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Re: Memory allocation for postmaster service...

From: "Kevin Schroeder" <kschroeder(at)mirageworks(dot)com>
To: "Mike Leahy" <mgleahy(at)fes(dot)uwaterloo(dot)ca>,<pgsql-cygwin(at)postgresql(dot)org>
Subject: Re: Memory allocation for postmaster service...
Date: 2003-09-17 22:09:30
Message-ID: 05df01c37d68$5e801930$0200a8c0@WORKSTATION (view raw or flat)
Thread:
Lists: pgsql-cygwin
Sometimes if you put a column in the WHERE part of the query that is in one
of the indexes, even you aren't using it, sometimes that will force use of
an index.  Or what you can try is if you have multiple parts in your WHERE
statement (e.g where column1 = 1 and column2 = 2) try creating an index that
has both of those in there.

There are a number of different things like that which you can use to trick
PostgreSQL into using an index.  I've had the same problems where PostgreSQL
won't use an index but the methods I've stated above have worked for me in
the past.

Kevin


----- Original Message ----- 
From: Mike Leahy
To: 'Kevin Schroeder'
Sent: Wednesday, September 17, 2003 4:56 PM
Subject: RE: [CYGWIN] Memory allocation for postmaster service...


I've got spatial indexes for the spatial tables, as well as relevant
standard indexes on other tables (but which I'm not using in this specific
case).  It helped a little, but not much.  The EXPLAIN ANALYZE never
revealed much to me...in fact, the queries almost never choose to use the
indexes over a straight sequential search...as far as I know, there's no way
to force it to use the indexes.

Mike

-----Original Message-----
From: pgsql-cygwin-owner(at)postgresql(dot)org
[mailto:pgsql-cygwin-owner(at)postgresql(dot)org] On Behalf Of Kevin Schroeder
Sent: September 17, 2003 2:49 PM
To: pgsql-cygwin(at)postgresql(dot)org
Subject: Re: [CYGWIN] Memory allocation for postmaster service...

Memory allocation could be the issue, but first try looking at your indexes.
That almost always solves any speed issues for me.  If you haven't yet, try
EXPLAIN ANALYZE.

Kevin
----- Original Message ----- 
From: Mike Leahy
To: pgsql-cygwin(at)postgresql(dot)org
Sent: Wednesday, September 17, 2003 1:44 PM
Subject: [CYGWIN] Memory allocation for postmaster service...

I'm just wondering if it's possible to increase the allocation of memory to
the postmaster service.  I'm running PosgreSQL with PostGIS, and sometimes
running a map query on multiple objects from Mapserver can take a very long
time with the CPU running at 100%.  I'm hoping increasing the memory
allocation would improve the performance...

Kind regards,
Mike


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