Re: Simple query takes a long time on win2K - Mailing list pgsql-general

From Lincoln Yeoh
Subject Re: Simple query takes a long time on win2K
Date
Msg-id 5.2.1.1.1.20050323224520.03e5b5e0@localhost
Whole thread Raw
In response to Simple query takes a long time on win2K  ("A. Mous" <a.mous@shaw.ca>)
Responses Re: Simple query takes a long time on win2K
Re: Simple query takes a long time on win2K
List pgsql-general
They are quite different hardware.

How long does it take for the _first_ time you do the query on the Celeron
machine? The first time. Wait until everything has started up first and the
machine is quiescent.

How long does it take for the _second_ and _third_ times?

Do the same for all the machines.

Are the drives on the machine very different?

How about you analyze the disks on each machine and compare how fragmented
the database files are on the various machines?

128MB RAM is not very much for a Win2K machine. Not very far from swapping.

Win2K pro or Win2K server? Performance optimized for server or
desktop/applications?

Regards,
Link.

At 02:57 AM 3/23/2005 -0700, A. Mous wrote:

>Hi,
>
>I have a table with about 1500 records.  My query is very basic: SELECT *
>FROM foo;
>
>With postgres 8.0.1 on Win XP (Celeron 2400, 500MB RAM) it returns the
>results in about 80ms.  The same query on the same database, tested on three
>different win2k machines all running 8.0.1, takes roughly 4 seconds.  Win2K
>machines are as follows:
>
>1) PIII 800, 256MB RAM
>2) Celeron 400, 128MB RAM
>3) PII 233, 128MB RAM
>
>All machines are currently using the default settings upon install.  I've
>tried adjusting shared_buffers and work_mem but nothing seems to make any
>difference.
>
>EXPLAIN ANALYZE on WinXP machine gives:
>
>Seq Scan on foo  (cost=0.00..65.71 rows=1471 width=95) (actual
>time=0.000..0.000 rows=1472 loops=1)
>
>Same on #3 Win2K machine gives:
>
>Seq Scan on foo  (cost=0.00..40.72 rows=1472 width=95) (actual
>time=0.000..80.000 rows=1472 loops=1)
>
>All queries are executed locally on the server.  Can anyone please explain
>the profound performance difference here (which appear to be related to the
>OS)?
>
>Much thanks in advance!
>
>
>---------------------------(end of broadcast)---------------------------
>TIP 9: the planner will ignore your desire to choose an index scan if your
>       joining column's datatypes do not match



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