Re: Some queries starting to hang

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: Some queries starting to hang
Дата
Msg-id 23915.1149541591@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: Some queries starting to hang  (Andrew Sullivan <ajs@crankycanuck.ca>)
Ответы Re: Some queries starting to hang  (Chris Beecroft <CBeecroft@PrO-Unlimited.com>)
Re: Some queries starting to hang  (Simon Riggs <simon@2ndquadrant.com>)
Список pgsql-performance
Andrew Sullivan <ajs@crankycanuck.ca> writes:
> On Mon, Jun 05, 2006 at 04:07:19PM -0400, Tom Lane wrote:
>> I'm wondering about out-of-date or nonexistent ANALYZE stats, missing
>> custom adjustments of statistics target settings, etc.

> But even the nested loop shouldn't be a "never returns" case, should
> it?  For 1800 rows?

Well, it's a big query.  If it ought to take a second or two, and
instead is taking an hour or two (1800 times the expected runtime), that
might be close enough to "never" to exhaust Chris' patience.  Besides,
we don't know whether the 1800 might itself be an underestimate (too bad
Chris didn't provide EXPLAIN ANALYZE results).  The hash plan will scale
to larger numbers of rows much more gracefully than the nestloop ...

            regards, tom lane

В списке pgsql-performance по дате отправления:

Предыдущее
От: Andrew Sullivan
Дата:
Сообщение: Re: vacuuming problems continued
Следующее
От: Josh Berkus
Дата:
Сообщение: Re: How to force Postgres to use index on ILIKE