Re: 7.4 - FK constraint performance

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: 7.4 - FK constraint performance
Дата
Msg-id 27696.1076647796@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: 7.4 - FK constraint performance  (ow <oneway_111@yahoo.com>)
Список pgsql-sql
ow <oneway_111@yahoo.com> writes:
> --- Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Can't see how we optimize your case without pessimizing more-common cases.

> I think other RDBMSs simply use preset value instead of partial table
> scan when there's not enough stat info. Might be a better way.

The problem here cannot be described as "not enough stat info".  The
available stats are complete and they point very strongly to the
conclusion that searches in the large table should be seqscans.
To do otherwise would be folly in general, even if it happens to
be the correct thing in this particular example.
        regards, tom lane


В списке pgsql-sql по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: 7.4 - FK constraint performance
Следующее
От: "Kumar"
Дата:
Сообщение: Re: How to avoid nulls while writing string for dynamic query