SAVEPOINT(7) PostgreSQL 15.7 Documentation SAVEPOINT(7)
NAME
SAVEPOINT - define a new savepoint within the current transaction
SYNOPSIS
SAVEPOINT savepoint_name
DESCRIPTION
SAVEPOINT establishes a new savepoint within the current transaction.
A savepoint is a special mark inside a transaction that allows all
commands that are executed after it was established to be rolled back,
restoring the transaction state to what it was at the time of the
savepoint.
PARAMETERS
savepoint_name
The name to give to the new savepoint. If savepoints with the same
name already exist, they will be inaccessible until newer
identically-named savepoints are released.
NOTES
Use ROLLBACK TO to rollback to a savepoint. Use RELEASE SAVEPOINT to
destroy a savepoint, keeping the effects of commands executed after it
was established.
Savepoints can only be established when inside a transaction block.
There can be multiple savepoints defined within a transaction.
EXAMPLES
To establish a savepoint and later undo the effects of all commands
executed after it was established:
BEGIN;
INSERT INTO table1 VALUES (1);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (2);
ROLLBACK TO SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (3);
COMMIT;
The above transaction will insert the values 1 and 3, but not 2.
To establish and later destroy a savepoint:
BEGIN;
INSERT INTO table1 VALUES (3);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (4);
RELEASE SAVEPOINT my_savepoint;
COMMIT;
The above transaction will insert both 3 and 4.
To use a single savepoint name:
BEGIN;
INSERT INTO table1 VALUES (1);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (2);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (3);
-- rollback to the second savepoint
ROLLBACK TO SAVEPOINT my_savepoint;
SELECT * FROM table1; -- shows rows 1 and 2
-- release the second savepoint
RELEASE SAVEPOINT my_savepoint;
-- rollback to the first savepoint
ROLLBACK TO SAVEPOINT my_savepoint;
SELECT * FROM table1; -- shows only row 1
COMMIT;
The above transaction shows row 3 being rolled back first, then row 2.
COMPATIBILITY
SQL requires a savepoint to be destroyed automatically when another
savepoint with the same name is established. In PostgreSQL, the old
savepoint is kept, though only the more recent one will be used when
rolling back or releasing. (Releasing the newer savepoint with RELEASE
SAVEPOINT will cause the older one to again become accessible to
ROLLBACK TO SAVEPOINT and RELEASE SAVEPOINT.) Otherwise, SAVEPOINT is
fully SQL conforming.
SEE ALSO
BEGIN(7), COMMIT(7), RELEASE SAVEPOINT (RELEASE_SAVEPOINT(7)),
ROLLBACK(7), ROLLBACK TO SAVEPOINT (ROLLBACK_TO_SAVEPOINT(7))
PostgreSQL 15.7 2024 SAVEPOINT(7)
Generated by dwww version 1.15 on Sat Jun 29 02:20:31 CEST 2024.