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Forcing using index instead of sequential scan?

From: <robin(dot)c(dot)smith(at)bt(dot)com>
To: <pgsql-performance(at)postgresql(dot)org>
Subject: Forcing using index instead of sequential scan?
Date: 2006-07-21 10:40:33
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-performance
I have been testing the performance of PostgreSQL using the simple tool
found at however I have found that all the
queries it run execute with sequential scans. The website where the code
runs has examples of the execution plan using indexes.

When I disable the sequential plan query 0 and query 1 run faster ( ) by
using the indexes as suggested by the website.

I have tried increasing the effective_cache_size and reducing the
random_page_cost to try and force the optimiser to use the index but it
always uses the sequential scan.

What is the best way to force the use of indexes in these queries?
Currently testing with version 8.1.4.


Robin Smith

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London EC1A 7AJ

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Subject: Re: Forcing using index instead of sequential scan?
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