Berkeley DB: DB->truncate
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++

DB->truncate |

`

    #include <db.h>

    int
    DB->truncate(DB *db,
        DB_TXN *txnid, u_int32_t *countp, u_int32_t flags);

Description: DB->truncate

The DB->truncate method empties the database, discarding all records it contains. The number of records discarded from the database is returned in countp.

When called on a database configured with secondary indices using the DB->associate method, the DB->truncate method truncates the primary database and all secondary indices. A count of the records discarded from the primary database is returned.

It is an error to call the DB->truncate method on a database with open cursors.

The DB->truncate method returns a non-zero error value on failure and 0 on success.

Parameters
countp

- The countp parameter references memory into which the number of records discarded from the database is copied.

flags

- The flags parameter is currently unused, and must be set to 0.

txnid

- If the operation is part of an application-specified transaction, the txnid parameter is a transaction handle returned from DB_ENV->txn_begin; if the operation is part of a Berkeley DB Concurrent Data Store group, the txnid parameter is a handle returned from DB_ENV->cdsgroup_begin; otherwise NULL. If no transaction handle is specified, but the operation occurs in a transactional database, the operation will be implicitly transaction protected.

Errors

The DB->truncate method may fail and return one of the following non-zero errors:

DB_LOCK_DEADLOCK

- A transactional database environment operation was selected to resolve a deadlock.

DB_LOCK_NOTGRANTED

- A Berkeley DB Concurrent Data Store database environment configured for lock timeouts was unable to grant a lock in the allowed time.

EINVAL

- If there are open cursors in the database; or if an invalid flag value or parameter was specified.

Class DB
See Also Databases and Related Methods`

Copyright (c) 1996,2008 Oracle. All rights reserved.