Purpose of Checkpoints

A checkpoint operation has two primary purposes.

• Decreases the amount of time required for database recovery, because it provides a more up-to-date database image on which recovery can begin.

• Makes a portion of the transaction log unneeded for any future database recovery operation, typically allowing one or more transaction log files to be deleted.

Both of these functions are very important to TimesTen applications. The reduction in recovery time is important, as the amount of a transaction log needed to recover a database has a direct impact on the amount of downtime seen by an application after a system failure. The removal of unneeded transaction log files is important because it frees file system space that can be used for new transaction log files. If these files were never purged, they would eventually consume all available space in the transaction log files directory, causing database operations to fail due to log space exhaustion.