Re: Adding additional index causes 20,000x slowdown for certain select queries - postgres 9.0.3

Поиск
Список
Период
Сортировка
От Kevin Grittner
Тема Re: Adding additional index causes 20,000x slowdown for certain select queries - postgres 9.0.3
Дата
Msg-id 4D820911020000250003BA47@gw.wicourts.gov
обсуждение исходный текст
Ответ на Re: Adding additional index causes 20,000x slowdown for certain select queries - postgres 9.0.3  (Timothy Garnett <tgarnett@panjiva.com>)
Ответы Re: Adding additional index causes 20,000x slowdown for certain select queries - postgres 9.0.3  (Timothy Garnett <tgarnett@panjiva.com>)
Список pgsql-performance
Timothy Garnett <tgarnett@panjiva.com> wrote:

> We'd still be interested in other suggestions for convincing the
> query planner not to pick the bad plan in this case

You could try boosting cpu_tuple_cost.  I've seen some evidence that
the default number is a bit low in general, so it wouldn't
necessarily be bad to try your whole load with a higher setting.  If
that doesn't work you could set it for the one query.  If that
setting alone doesn't do it, you could either decrease both page
cost numbers or multiply all the cpu numbers (again, probably
boosting cpu_tuple_cost relative to the others).

-Kevin

В списке pgsql-performance по дате отправления:

Предыдущее
От: Timothy Garnett
Дата:
Сообщение: Re: Adding additional index causes 20,000x slowdown for certain select queries - postgres 9.0.3
Следующее
От: Timothy Garnett
Дата:
Сообщение: Re: Adding additional index causes 20,000x slowdown for certain select queries - postgres 9.0.3