Re: v7.1b4 bad performance
Bruce Momjian <pgman@candle.pha.pa.us>
From: Bruce Momjian <pgman@candle.pha.pa.us>
To: "Schmidt, Peter" <peter.schmidt@prismedia.com>
Cc: "'Tom Lane'" <tgl@sss.pgh.pa.us>, "'Michael Ansley'" <Michael.Ansley@intec-telecom-systems.com>, "'pgsql-admin@postgresql.org'" <pgsql-admin@postgresql.org>
Date: 2001-02-17T04:11:37Z
Lists: pgsql-hackers
> I get ~50 tps for any commit_delay value > 0. I've tried many values in the > range 0 - 999, and always get ~50 tps. commit_delay=0 always gets me ~200+ > tps. > > Yes, I have tried multiple clients but got stuck on the glaring difference > between versions with a single client. The tests that I ran showed the same > kind of results you got earlier today i.e. 1 client/1000 transactions = 10 > clients/100 transactions. > > So, is it OK to use commit_delay=0? commit_delay was designed to provide better performance in multi-user workloads. If you are going to use it with only a single backend, you certainly should set it to zero. If you will have multiple backends committing at the same time, we are not sure if 5 or 0 is the right value. If multi-user benchmark shows 0 is faster, we may change the default. -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026