Postgres Pro
Downloads
Home   >   mailing lists

Re: If an index is based on 3 columns will a query using two of the columns utilize the index? - Mailing list pgsql-general

From Michael Fuhr
Subject Re: If an index is based on 3 columns will a query using two of the columns utilize the index?
Date
Msg-id 20050912141845.GA34597@winnie.fuhr.org
Whole thread Raw
In response to Re: If an index is based on 3 columns will a query using two of the columns utilize the index?  ("Reid Thompson" <Reid.Thompson@ateb.com>)
List pgsql-general
Tree view 
On Mon, Sep 12, 2005 at 10:05:36AM -0400, Reid Thompson wrote:
> Alvaro Herrera wrote:
> > Note that if your example query used the columns (lname, dob),
> > the answer would be "no."
>
> Why is that? In order to use an index, does the query have to utilize
> the 'first' element of the index?

In released versions of PostgreSQL, yes.  Version 8.1 will remove
that restriction.

--
Michael Fuhr

pgsql-general by date:

Previous
From: "Reid Thompson"
Date:
Subject: Re: If an index is based on 3 columns will a query using two of the columns utilize the index?
Next
From: Alvaro Herrera
Date:
Subject: Re: If an index is based on 3 columns will a query using two of the columns utilize the index?