Re: CREATE INDEX uses INDEX ?

From: Guillaume Lelarge <guillaume(at)lelarge(dot)info>
To: Nicolas Paris <niparisco(at)gmail(dot)com>
Cc: postgres performance list <pgsql-performance(at)postgresql(dot)org>
Subject: Re: CREATE INDEX uses INDEX ?
Date: 2015-03-07 11:56:11
Message-ID: CAECtzeXdOJiyk3r5fuE7X-KSop9KSwL5hDdCK9Pr8uTApsjRow@mail.gmail.com
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Le 7 mars 2015 11:32, "Nicolas Paris" <niparisco(at)gmail(dot)com> a écrit :
>
> Hello,
>
> I wonder if the process of index creation can benefit from other indexes.
>

It cannot.

> EG: Creating a partial index with predicat based on a boolean column,
will use an hypothetic index on that boolean column or always use a seq
scan on all rows ?
>

Nope, it always does a seqscan.

> Goal is to create partial indexes faster.
>
> Explain command does not work with Create index.
>

You cannot use EXPLAIN on most DDL commands.

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