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I have queries that sporadically take a very long time
Posted by: Stephan Tual
Date: February 21, 2009 04:23PM

Hi, basically my problem is as follow:

Our web server server processes around 24 queries per second. My slow query log is set to track the ones taking longer than 5 seconds. It only picks up maybe 20 queries a day taking longer than that.

The problem is that these query instances take 60+ seconds to run when they run slow, and they cause our server to 'freeze'. It's bizarre, because they are properly indexed and I can execute them manually without any issue. In fact, they are run regularly during the day without any problem, except for these rare instances.

I understand how an improperly indexed query can run slow. I don't understand how an optimized one can run well (read: 10ms) 99.99% of the time , and when running slow, take so long.

Is there a way for me to figure out what's going on?



Edited 1 time(s). Last edit at 02/21/2009 04:25PM by Stephan Tual.

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I have queries that sporadically take a very long time
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