From: | Marc Lavergne <mlavergne-pub(at)richlava(dot)com> |
---|---|
To: | pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Upgrading to 7.2 |
Date: | 2002-02-14 17:50:13 |
Message-ID: | 3C6BF8D5.8060302@richlava.com |
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Lists: | pgsql-hackers |
I have that book too (page 168 in my revision) definitely looks like an
error. Indexes cannot be applied to aggregate functions since the data
rowset is only defined in the context of a given query. So, until
functionality is added to maintain an index based on a SQL query (view
or what not) rather than a table, this just ain't gonna happen. :)
Chris Field wrote:
> Thanks for responding, I am thinking it might be fairly beneficial to
> upgrade.
>
>
>>Ummm, max() is an aggregate function, how can you create an index on
>>it?
>>
>
> In the postgresSQL Essential Reference by Barry Stinson it specifically
> has a index topic on functional indexes, with the given example being
> " CREATE INDEX max_payroll_idx ON payroll (MAX(salary)); "
> so either the book was a waste of money, or this is a 7.2 specific
> feature.
>
>
--
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Marc P. Lavergne [wk:650-576-7978 hm:407-648-6996]
Senior Software Developer
Global Knowledge Management
Worldwide Support Technologies
Openwave Systems Inc.
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