On 2014-10-06 14:19:39 +0300, Heikki Linnakangas wrote: > On 10/06/2014 04:42 AM, Michael Paquier wrote: > >On Fri, Oct 3, 2014 at 9:51 PM, Heikki Linnakangas <hlinnakan...@vmware.com> > >wrote: > >>So I now have a refactoring patch ready that I'd like to commit (the > >attached two patches together), but to be honest, I have no idea why the > >second patch is so essential to performance. > >Thanks. I did some more tests with master, master+patch1, master+patch1+CRC > >refactoring, but I am not able to see any performance difference with > >pgbench (--no-vacuum, -t) and the test suite you provided, just some noise > >that barely changed performance. > > Thanks for the confirmation. I'm really going crazy with benchmarking this. > Sometimes I see a big difference, the next day it's gone.
A usual suspect for this is turbo mode and power control. It often already helps to disable the latter to get much more reproducible benchmark results. > Barring objections, I'll commit this, and then continue benchmarking the > second patch with the WAL format and API changes. I'd like to have a look at it beforehand. I've not yet really looked, but on a quick readthrough XLogInsertRecData() staying in xlog.c doesn't make me happy... Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers