Updates in Databases: Logging and Recovery
Review: The ACID properties
Passing the ACID Test
Cascading Aborts
Recoverable Schedules
Motivation
Assumptions
Handling the Buffer Pool
More on Steal and Force
Basic Idea: Logging
Write-Ahead Logging (WAL)
WAL & the Log
Log Records
Other Log-Related State
Normal Execution of an Xact
Checkpointing
The Big Picture: What’s Stored Where
Simple Transaction Abort
Abort, cont.
Transaction Commit
Crash Recovery: Big Picture
Recovery: The Analysis Phase
Recovery: The REDO Phase
Recovery: The UNDO Phase
Example of Recovery
Example: Crash During Restart!
Additional Crash Issues
Summary of Logging/Recovery
Summary, Cont.
Email: susan@cis.upenn.edu