On Wed, Jun 6, 2018 at 12:12 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
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
I have run it over and over with no improvement in the planning time, so I don't thing it's first in session-related. I can only make it faster with a pl function so far.
We have log_lock_waits on and nothing shows, and turning down deadlock_timeout also doesn't do anything.