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Checkpoint - CKPT
Signals DBWn to perform checkpoint
Updates all data files and control files
- Checkpoint has been taken
- Checkpoint data
- e.g. Log sequence numbers
Notes:
The CKPT process initiates the process of checkpointing by signaling DBWn to start writing modified blocks in the buffer cache to disk. Checkpoints are initiated when a log switch occurs. It can also be forced with the ALTER SYSTEM CHECKPOINT command.
When the checkpoint is complete, CKPT then updates the control file and the headers of the data files to record that a checkpoint has occurred.