Slide 17 of 21
Notes:
- 2 bit transaction flag - committed, aborted, or in
progress
- Instantaneous Transaction abortion and Crash Recovery
- Time travel- Current records on magnetic disk, Historical
records on optical disk jukebox or other tertiary storage
devices or WORM -write-once read many
- Vacuum Cleaner-Started out as a background function,
under heavy load, it would not run
- Stable Memory-If present, no need to commit pages written
by transaction to disk.
- WAL-Write Ahead Log cannot, must process log to restore
database, log in a different format so it cannot be
queries for historical data.
