Subject: Re: Help with optimizing a sql statement
From: Rafael Martinez <r.m.guerrero@usit.uio.no>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-performance@postgresql.org
In-Reply-To: <5731.1139527320@sss.pgh.pa.us>
References: <1139497827.25608.1014.camel@bbking.uio.no>
	<5731.1139527320@sss.pgh.pa.us>
Content-Type: text/plain
Organization: University of Oslo
Date: Fri, 10 Feb 2006 00:36:34 +0100
Message-Id: <1139528194.19758.18.camel@linux.site>
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On Thu, 2006-02-09 at 18:22 -0500, Tom Lane wrote:
> Rafael Martinez Guerrero <r.m.guerrero@usit.uio.no> writes:
> > WHERE ((ACL_2.RightName = 'OwnTicket')) 
> > AND ((CachedGroupMembers_4.MemberId = Principals_1.id)) 
> > AND ((Groups_3.id = CachedGroupMembers_4.GroupId)) 
> > AND ((Principals_1.Disabled = '0') or (Principals_1.Disabled = '0')) 
> > AND ((Principals_1.id != '1')) 
> > AND ((main.id = Principals_1.id)) 
> > AND  ( (    ACL_2.PrincipalId = Groups_3.id AND ACL_2.PrincipalType =
> > 'Group' AND (   Groups_3.Domain = 'SystemInternal' OR Groups_3.Domain =
> > 'UserDefined' OR Groups_3.Domain = 'ACLEquivalence')) OR ( (
> > (Groups_3.Domain = 'RT::Queue-Role' ) )  AND Groups_3.Type
> > =ACL_2.PrincipalType) )
> > AND (ACL_2.ObjectType = 'RT::System' OR (ACL_2.ObjectType = 'RT::Queue')
> > ) 
> 
> Are you sure this WHERE clause really expresses your intent?  It seems
> awfully oddly constructed.  Removing the redundant parens and clarifying
> the layout, I get
> 
[............]

This is an application that we have not programmed, so I am not sure
what they are trying to do here. I will contact the developers. Tomorrow
I will try to test some of your suggestions.

> BTW, what PG version is this?  It looks to me like it's doing some
> manipulations of the WHERE clause that we got rid of a couple years ago.
> If this is 7.4 or older then you really ought to be thinking about an
> update.
> 

We are running 7.4.8 in this server and will upgrade to 8.0.6 in a few
weeks.

Thanks.
-- 
Rafael Martinez, <r.m.guerrero@usit.uio.no>
Center for Information Technology Services
University of Oslo, Norway

PGP Public Key: http://folk.uio.no/rafael/