----- Original Message ----- > From: "Josh Berkus" <j...@agliodbs.com> > To: pgsql-performance@postgresql.org > Sent: Thursday, September 18, 2014 7:54:24 PM > Subject: Re: [PERFORM] postgres 9.3 vs. 9.4 > > On 09/18/2014 08:09 AM, Mkrtchyan, Tigran wrote: > >>> 9.4beta2: > >>> > > > >> > ... > >> > > >>> > > 0.957854 END; > >>> > > > >> > > >> > Looks like IO. > > Postgres internal IO? May be. We get 600MB/s on this SSDs. > > While it's possible that this is a Postgres issue, my first thought is > that the two SSDs are not actually identical. The 9.4 one may either > have a fault, or may be mostly full and heavily fragmented. Or the Dell > PCIe card may have an issue.
We have tested both SSDs and they have identical IO characteristics and as I already mentioned, both databases are fresh, including filesystem. > > You are using "scale 1" which is a < 1MB database, and one client and 1 > thread, which is an interesting test I wouldn't necessarily have done > myself. I'll throw the same test on one of my machines and see how it does. this scenario corresponds to our use case. We need a high transaction rate per for a single client. Currently I can get only ~1500 tps. Unfortunately, posgtress does not tell me where the bottleneck is. Is this is defensively not the disk IO. Thanks for the help, Tigran. > > -- > Josh Berkus > PostgreSQL Experts Inc. > http://pgexperts.com > > > -- > Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-performance > -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
