Re: Using ctid column changes plan drastically

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: Using ctid column changes plan drastically
Дата
Msg-id 22819.1343145325@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: Using ctid column changes plan drastically  (Thomas Kellerer <spam_eater@gmx.net>)
Ответы Re: Using ctid column changes plan drastically  (Thomas Kellerer <spam_eater@gmx.net>)
Список pgsql-performance
Thomas Kellerer <spam_eater@gmx.net> writes:
> Tom Lane, 24.07.2012 16:23:
>> IIRC, type tid doesn't have any hash support.

> So the "bad" plan is expected?

Joins on tid columns just aren't supported very well at the moment.
Partly that's from lack of round tuits, and partly it's because it
doesn't seem all that wise to encourage people to use them.  There
are gotchas if any of the rows receive concurrent updates.

FWIW, it might be helpful to cast this as a NOT EXISTS rather than
NOT IN subquery.

            regards, tom lane

В списке pgsql-performance по дате отправления:

Предыдущее
От: Maciek Sakrejda
Дата:
Сообщение: Re: Geoserver-PostGIS performance problems
Следующее
От: Thomas Kellerer
Дата:
Сообщение: Re: Using ctid column changes plan drastically