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ROLLBACK TO SAVEPOINT

Name

ROLLBACK TO SAVEPOINT -- roll back to a savepoint

Synopsis

ROLLBACK [ WORK | TRANSACTION ] TO [ SAVEPOINT ] savepoint_name

Description

Roll back all commands that were executed after the savepoint was established. The savepoint remains valid and can be rolled back to again later, if needed.

ROLLBACK TO SAVEPOINT implicitly destroys all savepoints that were established after the named savepoint.

Parameters

savepoint_name

The savepoint to roll back to.

Notes

Use RELEASE SAVEPOINT to destroy a savepoint without discarding the effects of commands executed after it was established.

Specifying a savepoint name that has not been established is an error.

Cursors have somewhat non-transactional behavior with respect to savepoints. Any cursor that is opened inside the savepoint is not closed when the savepoint is rolled back. If a cursor is affected by a FETCH command inside a savepoint that is later rolled back, the cursor position remains at the position that FETCH left it pointing to (that is, FETCH is not rolled back). A cursor whose execution causes a transaction to abort is put in a can't-execute state, so while the transaction can be restored using ROLLBACK TO SAVEPOINT, the cursor can no longer be used.

Examples

To undo the effects of the commands executed after my_savepoint was established:

ROLLBACK TO SAVEPOINT my_savepoint;

Cursor positions are not affected by savepoint rollback:

BEGIN;

DECLARE foo CURSOR FOR SELECT 1 UNION SELECT 2;

SAVEPOINT foo;

FETCH 1 FROM foo;
 ?column? 
----------
        1

ROLLBACK TO SAVEPOINT foo;

FETCH 1 FROM foo;
 ?column? 
----------
        2

COMMIT;

Compatibility

The SQL:2003 standard specifies that the key word SAVEPOINT is mandatory, but EnterpriseDB and Oracle allow it to be omitted. SQL:2003 allows only WORK, not TRANSACTION, as a noise word after ROLLBACK. Also, SQL:2003 has an optional clause AND [ NO ] CHAIN which is not currently supported by EnterpriseDB. Otherwise, this command conforms to the SQL standard.

 
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