Re: WAL + SSD = slow inserts? - Mailing list pgsql-performance

From Jeff Janes
Subject Re: WAL + SSD = slow inserts?
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Msg-id CAMkU=1zwM+p_9-Gi_rBXHYfMtEuiGnDYsjhQWq+yiks4b4AbtA@mail.gmail.com
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In response to WAL + SSD = slow inserts?  (Skarsol <skarsol@gmail.com>)
List pgsql-performance
On Thu, Dec 5, 2013 at 7:01 AM, Skarsol <skarsol@gmail.com> wrote:
I'm trying to increase the speed of inserts in a database that is on a not super fast storage system. I have installed a pair of SSDs and placed pg_xlog on them but am still getting inserts that take up to a second to complete, with .3 seconds being about average. Iostat doesn't show the SSDs stressed at all, and changing synchronous_commit doesn't seem to affect it one way or the other. Where would I look next for what could be causing the delay?

What are you inserting?  At 0.3 seconds per, I'm guessing this is not just a simple single-row insert statement.
 
Are you IO bound or CPU bound?

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