On Sep 18, 2014 9:32 PM, Andrew Dunstan <andrew@xxxxxxxxxxxx> wrote: > > > On 09/18/2014 03:09 PM, Mkrtchyan, Tigran wrote: > > > > ----- Original Message ----- > >> From: "Josh Berkus" <josh@xxxxxxxxxxxx> > >> To: pgsql-performance@xxxxxxxxxxxxxx > >> Sent: Thursday, September 18, 2014 7:54:24 PM > >> Subject: Re: 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. > > > > > > > > > This is when you dig out tools like perf, maybe. Do you have a better suggestions ? > > cheers > > andrew -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
