Re: Functional Indexes

From: Frank Bax <fbax(at)sympatico(dot)ca>
To: <pgsql-sql(at)postgresql(dot)org>
Subject: Re: Functional Indexes
Date: 2003-07-15 18:06:06
Message-ID: 5.2.1.1.0.20030715140305.037ed940@pop6.sympatico.ca
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The two functions do not group data the same way, so a common index is not
possible.
urlhost would put pgsql.org and pgsql.com close together.
urltld would but pgsql.com and xyz.com close together.

Frank

At 01:36 PM 7/15/03, David Olbersen wrote:

>Hello all,
>
>I have a function (urlhost) which finds the 'host' portion of a URL. In
>the case of http://www.foobar.com/really/long/path/to/a/file it returns
>"www.foobar.com".
>
>I also have a function (urltld) which returns the TLD of a URL. In the
>case of http://www.foobar.com/really/long/path/to/a/file it returns ".com"
>(the leading dot is OK).
>
>urltld uses urlhost to do it's job (how should be apparent).
>
>Now the question: is there a single index I can create that will be used
>when my WHERE clause contains either urlhost or urltld? I could create
>two functional indexes, but that seems a bit silly to me.
>
>Any thoughts?
>
>--------------------------
>David Olbersen
>iGuard Engineer
>St. Bernard Software
>11415 West Bernardo Court
>San Diego, CA 92127
>1-858-676-2277 x2152
>
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