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SAVEPOINT(7)                     SQL Commands                     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 estab-
       lished.

       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 estab-
       lished. 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 will cause the older one to again become accessible to ROLL-
       BACK TO SAVEPOINT and RELEASE SAVEPOINT.)  Otherwise, SAVEPOINT is fully SQL conforming.

SEE ALSO
       BEGIN [begin(7)], COMMIT [commit(7)], RELEASE SAVEPOINT [release_savepoint(7)], ROLLBACK  [rollback(7)],  ROLL-
       BACK TO SAVEPOINT [rollback_to_savepoint(7)]



SQL - Language Statements         2014-02-17                      SAVEPOINT(7)