| From: | "Steinar H(dot) Gunderson" <sgunderson(at)bigfoot(dot)com> |
|---|---|
| To: | pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Seqscan rather than Index |
| Date: | 2004-12-17 23:55:48 |
| Message-ID: | 20041217235548.GD16149@uio.no |
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| Lists: | pgsql-performance |
On Fri, Dec 17, 2004 at 05:02:29PM -0600, Frank Wiles wrote:
> It depends more on your disk IO than the processor. Counting isn't
> processor intensive, but reading through the entire table on disk
> is. I've also seen a huge difference between select count(*) and
> select count(1) in older versions, haven't tried it on a recent
> version however.
Like I said, all in cache, so no disk IO. count(*) and count(1) give me
identical results. (BTW, I don't think this is a count problem, it's a
"sequential scan" problem -- I'm just trying to find out if this is natural
or not, ie. if this is just something I have to expect in a relational
database, even with no I/O.)
/* Steinar */
--
Homepage: http://www.sesse.net/
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