Checkpoints
Problem - Prevent Restart from scanning back to the start of the log
A checkpoint is a procedure to limit the amount of work for Restart
Commit-consistent checkpointing
- Stop accepting new update, commit, and abort operations
- Make list of [active transaction, pointer to last log record]
- Flush all dirty pages
- Append a checkpoint record to log; include the list
- Resume normal processing
Database and log are now mutually consistent