From: | "Thomas T(dot) Thai" <tom(at)minnesota(dot)com> |
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To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | PostgreSQL General <pgsql-general(at)postgresql(dot)org> |
Subject: | Re: mnogosearch -- pgsql seem so slow, please help me find out why |
Date: | 2001-01-12 16:58:27 |
Message-ID: | Pine.NEB.4.21.0101121054570.18450-100000@ns01.minnesota.com |
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Lists: | pgsql-general |
On Fri, 12 Jan 2001, Tom Lane wrote:
> "Thomas T. Thai" <tom(at)minnesota(dot)com> writes:
> > 'select * from url' from psql monitor took 59 seconds.
>
> How big is the table? Your EXPLAIN mentions 99256 rows, but I can't
> tell if that stat is up-to-date or not.
it is 99256. i don't think it's that big of a table is it? typically the
query under mnogo takes less than a second, at most a couple seconds but
not 50+ secs.
maybe Hermit has some input as he runs it for postgresql.org's search.
> A select like that is going to be pretty much all data transfer: read
> the disk blocks, format the data values, send 'em to the frontend.
> There's hardly anything that Postgres can do to optimize or pessimize
> it. You might shave a few milliseconds by using a binary cursor (to
> avoid formatting the integer values into ASCII) but probably not a lot.
>
> If you've done a whole lot of UPDATEs/DELETEs on the table since your
> last VACUUM, then reading empty disk blocks might be costing you some
> time.
i did vacuum analyze.
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