Undoes any changes made since the last COMMIT or ROLLBACK.
ROLLBACK [ WORK ]
ROLLBACK ends a logical unit of work (transaction) and undoes all changes made to the database during this transaction. A transaction is the database work done between COMMIT or ROLLBACK statements on one database connection.
Closes all cursors not opened WITH HOLD.
Releases locks held by the transaction issuing the ROLLBACK.
Must be connected to the database.
