Re: What is faster?

Поиск
Список
Период
Сортировка
От Martijn van Oosterhout
Тема Re: What is faster?
Дата
Msg-id 20010918092503.B25112@svana.org
обсуждение исходный текст
Ответ на Re: What is faster?  (Allan Engelhardt <allane@cybaea.com>)
Список pgsql-general
On Mon, Sep 17, 2001 at 10:05:32PM +0100, Allan Engelhardt wrote:
> Mihai Gheorghiu wrote:
>
> > What runs faster?
> > select   where   timestamp IS NOT NULL
> > or
> > select   where   boolean IS TRUE?
>
> It depends.....  (You knew somebody would say that, didn't you? :-))
>
> If you return a lot of data, then the statement that returns the least
> data is likely to be the fastest.

Except for the fact that IS NOT NULL cannot use an index whereas IS TRUE can
(I beleive, = 't' definitly can).

--
Martijn van Oosterhout <kleptog@svana.org>
http://svana.org/kleptog/
> Magnetism, electricity and motion are like a three-for-two special offer:
> if you have two of them, the third one comes free.

В списке pgsql-general по дате отправления:

Предыдущее
От: "Joe Conway"
Дата:
Сообщение: Re: Practical Cursors
Следующее
От: "Command Prompt, Inc."
Дата:
Сообщение: Re: Practical Cursors