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From: Joel Reymont <joelr1@gmail.com>
In-Reply-To: <op.vuri6d2keorkce@apollo13>
Mime-Version: 1.0 (iPhone Mail 8H7)
Date: Sat, 30 Apr 2011 19:14:31 +0100
Message-ID: <7582830307139292886@unknownmsgid>
Subject: Re: stored proc and inserting hundreds of thousands of rows
To: Pierre C <lists@peufeu.com>
Cc: "pgsql-performance@postgresql.org" <pgsql-performance@postgresql.org>
Content-Type: text/plain; charset=ISO-8859-1

I'm calculating distance between probability vectors, e.g. topics that
a document belongs to and the topics of an ad.

The distance function is already a C function. Topics are float8[150].

Distance is calculated against all documents in the database so it's
arable scan.

Sent from my comfortable recliner

On 30/04/2011, at 19:04, Pierre C <lists@peufeu.com> wrote:

>
> If you want to search by geographical coordinates, you could use a gist index which can optimize that sort of things (like retrieving all rows which fit in a box).