Re: [SQL] Question on indexes

From: Alvaro Herrera <alvherre(at)commandprompt(dot)com>
To: Emil Rachovsky <zsevgymko(at)yahoo(dot)com>
Cc: pgsql-sql(at)postgresql(dot)org, pgsql-general(at)postgresql(dot)org
Subject: Re: [SQL] Question on indexes
Date: 2005-12-19 16:31:33
Message-ID: 20051219163133.GC9980@surnet.cl
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Emil Rachovsky wrote:
>
> Hi,
> Can anyone show me a simple way of creating an index
> in PostGre like that:
> create index indName on someTable(someIntColumn DESC)
> ?

Not using that particular syntax, but you can do that if you create the
appropiate operator classes. Note that if you want to use btree index
on a single column, you don't need to have a descending index, because
btree indexes can be scanned in either direction. The opclass trick is
only needed if you want to have a multicolumn index. (I guess in the
other access methods it doesn't make much sense to think of descending
indexes.)

--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.

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