Re: Slow planning time for simple query

2018-06-06 18:59 GMT+02:00 Jeremy Finzel <finzelj(at)gmail(dot)com>:

> 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.
>
> 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.
>

more times I seen similar issue based on bloated indexes on table - pg in
planning time detect min max from possible indexes

Regards

Pavel

> Thanks!
> Jeremy
>