On 14/09/2007, Peter Childs <[EMAIL PROTECTED]> wrote: > > > > On 13/09/2007, Greg Smith <[EMAIL PROTECTED]> wrote: > > > > > > Every time the all scan writes a buffer that is frequently used, that > > write has a good chance that it was wasted because the block will be > > modified again before checkpoint time. Your settings are beyond regular > > > > aggressive and into the hyperactive terrority where I'd expect such > > redundant writes are happening often. I'd suggest you try to move > > toward > > dropping bgwriter_all_percent dramatically from its current setting and > > see how far down you can go before it starts to introduce blocks at > > checkpoint time. With bgwriter_delay set to 1/4 the default, I would > > expect that even 5% would be a high setting for you. That may be a more > > dramatic change than you want to make at once though, so lowering it in > > that direction more slowly (perhaps drop 5% each day) and seeing whether > > things improve as that happens may make more sense. > > > > > Are you suggesting that reducing bgwriter_delay and bg_writer_percent > would reduce the time spent doing commits? > > I get quite a few commits that take over 500ms (the point when i start > logging queries). I always thought oh just one of those things but if they > can be reduced by changing a few config variables that would be great. I'm > just trying to workout what figures are worth trying to see if I can reduce > them. > > From time to time I get commits that take 6 or 7 seconds but not all the > time. > > I'm currently working with the defaults. > > Peter Childs >
Hmm Always read the manual, Increase them from the defaults....... Peter.
