Re: [PERFORM] Long running queries degrade performance

2004-04-17 Thread Christopher Browne
A long time ago, in a galaxy far, far away, [EMAIL PROTECTED] (Mike Nolan) wrote: >> We have a web app with a postgres backend. Most queries have subsecond >> response times through the web even with high usage. Every once in awhile >> someone will run either an ad-hoc query or some other long

Re: [PERFORM] Long running queries degrade performance

2004-04-16 Thread Chris Kratz
On Friday 16 April 2004 5:12 pm, Tom Lane wrote: > Chris Kratz <[EMAIL PROTECTED]> writes: > > ... Or if worse comes to worse to actually kill long running > > processes without taking down the whole db as we have had to do on > > occasion. > > A quick "kill -INT" suffices to issue a query cancel,

Re: [PERFORM] Long running queries degrade performance

2004-04-16 Thread Tom Lane
Chris Kratz <[EMAIL PROTECTED]> writes: > ... Or if worse comes to worse to actually kill long running > processes without taking down the whole db as we have had to do on occasion. A quick "kill -INT" suffices to issue a query cancel, which I think is what you want here. You could also consider

Re: [PERFORM] Long running queries degrade performance

2004-04-16 Thread Chris Kratz
On Friday 16 April 2004 4:25 pm, Mike Nolan wrote: > Given the intermittent nature of the problem and its relative brevity > (5-10 seconds), I don't know whether top offers the granularity needed to > locate the bottleneck. Our long running processes run on the order of multiple minutes (sometimes

Re: [PERFORM] Long running queries degrade performance

2004-04-16 Thread Mike Nolan
> Fairly sure, when it is happening, postgres usually is taking up the top slots > for cpu usage as reported by top. Perhaps there is a better way to monitor > this? Given the intermittent nature of the problem and its relative brevity (5-10 seconds), I don't know whether top offers the granul

Re: [PERFORM] Long running queries degrade performance

2004-04-16 Thread Chris Kratz
Fairly sure, when it is happening, postgres usually is taking up the top slots for cpu usage as reported by top. Perhaps there is a better way to monitor this? The other thing for us is that others talk about disks being the bottleneck whereas for us it is almost always the processor. I expec

Re: [PERFORM] Long running queries degrade performance

2004-04-16 Thread Mike Nolan
> We have a web app with a postgres backend. Most queries have subsecond > response times through the web even with high usage. Every once in awhile > someone will run either an ad-hoc query or some other long running db > process. Are you sure it is postgres where the delay is occurring?

[PERFORM] Long running queries degrade performance

2004-04-16 Thread Chris Kratz
Hello all, My apologies if this is not the right mailing list to ask this question, but we are wondering about general performance tuning principles for our main db server. We have a web app with a postgres backend. Most queries have subsecond response times through the web even with high usa