Re: how could select id=xx so slow?

[Craig Ringer <ringerc@xxxxxxxxxxxxx>]

On 07/12/2012 01:10 PM, Yan Chunlu wrote:

after check out the wiki page Maciek mentioned, turns out that heavy connection also burden the disk hardly.

looks like I am in the vicious circle:

1, slow query cause connection blocked so the client request more connection. 

2, more connection cause high disk io and make even the simplest query slow and block.

While true, you can often control this by making sure you don't completely overload your hardware, queuing queries instead of running them all at once.

You may still discover that your hardware can't cope with the workload in that your queues may just keep on getting deeper or time out. In that case, you certainly need to optimise your queries, tune your database, and/or get bigger hardware.

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Craig Ringer