redbookcover.gif (13955 bytes) Readings in Database Systems, 3rd Edition

Stonebraker & Hellerstein, eds.

Summary, Cont.

Checkpointing: A quick way to limit the amount of log to scan on recovery.

Recovery works in 3 phases:

Analysis: Forward from checkpoint.
Redo: Forward from oldest recLSN.
Undo: Backward from end to first LSN of oldest Xact alive at crash.

Upon Undo, write CLRs.

Redo “repeats history”: Simplifies the logic!

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1998, Joseph M. Hellerstein.  Last modified 08/17/98.
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