Locks Associated with Other Operations - TARA/ABU

Teradata also uses the following locks.

Build Operation Exclusive Utility Lock

A build operation places an exclusive utility lock on databases where all tables are being built. Locks are applied only to the tables that are being built.

Checkpoint Operation Transaction Locks

The CHECKPOINT statement places transaction locks rather than utility (HUT) locks. Transaction locks are automatically released when the checkpoint operation terminates. A checkpoint operation places:

A write lock on the journal table for which checkpoints are being set.

Read locks on the data tables that may contribute change images to the journal table for which checkpoints are being set.

The operation places these locks and then writes the checkpoint. After the operation writes the checkpoint, Teradata ARC releases the locks.

Note: If a journal is marked for later archiving using CHECKPOINT with the SAVE option, the AMP places an access lock on the data tables instead of a read lock.

Rollback/Rollforward Operations Exclusive and Read Utility Locks

Rollback and rollforward operations place these utility (HUT) locks:

Exclusive locks on the tables to be recovered.

A read utility lock on the journal table that is input to the recovery operation.

A journal table with a read utility lock can still log change images. The read utility lock on the journal table does prevent concurrent Teradata ARC statements, such as DELETE JOURNAL.

Delete Journal Operations Write Lock

DELETE JOURNAL places transaction locks, not utility (HUT) locks. When the operation finishes, Teradata Archive/Recovery Utility automatically releases all transaction locks.

DELETE JOURNAL places a write lock on the journal table to be deleted. DELETE JOURNAL deletes only the saved journal, therefore the active portion of the journal can still log change images during the delete operation. Other archive or recovery operations are not permitted.