Please cc the list so others can help. How large is the database? What indexes are on the tables you're inserting into? What speed is the drive? Since it's a single SCSI drive I'm assuming it's only 10k RPM, which means the theoretical maximum you can hit is 160 transfers per second. At 40 inserts per second (I'm assuming each insert is it's own transaction), you're already at 40 WAL operations per second, minimum. Plus whatever traffic you have to the data tables. Your biggest win would be to batch those inserts together into transactions, if possible. If not, the commit_delay settings might help you out. There may be some further gains to be had by tweaking the background writer settings; it might be too aggressive in your application. That update statement could also be causing a lot of activity, depending on what it's doing. -- Jim C. Nasby, Sr. Engineering Consultant jnasby@xxxxxxxxxxxxx Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 -----Original Message----- From: Kumarselvan S [mailto:kumar@xxxxxxxxx] Sent: Wed 8/9/2006 11:33 PM To: Jim Nasby Subject: RE: [BUGS] BUG #2567: High IOWAIT Yes , it is not a Bug. Here the some Info abt the Hardware It has an SCSI Drive. It an dell made quad processor machine. The changes to Postgresql.conf 1. max_connections =50 2. shared buffer = 30000 3. Temp buffer 20000 Regards, Kumar -----Original Message----- From: Jim C. Nasby [mailto:jnasby@xxxxxxxxxxxxx] Sent: Thursday, August 10, 2006 3:57 AM To: kumarselvan Cc: pgsql-performance@xxxxxxxxxxxxxx Subject: Re: [BUGS] BUG #2567: High IOWAIT This isn't a bug; moving to pgsql-performance. On Tue, Aug 08, 2006 at 08:42:02AM +0000, kumarselvan wrote: > i have installed the postgres as mentioned in the Install file. it is a 4 > cpu 8 GB Ram Machine installed with Linux Enterprise version 3. when i am > running a load which will perfrom 40 inserts persecond on 2 tables and 10 > updates per 10seconds on differnt table IOWait on avg going upto 70% due to > which i am not able to increase the load. Is there is any other way to > install the postgres on multiprocessor machine.. can any one help me on > this... You haven't given us nearly enough information. What kind of hardware is this? RAID? What changes have you made to postgresql.conf? -- Jim C. Nasby, Sr. Engineering Consultant jnasby@xxxxxxxxxxxxx Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461 quad
