Re: High Planning Time

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