Re: High Planning Time - Mailing list pgsql-performance

From Albe Laurenz
Subject Re: High Planning Time
Date
Msg-id A737B7A37273E048B164557ADEF4A58B537D51D9@ntex2010i.host.magwien.gv.at
Whole thread Raw
In response to High Planning Time  (Phil S <pjsanders@gmail.com>)
Responses Re: High Planning Time  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
Phil S wrote:
> I am running Postgresql on a Windows Server 2008 server. I have noticed that queries have very high
> planning times now and then. Planning times go down for the same query immediately after the query
> runs the first time, but then go up again after if the query is not re-run for 5 minutes or so.
> 
> I am not able to find any specific information in the documentation that would explain the issue or
> explains how to address it, so am asking for advice here.
> 
> Here is an example.
> 
> explain analyze
> select * from message
> limit 1
> 
> "Limit  (cost=0.00..0.44 rows=1 width=1517) (actual time=0.009..0.009 rows=1 loops=1)"
> "  ->  Seq Scan on message  (cost=0.00..28205.48 rows=64448 width=1517) (actual time=0.007..0.007
> rows=1 loops=1)"
> "Planning time: 3667.361 ms"
> "Execution time: 1.652 ms"
> 
> As you can see the query is simple and does not justify 3 seconds of planning time. It would appear
> that there is an issue with my configuration but I am not able to find anything that looks out of
> sorts in the query planning configuration variables. Any advice about what I should be looking for to
> fix this would be appreciated.

This is odd.

Could you profile the backend during such a statement to see where the time is spent?

Yours,
Laurenz Albe

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