Re: will the planner ever use an index when the condition is <> ?

From: Віталій Тимчишин <tivv00(at)gmail(dot)com>
To: Filip Rembiałkowski <plk(dot)zuber(at)gmail(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org, Roxanne Reid-Bennett <rox(at)tara-lu(dot)com>
Subject: Re: will the planner ever use an index when the condition is <> ?
Date: 2011-12-18 10:41:21
Message-ID: CABWW-d1r9Doya=ntE5U+5o8Hj2W0WuiKvNeYsEyEecaj4mb=fg@mail.gmail.com
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17.12.2011 18:25 пользователь "Filip Rembiałkowski" <plk(dot)zuber(at)gmail(dot)com>
написал:
>
> Normally there is no chance it could work,
> because (a) the planner does not know all possible values of a column,
> and (b) btree indexes cannot search on "not equal" operator.
>

Why so? a<>b is same as (a<b or a>b), so, planner should chech this option.

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