Blocking Checkpoints

Blocking checkpoints obtain an exclusive lock on the database for a portion of the checkpoint operation, which blocks all access to the database during that time.

The resulting checkpoint image contains all committed transactions prior to the time the checkpoint operations acquired the exclusive lock on the database. Because no transactions can be active while the database lock is held, no modifications made by in-progress transactions are included in the checkpoint image.

In TimesTen, an application uses the ttCkptBlocking built-in procedure to request a blocking checkpoint. The actual checkpoint is delayed until the requesting transaction commits or rolls back. If a blocking checkpoint is requested for a database for which both checkpoint files are already up to date then the checkpoint request is ignored.