Database Management Systems · Recovery

Write-ahead logging and recovery

Writing what you're about to change to a log before touching the actual page, so a crash can still recover the right state.

Also known as: WAL, redo undo recovery, crash recovery.

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• Transactions and ACID properties: The four guarantees (atomicity, consistency, isolation, durability) that make a transaction feel like one indivisible unit.

Leads to

• ARIES recovery algorithm: The specific three-phase algorithm (analysis, redo, undo) real databases use to recover using the write-ahead log.

Related topics

• ARIES recovery algorithm: The specific three-phase algorithm (analysis, redo, undo) real databases use to recover using the write-ahead log.
• Storage and file organization: How rows actually get laid out into pages and files on disk.