Re: Seq Scans when index expected to be used

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От Stephan Szabo
Тема Re: Seq Scans when index expected to be used
Дата
Msg-id 20031129093428.R75231@megazone.bigpanda.com
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Ответ на Seq Scans when index expected to be used  (ow <oneway_111@yahoo.com>)
Список pgsql-sql
On Sat, 29 Nov 2003, ow wrote:

> Am trying to find duplicate values in a large table (about 80M records).
> Somehow, none of the two (2) queries (see below) is using the index "I_bca"
> that, I believe, should've been used.

As a side note, to help determine if it should be used, you probably want
explain analyze not just explain. In general the index is only going to
help you if the sort is very expensive, not for the initial scan (where
the seq scan is generally faster).


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