On Wed, Oct 8, 2008 at 12:08 PM, Kevin Grittner <Kevin.Grittner@xxxxxxxxxxxx> wrote: > > If the problem is checkpoints (which seems likely but far from a sure > thing based on the information provided), aggressive background writer > setting might be your best bet under 8.2.X. To solve similar problems > we had to go to the following, although many on these lists feel that > settings this aggressive are rarely needed, so use at your own risk. > > #bgwriter_delay = 200ms > bgwriter_lru_percent = 20.0 > bgwriter_lru_maxpages = 200 > bgwriter_all_percent = 10.0 > bgwriter_all_maxpages = 600 I've tuned an 8.2 server with settings similar to this, and it made a world of difference on smoothing out performance. Note that bgwriter tends to use cpu and memory bandwidth up, so avoid going crazy on it. > Even better would be to go to the latest revision of the 8.3 release, > which at this writing is 8.3.4. In that release PostgreSQL spreads > out the work of a checkpoint to minimize this problem. Seconded. A lot of hard work went into making the bgwriter much easier to adjust, and much less likely to even need adjusting in 8.3.
