Re: Slow planning time for simple query - Mailing list pgsql-general

From Tom Lane
Subject Re: Slow planning time for simple query
Date
Msg-id 13756.1528305133@sss.pgh.pa.us
Whole thread Raw
In response to Slow planning time for simple query  (Jeremy Finzel <finzelj@gmail.com>)
Responses Re: Slow planning time for simple query  (Jeremy Finzel <finzelj@gmail.com>)
List pgsql-general
Jeremy Finzel <finzelj@gmail.com> writes:
> We have an odd scenario on one of our OLTP systems, which behaves the same
> way on a streamer, of a 700-1000ms planning time for a query like this:

> SELECT *
> FROM table1
> WHERE  source_id IN (SELECT id FROM table2 WHERE customer_id = $1);

Hm.  Is this the first query executed in a session?  If so maybe it's
got something to do with populating caches and other session spin-up
overhead.

Another theory is it's some sort of locking issue.  Turning on
log_lock_waits, and setting deadlock_timeout to say 100ms, would help
in investigating that.

            regards, tom lane


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