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Checkpoint

The last moment a database's tables were known to be fully on disk. Recovery replays the log from there.

Taught in Chapter 24: Durability.

More from the same chapter

• Durable: A write that no crash, power cut or failover can lose once it was acknowledged.
• fsync: Asking the operating system to flush a file's writes to disk and waiting until it has.
• Point-in-time recovery: Restoring a backup plus its log up to a chosen moment, such as just before a bad delete.
• RPO and RTO: How much recent data may be lost in a failure, and how long recovery may take.
• Synchronous commit: Acknowledging a write only once its log entry is flushed to disk.
• Synchronous replication: Acknowledging a write only once at least one replica has it.
• Write-ahead log: An append-only log of changes, flushed before a write is acknowledged and replayed after a crash.