On 02/19/2013 07:15 PM, Scott Marlowe wrote: > On Tue, Feb 19, 2013 at 4:24 PM, Josh Berkus <josh@xxxxxxxxxxxx> wrote: >> ... then you'll see checkpoint "stalls" and spread checkpoint will >> actually make them worse by making the stalls longer. > > Wait, if they're spread enough then there won't be a checkpoint, so to > speak. Are you saying that spreading them out means that they still > kind of pile up, even with say a completion target of 1.0 etc? I'm saying that spreading them makes things worse, because they get intermixed with the fsyncs for the WAL and causes commits to stall. I tried setting checkpoint_completion_target = 0.0 and throughput got about 10% better. I'm beginning to think that checkpoint_completion_target should be 0.0, by default. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
