Date: Fri, 17 Mar 2006 22:32:53 +0300
From: Evgeny Gridasov <eugene@i-free.ru>
To: Dan Harris <fbsd@drivefaster.net>
Cc: pgsql-performance@postgresql.org
Subject: Re: Help optimizing a slow index scan
Message-Id: <20060317223253.38c0e6b9.eugene@i-free.ru>
In-Reply-To: <441ADB88.9010701@drivefaster.net>
References: <4419DB50.10404@drivefaster.net>
 <4419DC1C.9070806@drivefaster.net>
	<684362e10603161915x431c6b08t@mail.gmail.com>
	<441AD702.9020508@drivefaster.net>
	<441ADB88.9010701@drivefaster.net>
Organization: i-free.ru
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit

Try contrib/btree_gist.
I've tried that one, but for my case it didn't help much.
The performance was almost equal or even slower than built-in btree.

On Fri, 17 Mar 2006 08:53:44 -0700
Dan Harris <fbsd@drivefaster.net> wrote:

> Dan Harris wrote:
> > Markus Bertheau wrote:
> >> Have you tried using a GIST index on lat & long? These things are
> >> meant for two-dimensional data, whereas btree doesn't handle
> >> two-dimensional data that well. How many rows satisfy either of the
> >> long / lat condition?
> >>
> >>  
> >>>     
> > According to the analyze, less than 500 rows matched.  I'll look into 
> > GIST indexes, thanks for the feedback.
> >
> > -Dan
> >
> > ---------------------------(end of broadcast)---------------------------
> > TIP 2: Don't 'kill -9' the postmaster
> 
> When I try to create a GIST index, I get the following error:
> 
> create index eventgeo_lat_idx on eventgeo using GIST (lat);
> 
> ERROR:  data type double precision has no default operator class for 
> access method "gist"
> HINT:  You must specify an operator class for the index or define a 
> default operator class for the data type.
> 
> I'm not sure what a "default operator class" is, exactly..
> 
> -Dan
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 5: don't forget to increase your free space map settings
> 


-- 
Evgeny Gridasov
Software Engineer 
I-Free, Russia