Crash recovery is the PostgreSQL subsystem that saves us, should the server crash or fail as part of a system crash.
It's good to understand a little about it and to do what we can to control it in our favor.
Crash recovery is the PostgreSQL subsystem that saves us, should the server crash or fail as part of a system crash.
It's good to understand a little about it and to do what we can to control it in our favor.
If PostgreSQL crashes, there will be a message in the server log with the severity level set to PANIC. PostgreSQL will immediately restart and attempt to recover using the transaction log or Write-Ahead Log (WAL).
The WAL consists of a series of files written to the pg_wal subdirectory of the PostgreSQL data directory. Each change made to the database is recorded first in WAL, hence the name write-ahead log, as a synonym of transaction log. When a transaction...