Re: pg_standby and build farm

On Wed, 2006-12-27 at 20:09 +0000, Simon Riggs wrote:

> The reason for the -m option was performance. Recovery is I/O-bound,
> with 50% of the CPU it does use coming from IsRecordValid() - which is
> where the CRC checking takes place. (I can add an option to recover
> without CRC checks, if anyone wants it, once I've rejigged the option
> parsing for recovery.conf.)

Make that 70% of the CPU, for long running recoveries, but the CPU only
gets as high as 20% on my tests, so still I/O bound.

> Should be able to use hard links, i.e. ln -f -s /archivepath/%f %p
> instead. I'll test that tomorrow then issue a new version.

The ln works, and helps, but not that much. I'll remove the -m option
and replace it with an -l option. Must be careful to use the -f option.

The majority of the I/O comes from writing dirty buffers, so enabling
the bgwriter during recovery would probably be more helpful.

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