centos man page for rollback_prepared

ROLLBACK 
PREPARED(7)					  PostgreSQL 9.2.7 Documentation				      ROLLBACK PREPARED(7)

NAME
       ROLLBACK_PREPARED - cancel a transaction that was earlier prepared for two-phase commit

SYNOPSIS
       ROLLBACK PREPARED transaction_id

DESCRIPTION
       ROLLBACK PREPARED rolls back a transaction that is in prepared state.

PARAMETERS
       transaction_id
	   The transaction identifier of the transaction that is to be rolled back.

NOTES
       To roll back a prepared transaction, you must be either the same user that executed the transaction originally, or a superuser. But you do
       not have to be in the same session that executed the transaction.

       This command cannot be executed inside a transaction block. The prepared transaction is rolled back immediately.

       All currently available prepared transactions are listed in the pg_prepared_xacts system view.

EXAMPLES
       Roll back the transaction identified by the transaction identifier foobar:

	   ROLLBACK PREPARED 'foobar';

COMPATIBILITY
       ROLLBACK PREPARED is a PostgreSQL extension. It is intended for use by external transaction management systems, some of which are covered
       by standards (such as X/Open XA), but the SQL side of those systems is not standardized.

SEE ALSO
       PREPARE TRANSACTION (PREPARE_TRANSACTION(7)), COMMIT PREPARED (COMMIT_PREPARED(7))

PostgreSQL 9.2.7						    2014-02-17						      ROLLBACK PREPARED(7)