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_save-
       point(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 Post-
       greSQL,  the old savepoint is kept, though only the more recent one will be used when rolling back or releasing. (Releas-
       ing the newer savepoint will cause the older one to again become accessible to ROLLBACK TO SAVEPOINT  and  RELEASE  SAVE-
       POINT.)  Otherwise, SAVEPOINT is fully SQL conforming.

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



SQL - Language Statements                                  2011-09-22                                               SAVEPOINT(7)