Re: performance with query

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: performance with query
Дата
Msg-id 15037.1245353961@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: performance with query  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Ответы Re: performance with query  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Список pgsql-performance
"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> With all the optimizer options on, and the from_collapse_limit and
> join_collapse_limit values both set to 100, run an EXPLAIN (no
> ANALYZE) on your big problem query.  Let us know how long the EXPLAIN
> runs.  If it gets any errors, copy and paste all available
> information.  (General descriptions aren't likely to get us very far.)
> Since EXPLAIN without ANALYZE only *plans* the query, but doesn't run
> it, it should not take long to do this.

One issue here is that with the collapse limits cranked up to more than
geqo_threshold, he's going to be coping with GEQO's partially-random
plan selection; so whatever he reports might or might not be especially
reflective of day-to-day results.  I'm tempted to ask that he also push
up geqo_threshold.  It's possible that that *will* send the planning
time to the moon; but it would certainly be worth trying, to find out
what plan is produced.

            regards, tom lane

В списке pgsql-performance по дате отправления:

Предыдущее
От: "Kevin Grittner"
Дата:
Сообщение: Re: performance with query
Следующее
От: Peter Alban
Дата:
Сообщение: Re: Strange performance response for high load times