Re: merge join killing performance

Поиск
Список
Период
Сортировка
От Scott Marlowe
Тема Re: merge join killing performance
Дата
Msg-id AANLkTikOp1XVFS1O8j9IiAz95Ihf5Ag9DQvpCSeGwA4G@mail.gmail.com
обсуждение исходный текст
Ответ на Re: merge join killing performance  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-performance
On Thu, May 20, 2010 at 8:28 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Scott Marlowe <scott.marlowe@gmail.com> writes:
>> So, Tom, so you think it's possible that the planner isn't noticing
>> all those nulls and thinks it'll just take a row or two to get to the
>> value it needs to join on?
>
> Could be.  I don't have time right now to chase through the code, but
> that sounds like a plausible theory.

K.  I think I'll try an index on that field "where not null" and see
if that helps.

В списке pgsql-performance по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: merge join killing performance
Следующее
От: David Jarvis
Дата:
Сообщение: Re: Optimize date query for large child tables: GiST or GIN?