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))

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