Re: wal_checksum = on (default) | off

On Thu, 2007-01-04 at 10:00 -0500, Tom Lane wrote:
> "Simon Riggs" <simon@2ndquadrant.com> writes:
> > In this thread, I outlined an idea for reducing cost of WAL CRC checking
> > http://archives.postgresql.org/pgsql-hackers/2006-10/msg01299.php
> > wal_checksum = on (default) | off
>
> This still seems awfully dangerous to me.

Understood.

> > Recovery can occur with/without same setting of wal_checksum, to avoid
> > complications from crashes immediately after turning GUC on.
>
> Surely not.  Otherwise even the "on" setting is not really a defense.

Only when the CRC is exactly zero, which happens very very rarely.

--
  Simon Riggs
  EnterpriseDB   http://www.enterprisedb.com