Re: Seqscan rather than Index

От: Bruno Wolff III
Тема: Re: Seqscan rather than Index
Дата: ,
Msg-id: 20041218043918.GA20619@wolff.to
(см: обсуждение, исходный текст)
Ответ на: Re: Seqscan rather than Index  ("Steinar H. Gunderson")
Ответы: Re: Seqscan rather than Index  ("Steinar H. Gunderson")
Список: pgsql-performance

Скрыть дерево обсуждения

Seqscan rather than Index  (Jon Anderson, )
 Re: Seqscan rather than Index  (Tom Lane, )
 Re: Seqscan rather than Index  (David Brown, )
  Re: Seqscan rather than Index  (Richard Huxton, )
   Re: Seqscan rather than Index  (Greg Stark, )
    Re: Seqscan rather than Index  (Tom Lane, )
     Re: Seqscan rather than Index  (Greg Stark, )
      Re: Seqscan rather than Index  (Tom Lane, )
    Re: Seqscan rather than Index  ("Steinar H. Gunderson", )
     Re: Seqscan rather than Index  ("Steinar H. Gunderson", )
      Re: Seqscan rather than Index  (Frank Wiles, )
       Re: Seqscan rather than Index  ("Steinar H. Gunderson", )
       Re: Seqscan rather than Index  (Tom Lane, )
        Re: Seqscan rather than Index  (Frank Wiles, )
     Re: Seqscan rather than Index  (Bruno Wolff III, )
      Re: Seqscan rather than Index  ("Steinar H. Gunderson", )

On Fri, Dec 17, 2004 at 22:56:27 +0100,
  "Steinar H. Gunderson" <> wrote:
>
> I'm a bit unsure -- should counting ~3 million rows (no OIDs, PG 7.4,
> everything in cache, 32-byte rows) take ~3500ms on an Athlon 64 2800+?

It doesn't seem totally out of wack. You will be limited by the memory
bandwidth and it looks like you get something on the order of a few
hundred references to memory per row. That may be a little high, but
it doesn't seem ridiculously high.


В списке pgsql-performance по дате сообщения:

От: Stan Y
Дата:
Сообщение: Monitor CPU time per transaction?
От: "Steinar H. Gunderson"
Дата:
Сообщение: Re: Seqscan rather than Index