Re: Hints (Was: Index Tuning Features)

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: Hints (Was: Index Tuning Features)
Дата
Msg-id 21792.1160701758@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: Hints (Was: Index Tuning Features)  (Casey Duncan <casey@pandora.com>)
Ответы Re: Hints (Was: Index Tuning Features)  ("Andrew Dunstan" <andrew@dunslane.net>)
Re: Hints (Was: Index Tuning Features)  (Josh Berkus <josh@agliodbs.com>)
Список pgsql-hackers
Casey Duncan <casey@pandora.com> writes:
> Yes, but it may be much more efficient for the human to tell the  
> computer than for the computer to introspect things. Take, for  
> example, ndisinct as data grows large.

Yeah, an override estimate for a column's ndistinct seems a perfect
example of the sort of statistical hint that I'd be in favor of having.
We have also talked about solving the multi-column statistics problem
(which, at its core, is "which combinations of columns are worth
accumulating stats for?" --- you can't possibly store stats for every
combination!) by having what would amount to hints from the DBA saying
"keep stats for these combinations".
        regards, tom lane


В списке pgsql-hackers по дате отправления:

Предыдущее
От: "Andrew Dunstan"
Дата:
Сообщение: Re: ./configure argument checking
Следующее
От: "Andrew Dunstan"
Дата:
Сообщение: Re: Hints (Was: Index Tuning Features)