CONSTRAINT` to add a not-null constraint with an explicit name, if the column is already marked NOT NULL, require that the provided name match the existing constraint name (Álvaro Herrera, Srinath Reddy Sadipiralla) §

- 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 incorrect pruning of rowmarks belonging to non-relation rangetable entries, such as subqueries (Dean Rasheed) §

  This led to incorrect results if a proposed row update needed to be modified by EvalPlanQual rechecking, as could happen if there was a concurrent update to that row.

- 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.

- Fix expression evaluation bug for a sub-select within an array subscript (Andres Freund) §

- Fix text substring search for non-deterministic collations (Laurenz Albe) §

  When using a non-deterministic collation, we failed to detect a match occurring at the very end of the searched string.

- Avoid possible planner failure when a query contains duplicate window function calls (Meng Zhang, David Rowley) §

  Confusion over de-duplication of such calls could result in errors like WindowFunc with winref 2 assigned to WindowAgg with winref 1.

- Fix planner error with set-returning functions and grouping sets (Richard Guo) §

  When constructing a ProjectSet plan node, the planner failed to detect that subexpressions involving grouping expressions were already computed by the input plan. This led to inefficient plans or errors such as variable not found in subplan target list.

- Avoid incorrect optimization when a subquery's grouping clause contains a volatile or set-returning function (Richard Guo) §

  The planner was willing to push down outer-query restrictions referencing such a grouping column, leading to incorrect behavior due to multiple evaluation of a volatile function, or errors caused by introduction of a set-returning function into the subquery's `WHERE`/`HAVING` clauses.

- Look through PlaceHolderVar nodes when searching for statistics about an expression (Richard Guo) §

  This change allows the planner to find relevant statistics about expressions pulled up from subqueries or used in `GROUP BY`, avoiding falling back to a default estimate. (Arguably we should adjust any found statistics to account for an increased probability of the value being NULL, but we've never done the equivalent thing for plain Vars either.) While this restriction is old, changes in PostgreSQL version 18 made PlaceHolderVars more common than before, so make the change to avoid plan regressions in affected cases.

- Look through no-op PlaceHolderVar nodes when matching expressions to indexes (Richard Guo) §

  Because PostgreSQL version 18 uses PlaceHolderVars in more cases than before, some queries that formerly could use an index failed to do so. Add logic to prevent that regression.

- Fix planner's conversion of `OR` clauses to ScalarArrayOp index conditions (Tender Wang, Tom Lane) §

  The code did not handle RelabelType nodes correctly, and could generate invalid expressions or fail to perform a valid conversion.

- 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.

- Use the correct ordering function in parallel GIN index builds (Tomas Vondra) §

  The parallel code used the default ordering operator (which is determined by the column data type's btree opclass), whereas it should use the ordering function specified by the GIN opclass, if any. This led to a failure if the data type has no btree opclass, or to an invalid index if the opclass specifies an ordering function that doesn't agree with the btree opclass.

- 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.

- Consider grouping expressions when computing a query ID hash (Jian He) §

  Previously, two queries that were the same except in `GROUP BY` expressions would be merged by `contrib/pg_stat_statements` and other users of query IDs.

- Fix erroneous counting of updates in `EXPLAIN ANALYZE MERGE` with a concurrent update (Dean Rasheed) §

  This situation led to an incorrect count of skipped tuples in `EXPLAIN`'s output, or to an assertion failure in an assert-enabled build.

- 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 incorrect handling of incremental backups of large tables (Robert Haas, Oleg Tkachenko) §

  If a table exceeding 1GB (or in general, the installation's segment size) is truncated by `VACUUM` between the base backup and the incremental backup, pg_combinebackup could fail with an error about truncation block length in excess of segment size. This prevented restoring the incremental backup.

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

- Fix race condition in async I/O code (Andres Freund) §

  It was possible for the result code of an asynchronous I/O operation to be overwritten before it was fetched.

- 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.

- Allow retrying initialization of a DSM registry entry (Nathan Bossart) §

  If we fail partway through initialization of a dynamic shared memory entry, allow the next attempt to use that entry to retry initialization. Previously the entry was left in a permanently-failed state.

- Avoid failure of NUMA status views when a page has been swapped out (Tomas Vondra) §

- Avoid operation not permitted errors when querying NUMA page status with older libnuma versions (Tomas Vondra) §

- 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.

- Don't advance logical replication progress after a parallel worker apply failure (Zhijie Hou) §

  The previous behavior allowed transactions to be lost by a subscriber.

- Fix logical replication slotsync worker processes to handle LOCK_TIMEOUT signals correctly (Zhijie Hou) §

  Previously, timeout signals were effectively ignored.

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

- Fix error reporting for SQL/JSON path type mismatches (Jian He) §

  The code could produce a cache lookup failed for type 0 error instead of the intended complaint about the path expression not being of the right type.

- 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.

- Fix aarch64-specific code to build with old (RHEL7-era) system header files (Tom Lane) § §

- Fix incorrect configure probe for `io_uring_queue_init_mem()` (Masahiko Sawada) §

  This error resulted in failure to optimize async I/O buffer allocations in autotools-based builds, though the code did work when building with meson. The main impact of the omission was slower-than-necessary backend process exits.

- Add new server parameter guc-file-extend-method to control use of `posix_fallocate()` (Thomas Munro) §

  PostgreSQL version 16 and later will use `posix_fallocate()`, if the platform provides it, to extend relation files. However, this has been reported to interact poorly with some file systems: BTRFS compression is disabled by the use of `posix_fallocate()`, and XFS could produce spurious `ENOSPC` errors in older Linux kernel versions. To provide a workaround, introduce this new server parameter. Setting `file_extend_method` to `write_zeros` will cause the server to return to the old method of extending files by writing blocks of zeroes.

- Honor `open()`'s `O_CLOEXEC` flag on Windows (Bryan Green, Thomas Munro) § § §

  Make this flag work like it does on POSIX platforms, so that we don't leak file handles into child processes such as `COPY TO/FROM PROGRAM`. While that leakage hasn't caused many problems, it seems undesirable.

- Fix failure to parse long options on the server command line in Solaris executables built with meson (Tom Lane) §

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

- Fix psql's tab completion for `VACUUM` option values (Yugo Nagata) §

- In psql command prompts, do not show a value for `%P` (pipeline status) when there is no server connection (Chao Li) §

  This makes `%P` act like other prompt escape sequences whose values depend on the active connection.

- Fix pg_dump's logic for collecting sequence values (Nathan Bossart) § §

  pg_dump failed if a sequence was dropped concurrently with the dump, even if the sequence was not among the database objects to be dumped. Also, if the calling user lacks privileges to read a sequence's value, pg_dump emitted incorrect values rather than failing as expected.

- Fix potentially-incorrect quoting of `oauth_validator_libraries` values by pg_dump (ChangAo Chen) §

  pg_dump applied the wrong quoting rule if it needed to dump a value of this setting.

- Avoid pg_dump assertion failure in binary-upgrade mode (Vignesh C) §

  Failure to handle subscription-relation objects in the object sorting code triggered an assertion, though there were no serious ill effects in production builds.

- Fix incorrect error handling in pgbench with multiple `\syncpipeline` commands in pipeline mode (Yugo Nagata) §

  If multiple `\syncpipeline` commands are encountered after a query error, pgbench would report failed to exit pipeline mode, or get an assertion failure in an assert-enabled build.

- 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 excessive memory allocation in `contrib/pg_buffercache` (David Geier) §

  The code allocated twice as much memory as it needed for NUMA page status.

- 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.

- Avoid crash in `contrib/pg_stat_statements` when an `IN` list contains both constants and non-constant expressions (Sami Imseih) §

- 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 18.1

## Release date:

2025-11-13

This release contains a variety of fixes from 18.0. For information about new features in major release 18, see release-18.

## Migration to Version 18.1

A dump/restore is not required for those running 18.X.

## 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)

- Prevent unrecognized node type errors when a SQL/JSON function such as `JSON_VALUE` has a `DEFAULT` clause containing a `COLLATE` expression (Jian He) § §

- Avoid incorrect optimization of variable-free `HAVING` clauses with grouping sets (Richard Guo) § §

- Do not use parallelism in hash right semi joins (Richard Guo) §

  The case does not work reliably due to a race condition in updating the join's shared hash table.

- Avoid possible division-by-zero when creating ordered-append plans (Richard Guo) §

  This mistake could result in incorrect selection of the cheapest path, or in an assertion failure in debug builds.

- Fix planner failure with index types that can do ordered access but not index-only scans (Maxime Schoemans) §

  This oversight resulted in errors like no data returned for index-only scan. The case does not arise with any in-core index type, but some extensions encountered the problem.

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

- Avoid possible out-of-memory or invalid memory alloc request size failures during parallel GIN index build (Tomas Vondra) §

- 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 rare crash when processing hashed `GROUPING SETS` queries (David Rowley) §

- Repair faulty hash-table-size-choosing logic in hash joins (Tomas Vondra) §

  Hash joins sometimes used more memory than intended, or failed to divide it in an efficient way.

- Improve relation lookup logic in statistics manipulation functions (Nathan Bossart) § §

  Fix `pg_restore_relation_stats()`, `pg_clear_relation_stats()`, `pg_restore_attribute_stats()`, and `pg_clear_attribute_stats()` to check privileges before acquiring lock on the target relation rather than after.

- 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.

- Fix crash during EvalPlanQual rechecks on partitioned tables (David Rowley, Amit Langote) §

- 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.

- Prevent setting a column as identity if it has a not-null constraint but the constraint is marked as invalid (Jian He) §

  Identity columns must be not-null, but the check for that missed this edge case.

- Avoid potential use-after-free in parallel vacuum (Kevin Oommen Anish) §

  This bug seems to have no consequences in standard builds, but it's theoretically a hazard.

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

- 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) §

- Avoid failures when `synchronized_standby_slots` references nonexistent replication slots (Shlok Kyal) §

- 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.

- Fix mishandling of lock timeout signals in parallel apply workers for logical replication (Hayato Kuroda) §

  The same signal number was being used for both worker shutdown and lock timeout, leading to confusion.

- 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.

- 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 unnecessary invalidation of logical replication slots (Bertrand Drouvot) §

- Re-establish special case for `C` collation in locale setup (Jeff Davis) §

  This fixes a regression in access to shared catalogs early in backend startup, before a database has been selected. It is not known to be a problem for any core PostgreSQL code, but some extensions were broken.

- 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 crash when attempting to test PostgreSQL with certain libsanitizer options (Emmanuel Sibi, Jacob Champion) §

- 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 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.

- Fix dumping of non-inherited not-null constraints on inherited table columns (Dilip Kumar) §

  pg_dump failed to preserve such constraints when dumping from a pre-v18 server.

- Fix pg_dump's sorting of foreign key constraints (Álvaro Herrera) §

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

- 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) §

- Fix per-file memory leakage in pg_combinebackup (Tom Lane) §

- 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.

- In `contrib/pg_stat_statements`, avoid crash when two or more constants are marked as having the same location in the SQL statement text (Sami Imseih, Dmitry Dolgov) §

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

## Release 18

## Release date:

2025-09-25

## Overview

PostgreSQL 18 contains many new features and enhancements, including:

- An asynchronous I/O (AIO) subsystem that can improve performance of sequential scans, bitmap heap scans, vacuums, and other operations.

- pg_upgrade now retains optimizer statistics.

- Support for "skip scan" lookups that allow using multicolumn B-tree indexes in more cases.

- `uuidv7()` function for generating timestamp-ordered UUIDs.

- Virtual generated columns that compute their values during read operations. This is now the default for generated columns.

- OAuth authentication support.

- `OLD` and `NEW` support for `RETURNING` clauses in sql-insert, sql-update, sql-delete, and sql-merge commands.

- Temporal constraints, or constraints over ranges, for PRIMARY KEY, UNIQUE, and FOREIGN KEY constraints.

The above items and other new features of PostgreSQL 18 are explained in more detail in the sections below.

## Migration to Version 18

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 18 contains a number of changes that may affect compatibility with previous releases. Observe the following incompatibilities:

- Change app-initdb default to enable data checksums (Greg Sabino Mullane) §

  Checksums can be disabled with the new initdb option `--no-data-checksums`. pgupgrade requires matching cluster checksum settings, so this new option can be useful to upgrade non-checksum old clusters.

- Change time zone abbreviation handling (Tom Lane) §

  The system will now favor the current session's time zone abbreviations before checking the server variable guc-timezone-abbreviations. Previously `timezone_abbreviations` was checked first.

- Deprecate MD5 password authentication (Nathan Bossart) §

  Support for MD5 passwords will be removed in a future major version release. sql-createrole and sql-alterrole now emit deprecation warnings when setting MD5 passwords. These warnings can be disabled by setting the guc-md5-password-warnings parameter to `off`.

- Change sql-vacuum and sql-analyze to process the inheritance children of a parent (Michael Harris) §

  The previous behavior can be performed by using the new `ONLY` option.

- Prevent `COPY FROM` from treating `\.` as an end-of-file marker when reading CSV files (Daniel Vérité, Tom Lane) § §

  app-psql will still treat `\.` as an end-of-file marker when reading CSV files from `STDIN`. Older psql clients connecting to PostgreSQL 18 servers might experience `\copy` problems. This release also enforces that `\.` must appear alone on a line.

- Disallow unlogged partitioned tables (Michael Paquier) §

  Previously `ALTER TABLE SET [UN]LOGGED` did nothing, and the creation of an unlogged partitioned table did not cause its children to be unlogged.

- Execute `AFTER` triggers as the role that was active when trigger events were queued (Laurenz Albe) §

  Previously such triggers were run as the role that was active at trigger execution time (e.g., at sql-commit). This is significant for cases where the role is changed between queue time and transaction commit.

- Remove non-functional support for rule privileges in sql-grant/sql-revoke (Fujii Masao) §

  These have been non-functional since PostgreSQL 8.2.

- Remove column pg_backend_memory_contexts.parent (Melih Mutlu) §

  This is no longer needed since pg_backend_memory_contexts.path was added.

- Change pg_backend_memory_contexts.level and `pg_log_backend_memory_contexts()` to be one-based (Melih Mutlu, Atsushi Torikoshi, David Rowley, Fujii Masao) § § §

  These were previously zero-based.

- Change full text search to use the default collation provider of the cluster to read configuration files and dictionaries, rather than always using libc (Peter Eisentraut) §

  Clusters that default to non-libc collation providers (e.g., ICU, builtin) that behave differently than libc for characters processed by LC_CTYPE could observe changes in behavior of some full-text search functions, as well as the pgtrgm extension. When upgrading such clusters using pgupgrade, it is recommended to reindex all indexes related to full-text search and pg_trgm after the upgrade.

## Changes

Below you will find a detailed account of the changes between PostgreSQL 18 and the previous major release.

### Server

#### Optimizer

- Automatically remove some unnecessary table self-joins (Andrey Lepikhov, Alexander Kuzmenkov, Alexander Korotkov, Alena Rybakina) §

  This optimization can be disabled using server variable guc-enable-self-join-elimination.

- Convert some `IN (VALUES ...)` to `x = ANY ...` for better optimizer statistics (Alena Rybakina, Andrei Lepikhov) §

- Allow transforming `OR`-clauses to arrays for faster index processing (Alexander Korotkov, Andrey Lepikhov) §

- Speed up the processing of `INTERSECT`, `EXCEPT`, window aggregates, and view column aliases (Tom Lane, David Rowley) § § § §

- Allow the keys of `SELECT DISTINCT` to be internally reordered to avoid sorting (Richard Guo) §

  This optimization can be disabled using guc-enable-distinct-reordering.

- Ignore `GROUP BY` columns that are functionally dependent on other columns (Zhang Mingli, Jian He, David Rowley) §

  If a `GROUP BY` clause includes all columns of a unique index, as well as other columns of the same table, those other columns are redundant and can be dropped from the grouping. This was already true for non-deferred primary keys.

- Allow some `HAVING` clauses on `GROUPING SETS` to be pushed to `WHERE` clauses (Richard Guo) § § § §

  This allows earlier row filtering. This release also fixes some `GROUPING SETS` queries that used to return incorrect results.

- Improve row estimates for `generate_series()` using `numeric` and `timestamp` values (David Rowley, Song Jinzhou) § §

- Allow the optimizer to use `Right Semi Join` plans (Richard Guo) §

  Semi-joins are used when needing to find if there is at least one match.

- Allow merge joins to use incremental sorts (Richard Guo) §

- Improve the efficiency of planning queries accessing many partitions (Ashutosh Bapat, Yuya Watari, David Rowley) § §

- Allow partitionwise joins in more cases, and reduce its memory usage (Richard Guo, Tom Lane, Ashutosh Bapat) § §

- Improve cost estimates of partition queries (Nikita Malakhov, Andrei Lepikhov) §

- Improve SQL-language function plan caching (Alexander Pyhalov, Tom Lane) § §

- Improve handling of disabled optimizer features (Robert Haas) §

#### Indexes

- Allow skip scans of btree indexes (Peter Geoghegan) § §

  This allows multi-column btree indexes to be used in more cases such as when there are no restrictions on the first or early indexed columns (or there are non-equality ones), and there are useful restrictions on later indexed columns.

- Allow non-btree unique indexes to be used as partition keys and in materialized views (Mark Dilger) § §

  The index type must still support equality.

- Allow `GIN` indexes to be created in parallel (Tomas Vondra, Matthias van de Meent) §

- Allow values to be sorted to speed range-type GiST and btree index builds (Bernd Helmle) §

#### General Performance

- Add an asynchronous I/O subsystem (Andres Freund, Thomas Munro, Nazir Bilal Yavuz, Melanie Plageman) § § § § § § § § § § §

  This feature allows backends to queue multiple read requests, which allows for more efficient sequential scans, bitmap heap scans, vacuums, etc. This is enabled by server variable guc-io-method, with server variables guc-io-combine-limit and guc-io-max-combine-limit added to control it. This also enables guc-effective-io-concurrency and guc-maintenance-io-concurrency values greater than zero for systems without `fadvise()` support. The new system view pg_aios shows the file handles being used for asynchronous I/O.

- Improve the locking performance of queries that access many relations (Tomas Vondra) §

- Improve the performance and reduce memory usage of hash joins and `GROUP BY` (David Rowley, Jeff Davis) § § § § §

  This also improves hash set operations used by `EXCEPT`, and hash lookups of subplan values.

- Allow normal vacuums to freeze some pages, even though they are all-visible (Melanie Plageman) § §

  This reduces the overhead of later full-relation freezing. The aggressiveness of this can be controlled by server variable and per-table setting guc-vacuum-max-eager-freeze-failure-rate. Previously vacuum never processed all-visible pages until freezing was required.

- Add server variable guc-vacuum-truncate to control file truncation during sql-vacuum (Nathan Bossart, Gurjeet Singh) §

  A storage-level parameter with the same name and behavior already existed.

- Increase server variables guc-effective-io-concurrency's and guc-maintenance-io-concurrency's default values to 16 (Melanie Plageman) § §

  This more accurately reflects modern hardware.

#### Monitoring

- Increase the logging granularity of server variable guc-log-connections (Melanie Plageman) §

  This server variable was previously only boolean, which is still supported.

- Add `log_connections` option to report the duration of connection stages (Melanie Plageman) §

- Add guc-log-line-prefix escape `%L` to output the client IP address (Greg Sabino Mullane) §

- Add server variable guc-log-lock-failures to log lock acquisition failures (Yuki Seino, Fujii Masao) § §

  Specifically it reports `SELECT ... NOWAIT` lock failures.

- Modify pg_stat_all_tables and its variants to report the time spent in sql-vacuum, sql-analyze, and their automatic variants (Sami Imseih) §

  The new columns are total_vacuum_time, total_autovacuum_time, total_analyze_time, and total_autoanalyze_time.

- Add delay time reporting to sql-vacuum and sql-analyze (Bertrand Drouvot, Nathan Bossart) § §

  This information appears in the server log, the system views pg_stat_progress_vacuum and pg_stat_progress_analyze, and the output of sql-vacuum and sql-analyze when in `VERBOSE` mode; tracking must be enabled with the server variable guc-track-cost-delay-timing.

- Add WAL, CPU, and average read statistics output to `ANALYZE VERBOSE` (Anthonin Bonnefoy) § §

- Add full WAL buffer count to `VACUUM`/`ANALYZE (VERBOSE)` and autovacuum log output (Bertrand Drouvot) §

- Add per-backend I/O statistics reporting (Bertrand Drouvot) § §

  The statistics are accessed via `pg_stat_get_backend_io()`. Per-backend I/O statistics can be cleared via `pg_stat_reset_backend_stats()`.

- Add pg_stat_io columns to report I/O activity in bytes (Nazir Bilal Yavuz) §

  The new columns are read_bytes, write_bytes, and extend_bytes. The op_bytes column, which always equaled `BLCKSZ`, has been removed.

- Add WAL I/O activity rows to pg_stat_io (Nazir Bilal Yavuz, Bertrand Drouvot, Michael Paquier) § § §

  This includes WAL receiver activity and a wait event for such writes.

- Change server variable guc-track-wal-io-timing to control tracking WAL timing in pg_stat_io instead of pg_stat_wal (Bertrand Drouvot) §

- Remove read/sync columns from pg_stat_wal (Bertrand Drouvot) § §

  This removes columns wal_write, wal_sync, wal_write_time, and wal_sync_time.

- Add function `pg_stat_get_backend_wal()` to return per-backend WAL statistics (Bertrand Drouvot) §

  Per-backend WAL statistics can be cleared via `pg_stat_reset_backend_stats()`.

- Add function `pg_ls_summariesdir()` to specifically list the contents of `PGDATA`/`pg_wal/summaries` (Yushi Ogiwara) §

- Add column pg_stat_checkpointer.num_done to report the number of completed checkpoints (Anton A. Melnikov) §

  Columns num_timed and num_requested count both completed and skipped checkpoints.

- Add column pg_stat_checkpointer.slru_written to report SLRU buffers written (Nitin Jadhav) §

  Also, modify the checkpoint server log message to report separate shared buffer and SLRU buffer values.

- Add columns to pg_stat_database to report parallel worker activity (Benoit Lobréau) §

  The new columns are parallel_workers_to_launch and parallel_workers_launched.

- Have query id computation of constant lists consider only the first and last constants (Dmitry Dolgov, Sami Imseih) § § §

  Jumbling is used by pgstatstatements.

- Adjust query id computations to group together queries using the same relation name (Michael Paquier, Sami Imseih) §

  This is true even if the tables in different schemas have different column names.

- Add column pg_backend_memory_contexts.type to report the type of memory context (David Rowley) §

- Add column pg_backend_memory_contexts.path to show memory context parents (Melih Mutlu) §

#### Privileges

- Add function `pg_get_acl()` to retrieve database access control details (Joel Jacobson) § §

- Add function `has_largeobject_privilege()` to check large object privileges (Yugo Nagata) §

- Allow sql-alterdefaultprivileges to define large object default privileges (Takatsuka Haruka, Yugo Nagata, Laurenz Albe) §

- Add predefined role `pg_signal_autovacuum_worker` (Kirill Reshke) §

  This allows sending signals to autovacuum workers.

#### Server Configuration

- Add support for the OAuth authentication method (Jacob Champion, Daniel Gustafsson, Thomas Munro) §

  This adds an `oauth` authentication method to `pg_hba.conf`, libpq OAuth options, a server variable guc-oauth-validator-libraries to load token validation libraries, and a configure flag `--with-libcurl` to add the required compile-time libraries.

- Add server variable guc-ssl-tls13-ciphers to allow specification of multiple colon-separated TLSv1.3 cipher suites (Erica Zhang, Daniel Gustafsson) §

- Change server variable guc-ssl-groups's default to include elliptic curve X25519 (Daniel Gustafsson, Jacob Champion) §

- Rename server variable `ssl_ecdh_curve` to guc-ssl-groups and allow multiple colon-separated ECDH curves to be specified (Erica Zhang, Daniel Gustafsson) §

  The previous name still works.

- Make cancel request keys 256 bits (Heikki Linnakangas, Jelte Fennema-Nio) § §

  This is only possible when the server and client support wire protocol version 3.2, introduced in this release.

- Add server variable guc-autovacuum-worker-slots to specify the maximum number of background workers (Nathan Bossart) §

  With this variable set, guc-autovacuum-max-workers can be adjusted at runtime up to this maximum without a server restart.

- Allow specification of the fixed number of dead tuples that will trigger an autovacuum (Nathan Bossart, Frédéric Yhuel) §

  The server variable is guc-autovacuum-vacuum-max-threshold. Percentages are still used for triggering.

- Change server variable guc-max-files-per-process to limit only files opened by a backend (Andres Freund) §

  Previously files opened by the postmaster were also counted toward this limit.

- Add server variable guc-num-os-semaphores to report the required number of semaphores (Nathan Bossart) §

  This is useful for operating system configuration.

- Add server variable guc-extension-control-path to specify the location of extension control files (Peter Eisentraut, Matheus Alcantara) § §

#### Streaming Replication and Recovery

- Allow inactive replication slots to be automatically invalidated using server variable guc-idle-replication-slot-timeout (Nisha Moond, Bharath Rupireddy) §

- Add server variable guc-max-active-replication-origins to control the maximum active replication origins (Euler Taveira) §

  This was previously controlled by guc-max-replication-slots, but this new setting allows a higher origin count in cases where fewer slots are required.

#### Logical Replication

- Allow the values of generated columns to be logically replicated (Shubham Khanna, Vignesh C, Zhijie Hou, Shlok Kyal, Peter Smith) § § § §

  If the publication specifies a column list, all specified columns, generated and non-generated, are published. Without a specified column list, publication option `publish_generated_columns` controls whether generated columns are published. Previously generated columns were not replicated and the subscriber had to compute the values if possible; this is particularly useful for non-PostgreSQL subscribers which lack such a capability.

- Change the default sql-createsubscription streaming option from `off` to `parallel` (Vignesh C) §

- Allow sql-altersubscription to change the replication slot's two-phase commit behavior (Hayato Kuroda, Ajin Cherian, Amit Kapila, Zhijie Hou) § §

- Log conflicts while applying logical replication changes (Zhijie Hou, Nisha Moond) § § § § §

  Also report in new columns of pg_stat_subscription_stats.

### Utility Commands

- Allow generated columns to be virtual, and make them the default (Peter Eisentraut, Jian He, Richard Guo, Dean Rasheed) § § §

  Virtual generated columns generate their values when the columns are read, not written. The write behavior can still be specified via the `STORED` option.

- Add `OLD`/`NEW` support to `RETURNING` in DML queries (Dean Rasheed) §

  Previously `RETURNING` only returned new values for sql-insert and sql-update, and old values for sql-delete; sql-merge would return the appropriate value for the internal query executed. This new syntax allows the `RETURNING` list of `INSERT`/`UPDATE`/`DELETE`/`MERGE` to explicitly return old and new values by using the special aliases `old` and `new`. These aliases can be renamed to avoid identifier conflicts.

- Allow foreign tables to be created like existing local tables (Zhang Mingli) §

  The syntax is `CREATE FOREIGN TABLE ... LIKE`.

- Allow `LIKE` with nondeterministic collations (Peter Eisentraut) §

- Allow text position search functions with nondeterministic collations (Peter Eisentraut) §

  These used to generate an error.

- Add builtin collation provider `PG_UNICODE_FAST` (Jeff Davis) §

  This locale supports case mapping, but sorts in code point order, not natural language order.

- Allow sql-vacuum and sql-analyze to process partitioned tables without processing their children (Michael Harris) §

  This is enabled with the new `ONLY` option. This is useful since autovacuum does not process partitioned tables, just its children.

- Add functions to modify per-relation and per-column optimizer statistics (Corey Huinker) § § §

  The functions are `pg_restore_relation_stats()`, `pg_restore_attribute_stats()`, `pg_clear_relation_stats()`, and `pg_clear_attribute_stats()`.

- Add server variable guc-file-copy-method to control the file copying method (Nazir Bilal Yavuz) §

  This controls whether `CREATE DATABASE ... STRATEGY=FILE_COPY` and `ALTER DATABASE ... SET TABLESPACE` uses file copy or clone.

#### Constraints

- Allow the specification of non-overlapping `PRIMARY KEY`, `UNIQUE`, and foreign key constraints (Paul A. Jungwirth) § §

  This is specified by `WITHOUT OVERLAPS` for `PRIMARY KEY` and `UNIQUE`, and by `PERIOD` for foreign keys, all applied to the last specified column.

- Allow `CHECK` and foreign key constraints to be specified as `NOT ENFORCED` (Amul Sul) § §

  This also adds column pg_constraint.conenforced.

- Require primary/foreign key relationships to use either deterministic collations or the the same nondeterministic collations (Peter Eisentraut) §

  The restore of a app-pgdump, also used by pgupgrade, will fail if these requirements are not met; schema changes must be made for these upgrade methods to succeed.

- Store column `NOT NULL` specifications in pg_constraint (Álvaro Herrera, Bernd Helmle) § §

  This allows names to be specified for `NOT NULL` constraint. This also adds `NOT NULL` constraints to foreign tables and `NOT NULL` inheritance control to local tables.

- Allow sql-altertable to set the `NOT VALID` attribute of `NOT NULL` constraints (Rushabh Lathia, Jian He) §

- Allow modification of the inheritability of `NOT NULL` constraints (Suraj Kharage, Álvaro Herrera) § §

  The syntax is `ALTER TABLE ... ALTER CONSTRAINT ... [NO] INHERIT`.

- Allow `NOT VALID` foreign key constraints on partitioned tables (Amul Sul) §

- Allow dropping of constraints `ONLY` on partitioned tables (Álvaro Herrera) §

  This was previously erroneously prohibited.

#### sql-copy

- Add `REJECT_LIMIT` to control the number of invalid rows `COPY FROM` can ignore (Atsushi Torikoshi) §

  This is available when `ON_ERROR = 'ignore'`.

- Allow `COPY TO` to copy rows from populated materialized views (Jian He) §

- Add `COPY` `LOG_VERBOSITY` level `silent` to suppress log output of ignored rows (Atsushi Torikoshi) §

  This new level suppresses output for discarded input rows when `on_error = 'ignore'`.

- Disallow `COPY FREEZE` on foreign tables (Nathan Bossart) §

  Previously, the `COPY` worked but the `FREEZE` was ignored, so disallow this command.

#### sql-explain

- Automatically include `BUFFERS` output in `EXPLAIN ANALYZE` (Guillaume Lelarge, David Rowley) §

- Add full WAL buffer count to `EXPLAIN (WAL)` output (Bertrand Drouvot) §

- In `EXPLAIN ANALYZE`, report the number of index lookups used per index scan node (Peter Geoghegan) §

- Modify `EXPLAIN` to output fractional row counts (Ibrar Ahmed, Ilia Evdokimov, Robert Haas) § §

- Add memory and disk usage details to `Material`, `Window Aggregate`, and common table expression nodes to `EXPLAIN` output (David Rowley, Tatsuo Ishii) § § § §

- Add details about window function arguments to `EXPLAIN` output (Tom Lane) §

- Add `Parallel Bitmap Heap Scan` worker cache statistics to `EXPLAIN ANALYZE` (David Geier, Heikki Linnakangas, Donghang Lin, Alena Rybakina, David Rowley) §

- Indicate disabled nodes in `EXPLAIN ANALYZE` output (Robert Haas, David Rowley, Laurenz Albe) § § §

### Data Types

- Improve Unicode full case mapping and conversion (Jeff Davis) § §

  This adds the ability to do conditional and title case mapping, and case map single characters to multiple characters.

- Allow `jsonb` `null` values to be cast to scalar types as `NULL` (Tom Lane) §

  Previously such casts generated an error.

- Add optional parameter to `json{b}_strip_nulls` to allow removal of null array elements (Florents Tselai) §

- Add function `array_sort()` which sorts an array's first dimension (Junwang Zhao, Jian He) §

- Add function `array_reverse()` which reverses an array's first dimension (Aleksander Alekseev) §

- Add function `reverse()` to reverse bytea bytes (Aleksander Alekseev) §

- Allow casting between integer types and `bytea` (Aleksander Alekseev) §

  The integer values are stored as `bytea` two's complement values.

- Update Unicode data to Unicode 16.0.0 (Peter Eisentraut) §

- Add full text search stemming for Estonian (Tom Lane) §

- Improve the `XML` error codes to more closely match the SQL standard (Tom Lane) §

  These errors are reported via `SQLSTATE`.

### Functions

- Add function `casefold()` to allow for more sophisticated case-insensitive matching (Jeff Davis) §

  This allows more accurate comparisons, i.e., a character can have multiple upper or lower case equivalents, or upper or lower case conversion changes the number of characters.

- Allow `MIN()`/`MAX()` aggregates on arrays and composite types (Aleksander Alekseev, Marat Buharov) § §

- Add a `WEEK` option to `EXTRACT()` (Tom Lane) §

- Improve the output `EXTRACT(QUARTER ...)` for negative values (Tom Lane) §

- Add roman numeral support to `to_number()` (Hunaid Sohail) §

  This is accessed via the `RN` pattern.

- Add `UUID` version 7 generation function `uuidv7()` (Andrey Borodin) §

  This `UUID` value is temporally sortable. Function alias `uuidv4()` has been added to explicitly generate version 4 UUIDs.

- Add functions `crc32()` and `crc32c()` to compute CRC values (Aleksander Alekseev) §

- Add math functions `gamma()` and `lgamma()` (Dean Rasheed) §

- Allow `=>` syntax for named cursor arguments in PL/pgSQL (Pavel Stehule) §

  We previously only accepted `:=`.

- Allow `regexp_match[es]()`/`regexp_like()`/`regexp_replace()`/`regexp_count()`/`regexp_instr()`/`regexp_substr()`/`regexp_split_to_table()`/`regexp_split_to_array()` to use named arguments (Jian He) §

### Libpq

- Add function `PQfullProtocolVersion()` to report the full, including minor, protocol version number (Jacob Champion, Jelte Fennema-Nio) §

- Add libpq connection parameters and environment variables to specify the minimum and maximum acceptable protocol version for connections (Jelte Fennema-Nio) § §

- Report guc-search-path changes to the client (Alexander Kukushkin, Jelte Fennema-Nio, Tomas Vondra) § §

- Add `PQtrace()` output for all message types, including authentication (Jelte Fennema-Nio) § § § § §

- Add libpq connection parameter `sslkeylogfile` which dumps out SSL key material (Abhishek Chanda, Daniel Gustafsson) §

  This is useful for debugging.

- Modify some libpq function signatures to use `int64_t` (Thomas Munro) §

  These previously used `pg_int64`, which is now deprecated.

### app-psql

- Allow psql to parse, bind, and close named prepared statements (Anthonin Bonnefoy, Michael Paquier) § §

  This is accomplished with new commands `\parse`, `\bind_named`, and `\close_prepared`.

- Add psql backslash commands to allowing issuance of pipeline queries (Anthonin Bonnefoy) § § §

  The new commands are `\startpipeline`, `\syncpipeline`, `\sendpipeline`, `\endpipeline`, `\flushrequest`, `\flush`, and `\getresults`.

- Allow adding pipeline status to the psql prompt and add related state variables (Anthonin Bonnefoy) §

  The new prompt character is `%P` and the new psql variables are `PIPELINE_SYNC_COUNT`, `PIPELINE_COMMAND_COUNT`, and `PIPELINE_RESULT_COUNT`.

- Allow adding the connection service name to the psql prompt or access it via psql variable (Michael Banck) §

- Add psql option to use expanded mode on all list commands (Dean Rasheed) §

  Adding backslash suffix `x` enables this.

- Change psql's app-psql-meta-command-conninfo to use tabular format and include more information (Álvaro Herrera, Maiquel Grassi, Hunaid Sohail) §

- Add function's leakproof indicator to psql's `\df+`, `\do+`, `\dAo+`, and `\dC+` outputs (Yugo Nagata) §

- Add access method details for partitioned relations in `\dP+` (Justin Pryzby) §

- Add `default_version` to the psql `\dx` extension output (Magnus Hagander) §

- Add psql variable app-psql-variables-watch-interval to set the default `\watch` wait time (Daniel Gustafsson) §

### Server Applications

- Change app-initdb to default to enabling checksums (Greg Sabino Mullane) § §

  The new initdb option `--no-data-checksums` disables checksums.

- Add initdb option `--no-sync-data-files` to avoid syncing heap/index files (Nathan Bossart) §

  initdb option `--no-sync` is still available to avoid syncing any files.

- Add app-vacuumdb option `--missing-stats-only` to compute only missing optimizer statistics (Corey Huinker, Nathan Bossart) § §

  This option can only be run by superusers and can only be used with options `--analyze-only` and `--analyze-in-stages`.

- Add app-pgcombinebackup option `-k`/`--link` to enable hard linking (Israel Barth Rubio, Robert Haas) §

  Only some files can be hard linked. This should not be used if the backups will be used independently.

- Allow app-pgverifybackup to verify tar-format backups (Amul Sul) §

- If app-pgrewind's `--source-server` specifies a database name, use it in `--write-recovery-conf` output (Masahiko Sawada) §

- Add app-pgresetwal option `--char-signedness` to change the default `char` signedness (Masahiko Sawada) §

#### pg_dump/pg_dumpall/pg_restore

- Add app-pgdump option `--statistics` (Jeff Davis) § §

- Add pg_dump and app-pg-dumpall option `--sequence-data` to dump sequence data that would normally be excluded (Nathan Bossart) § §

- Add app-pgdump, app-pg-dumpall, and app-pgrestore options `--statistics-only`, `--no-statistics`, `--no-data`, and `--no-schema` (Corey Huinker, Jeff Davis) §

- Add option `--no-policies` to disable row level security policy processing in app-pgdump, app-pg-dumpall, app-pgrestore (Nikolay Samokhvalov) §

  This is useful for migrating to systems with different policies.

#### pgupgrade

- Allow pg_upgrade to preserve optimizer statistics (Corey Huinker, Jeff Davis, Nathan Bossart) § § § §

  Extended statistics are not preserved. Also add pg_upgrade option `--no-statistics` to disable statistics preservation.

- Allow pg_upgrade to process database checks in parallel (Nathan Bossart) § § § § § § § § § § §

  This is controlled by the existing `--jobs` option.

- Add pg_upgrade option `--swap` to swap directories rather than copy, clone, or link files (Nathan Bossart) §

  This mode is potentially the fastest.

- Add pg_upgrade option `--set-char-signedness` to set the default `char` signedness of new cluster (Masahiko Sawada) § §

  This is to handle cases where a pre-PostgreSQL 18 cluster's default CPU signedness does not match the new cluster.

#### Logical Replication Applications

- Add app-pgcreatesubscriber option `--all` to create logical replicas for all databases (Shubham Khanna) §

- Add pg_createsubscriber option `--clean` to remove publications (Shubham Khanna) § §

- Add pg_createsubscriber option `--enable-two-phase` to enable prepared transactions (Shubham Khanna) §

- Add app-pgrecvlogical option `--enable-failover` to specify failover slots (Hayato Kuroda) §

  Also add option `--enable-two-phase` as a synonym for `--two-phase`, and deprecate the latter.

- Allow pg_recvlogical `--drop-slot` to work without `--dbname` (Hayato Kuroda) §

### Source Code

- Separate the loading and running of injection points (Michael Paquier, Heikki Linnakangas) § §

  Injection points can now be created, but not run, via `INJECTION_POINT_LOAD()`, and such injection points can be run via `INJECTION_POINT_CACHED()`.

- Support runtime arguments in injection points (Michael Paquier) §

- Allow inline injection point test code with `IS_INJECTION_POINT_ATTACHED()` (Heikki Linnakangas) §

- Improve the performance of processing long `JSON` strings using SIMD (Single Instruction Multiple Data) (David Rowley) §

- Speed up CRC32C calculations using x86 AVX-512 instructions (Raghuveer Devulapalli, Paul Amonson) §

- Add ARM Neon and SVE CPU intrinsics for popcount (integer bit counting) (Chiranmoy Bhattacharya, Devanga Susmitha, Rama Malladi) § §

- Improve the speed of numeric multiplication and division (Joel Jacobson, Dean Rasheed) § § § §

- Add configure option `--with-libnuma` to enable NUMA awareness (Jakub Wartak, Bertrand Drouvot) § § §

  The function `pg_numa_available()` reports on NUMA awareness, and system views pg_shmem_allocations_numa and pg_buffercache_numa which report on shared memory distribution across NUMA nodes.

- Add TOAST table to pg_index to allow for very large expression indexes (Nathan Bossart) §

- Remove column pg_attribute.attcacheoff (David Rowley) §

- Add column pg_class.relallfrozen (Melanie Plageman) §

- Add amgettreeheight, `amconsistentequality`, and `amconsistentordering` to the index access method API (Mark Dilger) § §

- Add GiST support function `stratnum()` (Paul A. Jungwirth) §

- Record the default CPU signedness of `char` in app-pgcontroldata (Masahiko Sawada) §

- Add support for Python "Limited API" in PL/Python (Peter Eisentraut) § §

  This helps prevent problems caused by Python 3.x version mismatches.

- Change the minimum supported Python version to 3.6.8 (Jacob Champion) §

- Remove support for OpenSSL versions older than 1.1.1 (Daniel Gustafsson) § §

- If LLVM is enabled, require version 14 or later (Thomas Munro) §

- Add macro `PG_MODULE_MAGIC_EXT` to allow extensions to report their name and version (Andrei Lepikhov) §

  This information can be access via the new function `pg_get_loaded_modules()`.

- Document that `SPI_connect()`/`SPI_connect_ext()` always returns success (`SPI_OK_CONNECT`) (Stepan Neretin) §

  Errors are always reported via `ereport()`.

- Add documentation section about API and ABI compatibility (David Wheeler, Peter Eisentraut) §

- Remove the experimental designation of Meson builds on `Windows` (Aleksander Alekseev) §

- Remove configure options `--disable-spinlocks` and `--disable-atomics` (Thomas Munro) § §

  Thirty-two-bit atomic operations are now required.

- Remove support for the HPPA/PA-RISC architecture (Tom Lane) §

### Additional Modules

- Add extension pglogicalinspect to inspect logical snapshots (Bertrand Drouvot) §

- Add extension pgoverexplain which adds debug details to `EXPLAIN` output (Robert Haas) §

- Add output columns to `postgres_fdw_get_connections()` (Hayato Kuroda, Sagar Dilip Shedge) § § § §

  New output column used_in_xact indicates if the foreign data wrapper is being used by a current transaction, closed indicates if it is closed, user_name indicates the user name, and remote_backend_pid indicates the remote backend process identifier.

- Allow SCRAM authentication from the client to be passed to postgres-fdw servers (Matheus Alcantara, Peter Eisentraut) §

  This avoids storing postgres_fdw authentication information in the database, and is enabled with the postgres_fdw `use_scram_passthrough` connection option. libpq uses new connection parameters libpq-connect-scram-client-key and libpq-connect-scram-server-key.

- Allow SCRAM authentication from the client to be passed to dblink servers (Matheus Alcantara) §

- Add `on_error` and `log_verbosity` options to file-fdw (Atsushi Torikoshi) §

  These control how file_fdw handles and reports invalid file rows.

- Add `reject_limit` to control the number of invalid rows file_fdw can ignore (Atsushi Torikoshi) §

  This is active when `ON_ERROR = 'ignore'`.

- Add configurable variable `min_password_length` to passwordcheck (Emanuele Musella, Maurizio Boriani) §

  This controls the minimum password length.

- Have pgbench report the number of failed, retried, or skipped transactions in per-script reports (Yugo Nagata) §

- Add isn server variable `weak` to control invalid check digit acceptance (Viktor Holmberg) §

  This was previously only controlled by function `isn_weak()`.

- Allow values to be sorted to speed btree-gist index builds (Bernd Helmle, Andrey Borodin) §

- Add amcheck check function `gin_index_check()` to verify `GIN` indexes (Grigory Kryachko, Heikki Linnakangas, Andrey Borodin) §

- Add functions `pg_buffercache_evict_relation()` and `pg_buffercache_evict_all()` to evict unpinned shared buffers (Nazir Bilal Yavuz) §

  The existing function `pg_buffercache_evict()` now returns the buffer flush status.

- Allow extensions to install custom sql-explain options (Robert Haas, Sami Imseih) § § §

- Allow extensions to use the server's cumulative statistics API (Michael Paquier) § §

#### pgstatstatements

- Allow the queries of sql-createtableas and sql-declare to be tracked by pg_stat_statements (Anthonin Bonnefoy) §

  They are also now assigned query ids.

- Allow the parameterization of sql-set values in pg_stat_statements (Greg Sabino Mullane, Michael Paquier) §

  This reduces the bloat caused by `SET` statements with differing constants.

- Add pg_stat_statements columns to report parallel activity (Guillaume Lelarge) §

  The new columns are parallel_workers_to_launch and parallel_workers_launched.

- Add pg_stat_statements.wal_buffers_full to report full WAL buffers (Bertrand Drouvot) §

#### pgcrypto

- Add pgcrypto algorithms `sha256crypt` and `sha512crypt` (Bernd Helmle) §

- Add CFB mode to pgcrypto encryption and decryption (Umar Hayat) §

- Add function `fips_mode()` to report the server's FIPS mode (Daniel Gustafsson) §

- Add pgcrypto server variable `builtin_crypto_enabled` to allow disabling builtin non-FIPS mode cryptographic functions (Daniel Gustafsson, Joe Conway) §

  This is useful for guaranteeing FIPS mode behavior.

## Acknowledgments

The following individuals (in alphabetical order) have contributed to this release as patch authors, committers, reviewers, testers, or reporters of issues.

- Abhishek Chanda
- Adam Guo
- Adam Rauch
- Aidar Imamov
- Ajin Cherian
- Alastair Turner
- Alec Cozens
- Aleksander Alekseev
- Alena Rybakina
- Alex Friedman
- Alex Richman
- Alexander Alehin
- Alexander Borisov
- Alexander Korotkov
- Alexander Kozhemyakin
- Alexander Kukushkin
- Alexander Kuzmenkov
- Alexander Kuznetsov
- Alexander Lakhin
- Alexander Pyhalov
- Alexandra Wang
- Alexey Dvoichenkov
- Alexey Makhmutov
- Alexey Shishkin
- Ali Akbar
- Álvaro Herrera
- Álvaro Mongil
- Amit Kapila
- Amit Langote
- Amul Sul
- Andreas Karlsson
- Andreas Scherbaum
- Andreas Ulbrich
- Andrei Lepikhov
- Andres Freund
- Andrew
- Andrew Bille
- Andrew Dunstan
- Andrew Jackson
- Andrew Kane
- Andrew Watkins
- Andrey Borodin
- Andrey Chudnovsky
- Andrey Rachitskiy
- Andrey Rudometov
- Andy Alsup
- Andy Fan
- Anthonin Bonnefoy
- Anthony Hsu
- Anthony Leung
- Anton Melnikov
- Anton Voloshin
- Antonin Houska
- Antti Lampinen
- Arseniy Mukhin
- Artur Zakirov
- Arun Thirupathi
- Ashutosh Bapat
- Asphator
- Atsushi Torikoshi
- Avi Weinberg
- Aya Iwata
- Ayush Tiwari
- Ayush Vatsa
- Bastien Roucariès
- Ben Peachey Higdon
- Benoit Lobréau
- Bernd Helmle
- Bernd Reiß
- Bernhard Wiedemann
- Bertrand Drouvot
- Bertrand Mamasam
- Bharath Rupireddy
- Bogdan Grigorenko
- Boyu Yang
- Braulio Fdo Gonzalez
- Bruce Momjian
- Bykov Ivan
- Cameron Vogt
- Cary Huang
- Cédric Villemain
- Cees van Zeeland
- ChangAo Chen
- Chao Li
- Chapman Flack
- Charles Samborski
- Chengwen Wu
- Chengxi Sun
- Chiranmoy Bhattacharya
- Chris Gooch
- Christian Charukiewicz
- Christoph Berg
- Christophe Courtois
- Christopher Inokuchi
- Clemens Ruck
- Corey Huinker
- Craig Milhiser
- Crisp Lee
- Dagfinn Ilmari Mannsåker
- Daniel Elishakov
- Daniel Gustafsson
- Daniel Vérité
- Daniel Westermann
- Daniele Varrazzo
- Daniil Davydov
- Daria Shanina
- Dave Cramer
- Dave Page
- David Benjamin
- David Christensen
- David Fiedler
- David G. Johnston
- David Geier
- David Rowley
- David Steele
- David Wheeler
- David Zhang
- Davinder Singh
- Dean Rasheed
- Devanga Susmitha
- Devrim Gündüz
- Dian Fay
- Dilip Kumar
- Dimitrios Apostolou
- Dipesh Dhameliya
- Dmitrii Bondar
- Dmitry Dolgov
- Dmitry Koval
- Dmitry Kovalenko
- Dmitry Yurichev
- Dominique Devienne
- Donghang Lin
- Dorjpalam Batbaatar
- Drew Callahan
- Duncan Sands
- Dwayne Towell
- Dzmitry Jachnik
- Egor Chindyaskin
- Egor Rogov
- Emanuel Ionescu
- Emanuele Musella
- Emre Hasegeli
- Eric Cyr
- Erica Zhang
- Erik Nordström
- Erik Rijkers
- Erik Wienhold
- Erki Eessaar
- Ethan Mertz
- Etienne LAFARGE
- Etsuro Fujita
- Euler Taveira
- Evan Si
- Evgeniy Gorbanev
- Fabio R. Sluzala
- Fabrízio de Royes Mello
- Feike Steenbergen
- Feliphe Pozzer
- Felix
- Fire Emerald
- Florents Tselai
- Francesco Degrassi
- Frank Streitzig
- Frédéric Yhuel
- Fredrik Widlert
- Gabriele Bartolini
- Gavin Panella
- Geoff Winkless
- George MacKerron
- Gilles Darold
- Grant Gryczan
- Greg Burd
- Greg Sabino Mullane
- Greg Stark
- Grigory Kryachko
- Guillaume Lelarge
- Gunnar Morling
- Gunnar Wagner
- Gurjeet Singh
- Haifang Wang
- Hajime Matsunaga
- Hamid Akhtar
- Hannu Krosing
- Hari Krishna Sunder
- Haruka Takatsuka
- Hayato Kuroda
- Heikki Linnakangas
- Hironobu Suzuki
- Holger Jakobs
- Hubert Lubaczewski
- Hugo Dubois
- Hugo Zhang
- Hunaid Sohail
- Hywel Carver
- Ian Barwick
- Ibrar Ahmed
- Igor Gnatyuk
- Igor Korot
- Ilia Evdokimov
- Ilya Gladyshev
- Ilyasov Ian
- Imran Zaheer
- Isaac Morland
- Israel Barth Rubio
- Ivan Kush
- Jacob Brazeal
- Jacob Champion
- Jaime Casanova
- Jakob Egger
- Jakub Wartak
- James Coleman
- James Hunter
- Jan Behrens
- Japin Li
- Jason Smith
- Jayesh Dehankar
- Jeevan Chalke
- Jeff Davis
- Jehan-Guillaume de Rorthais
- Jelte Fennema-Nio
- Jian He
- Jianghua Yang
- Jiao Shuntian
- Jim Jones
- Jim Nasby
- Jingtang Zhang
- Jingzhou Fu
- Joe Conway
- Joel Jacobson
- John Hutchins
- John Naylor
- Jonathan Katz
- Jorge Solórzano
- José Villanova
- Josef Šimánek
- Joseph Koshakow
- Julien Rouhaud
- Junwang Zhao
- Justin Pryzby
- Kaido Vaikla
- Kaimeh
- Karina Litskevich
- Karthik S
- Kartyshov Ivan
- Kashif Zeeshan
- Keisuke Kuroda
- Kevin Hale Boyes
- Kevin K Biju
- Kirill Reshke
- Kirill Zdornyy
- Koen De Groote
- Koichi Suzuki
- Koki Nakamura
- Konstantin Knizhnik
- Kouhei Sutou
- Kuntal Ghosh
- Kyotaro Horiguchi
- Lakshmi Narayana Velayudam
- Lars Kanis
- Laurence Parry
- Laurenz Albe
- Lele Gaifax
- Li Yong
- Lilian Ontowhee
- Lingbin Meng
- Luboslav Špilák
- Luca Vallisa
- Lukas Fittl
- Maciek Sakrejda
- Magnus Hagander
- Mahendra Singh Thalor
- Mahendrakar Srinivasarao
- Maiquel Grassi
- Maksim Korotkov
- Maksim Melnikov
- Man Zeng
- Marat Buharov
- Marc Balmer
- Marco Nenciarini
- Marcos Pegoraro
- Marina Polyakova
- Mark Callaghan
- Mark Dilger
- Marlene Brandstaetter
- Marlene Reiterer
- Martin Rakhmanov
- Masahiko Sawada
- Masahiro Ikeda
- Masao Fujii
- Mason Mackaman
- Mat Arye
- Matheus Alcantara
- Mats Kindahl
- Matthew Gabeler-Lee
- Matthew Kim
- Matthew Sterrett
- Matthew Woodcraft
- Matthias van de Meent
- Matthieu Denais
- Maurizio Boriani
- Max Johnson
- Max Madden
- Maxim Boguk
- Maxim Orlov
- Maximilian Chrzan
- Melanie Plageman
- Melih Mutlu
- Mert Alev
- Michael Banck
- Michael Bondarenko
- Michael Christofides
- Michael Guissine
- Michael Harris
- Michaël Paquier
- Michail Nikolaev
- Michal Kleczek
- Michel Pelletier
- Mikaël Gourlaouen
- Mikhail Gribkov
- Mikhail Kot
- Milosz Chmura
- Muralikrishna Bandaru
- Murat Efendioglu
- Mutaamba Maasha
- Naeem Akhter
- Nat Makarevitch
- Nathan Bossart
- Navneet Kumar
- Nazir Bilal Yavuz
- Neil Conway
- Niccolò Fei
- Nick Davies
- Nicolas Maus
- Niek Brasa
- Nikhil Raj
- Nikita
- Nikita Kalinin
- Nikita Malakhov
- Nikolay Samokhvalov
- Nikolay Shaplov
- Nisha Moond
- Nitin Jadhav
- Nitin Motiani
- Noah Misch
- Noboru Saito
- Noriyoshi Shinoda
- Ole Peder Brandtzæg
- Oleg Sibiryakov
- Oleg Tselebrovskiy
- Olleg Samoylov
- Onder Kalaci
- Ondrej Navratil
- Patrick Stählin
- Paul Amonson
- Paul Jungwirth
- Paul Ramsey
- Pavel Borisov
- Pavel Luzanov
- Pavel Nekrasov
- Pavel Stehule
- Peter Eisentraut
- Peter Geoghegan
- Peter Mittere
- Peter Smith
- Phil Eaton
- Philipp Salvisberg
- Philippe Beaudoin
- Pierre Giraud
- Pixian Shi
- Polina Bungina
- Przemyslaw Sztoch
- Quynh Tran
- Rafia Sabih
- Raghuveer Devulapalli
- Rahila Syed
- Rama Malladi
- Ran Benita
- Ranier Vilela
- Renan Alves Fonseca
- Richard Guo
- Richard Neill
- Rintaro Ikeda
- Robert Haas
- Robert Treat
- Robins Tharakan
- Roman Zharkov
- Ronald Cruz
- Ronan Dunklau
- Rui Zhao
- Rushabh Lathia
- Rustam Allakov
- Ryo Kanbayashi
- Ryohei Takahashi
- RyotaK
- Sagar Dilip Shedge
- Salvatore Dipietro
- Sam Gabrielsson
- Sam James
- Sameer Kumar
- Sami Imseih
- Samuel Thibault
- Satyanarayana Narlapuram
- Sebastian Skalacki
- Senglee Choi
- Sergei Kornilov
- Sergey Belyashov
- Sergey Dudoladov
- Sergey Prokhorenko
- Sergey Sargsyan
- Sergey Soloviev
- Sergey Tatarintsev
- Shaik Mohammad Mujeeb
- Shawn McCoy
- Shenhao Wang
- Shihao Zhong
- Shinya Kato
- Shlok Kyal
- Shubham Khanna
- Shveta Malik
- Simon Riggs
- Smolkin Grigory
- Sofia Kopikova
- Song Hongyu
- Song Jinzhou
- Soumyadeep Chakraborty
- Sravan Kumar
- Srinath Reddy
- Stan Hu
- Stepan Neretin
- Stephen Fewer
- Stephen Frost
- Steve Chavez
- Steven Niu
- Suraj Kharage
- Sven Klemm
- Takamichi Osumi
- Takeshi Ideriha
- Tatsuo Ishii
- Ted Yu
- Tels
- Tender Wang
- Teodor Sigaev
- Thom Brown
- Thomas Baehler
- Thomas Krennwallner
- Thomas Munro
- Tim Wood
- Timur Magomedov
- Tobias Wendorff
- Todd Cook
- Tofig Aliev
- Tom Lane
- Tomas Vondra
- Tomasz Rybak
- Tomasz Szypowski
- Torsten Foertsch
- Toshi Harada
- Tristan Partin
- Triveni N
- Umar Hayat
- Vallimaharajan G
- Vasya Boytsov
- Victor Yegorov
- Vignesh C
- Viktor Holmberg
- Vinícius Abrahão
- Vinod Sridharan
- Virender Singla
- Vitaly Davydov
- Vladlen Popolitov
- Vladyslav Nebozhyn
- Walid Ibrahim
- Webbo Han
- Wenhui Qiu
- Will Mortensen
- Will Storey
- Wolfgang Walther
- Xin Zhang
- Xing Guo
- Xuneng Zhou
- Yan Chengpen
- Yang Lei
- Yaroslav Saburov
- Yaroslav Syrytsia
- Yasir Hussain
- Yasuo Honda
- Yogesh Sharma
- Yonghao Lee
- Yoran Heling
- Yu Liang
- Yugo Nagata
- Yuhang Qiu
- Yuki Seino
- Yura Sokolov
- Yurii Rashkovskii
- Yushi Ogiwara
- Yusuke Sugie
- Yuta Katsuragi
- Yuto Sasaki
- Yuuki Fujii
- Yuya Watari
- Zane Duffield
- Zeyuan Hu
- Zhang Mingli
- Zhihong Yu
- Zhijie Hou
- Zsolt Parragi