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Re: Query Optimization

From: Martin Haltmayer <Martin.Haltmayer_at_d2mail.de>
Date: Wed, 20 Mar 2002 13:42:48 +0100
Message-ID: <3C9883C8.6FAF4ACC@d2mail.de>


What you want is called "star transformation". You can hint it with the /*+ star */ comment.

Martin

Rich Pinder wrote:
>
> Dont know if this list is the proper place to ask this, but here goes:
>
> I've got a select statement that runs SO slowly, and I'm sure it's
> because I'm missing something about select syntax that Oracle uses.
>
> here's a simple description:
> I have very large tables for NAMETABLE, ADDTABLE, AND TELETABLE.
> I have tiny table for SMALLIST.
>
> the sql i use must be interpreted by the optimizer to join all the large
> tables first, then do the sub'select on the very small table.
>
> What I want to do is get the small table processed first (this will
> surely make things run much faster).
>
> heres the select:
>
> select DISTINCT a.name, b.add, c.tele, d.code
> from nametable a, addtable b, teletable c, smallist d
> where d.id = c.id AND
> c.id = b.id AND
> b.id = a.id AND
> b.id2 = a.id2 AND
> c.id IN
> (select id from smallist); <---- this is the small table
>
> Thanks for any thoughts.
>
> rich
Received on Wed Mar 20 2002 - 06:42:48 CST

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