On 06/06/2018 09:59 AM, Jeremy Finzel wrote:
Hello -
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);
The actual execution time is sub-ms.
I am trying to sort out the various references to times so could you:
Show the EXPLAIN ANALYZE?
and ?
psql> \timing
psql> SELECT *
FROM table1
WHERE source_id IN (SELECT id FROM table2 WHERE customer_id = $1);
We initially thought maybe catalog bloat? But we were able to reindex
all of the highly churned catalog tables, and I even did VACUUM FULL on
pg_attribute and pg_statistic, to no avail.
There are no custom settings for pg_attribute for the given tables either.
Interestingly, the problem goes away on a SAN snapshot of the target system.
Any ideas of what else we could try? A PL function that caches the
query plan works, but that is just a workaround.
Thanks!
Jeremy
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
