ttCkpt

Description

Performs a non-blocking checkpoint. The blocking checkpoints are described in "ttCkptBlocking". A checkpoint operation is used to make a record of the current state of the data store on disk and to purge transaction log files. A non-blocking checkpoint does not require any locks on the data store.

Applications should checkpoint data stores periodically either by setting the background checkpointing attributes (CkptFrequency and CkptLogVolume) or by explicitly calling this procedure.

By default, TimesTen performs background checkpoints at regular intervals.

In the case that your application attempts to perform a checkpoint operation while a backup is in process, the backup waits until the checkpoint finishes. Regardless of whether the checkpoint is a background checkpoint or an application-requested checkpoint, the behavior is:

• If a backup or checkpoint is running and you try to do a backup, it will wait for the running backup or checkpoint to finish.

• If a backup or checkpoint is running and you try to do a checkpoint, it will not wait. It will return an error right away.

To turn off background checkpointing, set CkptFrequency=0 and CkptLogVolume=0.

This procedure can be called asynchronously to any other application running on the data store.

When a data store crashes, and the checkpoints on disk are non-blocking checkpoints, TimesTen uses the log to recover.

Required privilege

This procedure requires the ADMIN privilege.

Syntax

ttCkpt()

Parameters

ttCkpt has these optional parameters:

Result set

ttCkpt returns no results.

Example

CALL ttCkpt();

Notes

For a description of checkpoints, see "Transaction Management and Recovery" in Oracle TimesTen In-Memory Database Operations Guide.

See also

ttCkptBlocking
ttCkptConfig
ttCkptHistory