Re: Table Partitioning, Part 1

From: Hannu Krosing <hannu(at)skype(dot)net>
To: Simon Riggs <simon(at)2ndquadrant(dot)com>
Cc: pgsql-hackers(at)postgresql(dot)org, bizgres-general <bizgres-general(at)pgfoundry(dot)org>
Subject: Re: Table Partitioning, Part 1
Date: 2005-05-10 13:44:04
Message-ID: 1115732644.4779.83.camel@fuji.krosing.net
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On T, 2005-05-10 at 16:31 +0300, Hannu Krosing wrote:
> On E, 2005-05-09 at 23:30 +0100, Simon Riggs wrote:

> There are 2 possibly expensive steps:
>
> 1. the conversion to "AND'ed list of simple clauses" (unknown
> complexity)
>
> 2. matching each of "simple" clauses in the and list with all others
> (should be N+(N-1)+(N-2)+..+(1) ~= 2N) complexity)

actually not 2N but (N * ((N-1)/2) , thus 3 clauses need 2+1=3 checks
and 11 clasues need (10+9+..+1) = 55 checks.

--
Hannu Krosing <hannu(at)skype(dot)net>

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