Jeff, Thanks for your response, I did turn the fsync off, no performance improvement. Since the application is a network monring program, data is not critical for us. Marty -----Original Message----- From: Jeff Davis [mailto:pgsql@xxxxxxxxxxx] Sent: Monday, August 21, 2006 5:23 PM To: Marty Jia Cc: pgsql-performance@xxxxxxxxxxxxxx Subject: Re: [PERFORM] How to get higher tps On Mon, 2006-08-21 at 16:45 -0400, Marty Jia wrote: > I'm exhausted to try all performance tuning ideas, like following > parameters > > shared_buffers > fsync By "tuning" fsync, what do you mean? Did you turn it off? If you turned fsync off, that could compromise your data in case of any kind of crash or power failure. However, if you turn fsync off you should much higher TPS on pgbench than you're getting. > Dual Intel Xeon 2.8GHz > 6GB RAM > Linux 2.4 kernel > RedHat Enterprise Linux AS 3 > 200GB for PGDATA on 3Par, ext3 > 50GB for WAL on 3Par, ext3 Does your disk controller have battery-backed writeback cache? How much? > With PostgreSql 8.1.4 > > We don't have i/o bottle neck. > Well, chances are PostgreSQL is waiting for fsync, which means you do have an I/O bottleneck (however, you're not using all of your I/O bandwidth, most likely). Regards, Jeff Davis
