thread-index: AccPUda13D7qlX1QSUqva+EKrS0RjQ==
Message-ID: <456625C5.1050601@enterprisedb.com>
Date: Thu, 23 Nov 2006 22:50:45 +0000
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From: "Heikki Linnakangas" <heikki@enterprisedb.com>
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To: "Gopal" <gopal@getmapping.com>
Cc: <pgsql-performance@postgresql.org>
Subject: Re: Postgres scalability and performance on windows
References: <A5DE6132B8D812419321747E42710E2204C05F@EXCHANGE01.gm.local>
In-Reply-To: <A5DE6132B8D812419321747E42710E2204C05F@EXCHANGE01.gm.local>
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Gopal wrote:

> Functions : Simple coordinate reprojection and intersection query +
> inner join of table1 and table2.
> 
> I think I have all the right indexes defined and indeed the performance
> for  queries under low loads is fast.

Can you do a EXPLAIN ANALYZE on your queries, and send the results back 
to the list just to be sure?

> SQL server caches all the data in memory which is making it faster(uses
> about 1.2GB memory- which is fine).
> 
> But postgres has everything spread across 10-15 processes, with each
> process using about 10-30MB, not nearly enough to cache all the data and
> ends up doing a lot of disk reads.

I don't know Windows memory management very well, but let me just say 
that it's not that simple.

> I've read that postgres depends on OS to cache the files, I wonder if
> this is not happenning on windows.

Using the Task Manager, or whatever it's called these days, you can see 
how much memory is used for caching.

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com