Hi Greg, Am Mittwoch 28 November 2007 schrieb Greg Smith: > On Sat, 24 Nov 2007, Peter Bauer wrote: > > top shows that the CPUs are at least 80% idle most of the time so i > > think there is an I/O bottleneck. > > top also shows that you're never waiting for I/O which is usually evidence > there isn't an I/O bottleneck. You passed along most of the right data, > but some useful additional things to know are: > > -Actual brand/model of SCSI controller > -Operating system > -What time interval the vmstat and iostat information you gave were > produced at. here are the hardware specs: 2x POWEREDGE 2850 - XEON 3.0GHZ/2MB, 800FSB 2048MB SINGLE RANK DDR2 73 GB SCSI-Disk , 15.000 rpm, UL PERC4E/DI DC ULTRA320 SCSI RAID, 256MB Its Debian sarge with kernel 2.4.26.050719-686 #1 SMP. vmstat and iostat were running with 1 second intervals. > I agree with Scott that checkpoints should be considered as a possibility > here. I'd suggest you set checkpoint_warning to a high value so you get a > note in the logs every time one happens, then see if those happen at the > same time as your high load average. More on that topic and how to adjust > the background writer if that proves to be the cause of your slowdown is > at http://www.westnet.com/~gsmith/content/postgresql/chkp-bgw-83.htm > > -- > * Greg Smith gsmith@xxxxxxxxxxxxx http://www.gregsmith.com Baltimore, MD > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Have you searched our list archives? > > http://archives.postgresql.org/ thank you, Peter -- Peter Bauer APUS Software G.m.b.H. A-8074 Raaba, Bahnhofstrasse 1/1 Email: peter.bauer@xxxxxxxxxx Tel: +43 316 401629 24 Fax: +43 316 401629 9 ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
