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 ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
