O'Reilly logo

PostgreSQL 9 Administration Cookbook - Second Edition by Simon Riggs, Gianni Ciolli, Hannu Krosing, Gabriele Bartolini

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Understanding and controlling crash recovery

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.

How to do it…

If PostgreSQL crashes, there will be a message in the server log with the severity level of 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_xlog 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 commits, the default—and ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required