SAVEPOINT(7)		PostgreSQL 9.2.24 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.

NOTES
       Use ROLLBACK TO SAVEPOINT (ROLLBACK_TO_SAVEPOINT(7)) to rollback to a
       savepoint. Use RELEASE SAVEPOINT (RELEASE_SAVEPOINT(7)) 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.

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 9.2.24		  2017-11-06			  SAVEPOINT(7)