Re: Seqscan rather than Index

From: Bruno Wolff III
Subject: Re: Seqscan rather than Index
Date: ,
Msg-id: 20041218043918.GA20619@wolff.to
(view: Whole thread, Raw)
In response to: Re: Seqscan rather than Index  ("Steinar H. Gunderson")
Responses: Re: Seqscan rather than Index  ("Steinar H. Gunderson")
List: pgsql-performance

Tree view

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.


pgsql-performance by date:

From: Stan Y
Date:
Subject: Monitor CPU time per transaction?
From: "Steinar H. Gunderson"
Date:
Subject: Re: Seqscan rather than Index