Index not used with or condition

From: Antony Paul <antonypaul24(at)gmail(dot)com>
To: pgsql-performance(at)postgresql(dot)org
Subject: Index not used with or condition
Date: 2005-02-07 09:07:15
Message-ID: 2989532e05020701073638ca4c@mail.gmail.com
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Hi all,
I am facing a strange problem when I run EXPLAIN against a table
having more than 100000 records. The query have lot of OR conditions
and when parts of the query is removed it is using index. To analyse
it I created a table with a single column, inserted 100000
records(random number) in it created index and run a query which
returns 1 record which have no or condition and it was using index. I
added an OR conditon and is using sequential scan. I set the
enable_seqscan to off. I ran the tests again and is using index scan.
So which one I have to use. Is this any bug in Explain.

rgds
Antony Paul.

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