From: Steinar H. Gunderson <sgunderson@bigfoot.com>
To: pgsql-performance@postgresql.org
Subject: Re: Performace comparison of indexes over timestamp fields
Date: Tue, 22 May 2007 14:43:20 +0200
Message-ID: <20070522124320.GA24779@uio.no> (raw)
In-Reply-To: <88daf38c0705220539q5807d2c2t1f20a03922bf8d33@mail.gmail.com>
References: <4652C846.4020801@andromeiberica.com>
<88daf38c0705220539q5807d2c2t1f20a03922bf8d33@mail.gmail.com>
On Tue, May 22, 2007 at 02:39:33PM +0200, Alexander Staubo wrote:
> PostgreSQL uses B-tree indexes for scalar values. For an expression
> such as "t between a and b", I believe it's going to match both sides
> of the table independently (ie., t >= a and t <= b) and intersect
> these subsets. This is inefficient.
A B-tree index can satisfy range queries such as this.
> You should get better performance by mapping timestamps to a
> one-dimensional plane and indexing them using GiST. GiST implements an
> R-tree-like structure that supports bounding-box searches.
You may be thinking of interval overlaps?
/* Steinar */
--
Homepage: http://www.sesse.net/
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To: pgsql-performance@postgresql.org
Cc: sgunderson@bigfoot.com
Subject: Re: Performace comparison of indexes over timestamp fields
In-Reply-To: <20070522124320.GA24779@uio.no>
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