Checkpoint Operations

A checkpoint operation synchronizes the current state of the TimesTen in-memory database with the state in the latest on disk checkpoint file.

A checkpoint operation writes any regions of the in-memory database that have been changed since the last checkpoint operation. Checkpoint operations alternate between two checkpoint files so that there is always the latest and latest – 1 checkpoint images available for recovery. Once the checkpoint completes, TimesTen purges the related transaction log files (which are now a part of the checkpoint) as they are no longer required.

By default, TimesTen automatically performs background checkpoints at regular intervals. Checkpointing may generate a large amount of I/O activity and have a long processing time depending on the size of the database and the number of database changes since the most recent checkpoint.

Note:

Applications can programmatically initiate checkpoint operations. See Setting and Managing Checkpoints.

The following sections describe checkpoint operations and how you can manage them:

• Purpose of Checkpoints

• Usage of Checkpoint Files

• Types of Checkpoints

• Setting and Managing Checkpoints