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
