Re: Access Paths: Will these produce equivalent results?

From: Mikito Harakiri <mikharakiri_at_ywho.com>
Date: Fri, 9 May 2003 16:01:03 -0700
Message-ID: <1xWua.6$5X4.39@news.oracle.com>

"--CELKO--" <71062.1056_at_compuserve.com> wrote in message news:c0d87ec0.0305091404.3e4f92b3_at_posting.google.com...
> >> Is SQLServer guaranteed to produce the same results, no matter
> what's in the tables? <<
>
> It should.
>
> Oracle is still a lousy product without a very good optimizer, so it
> probably just plows thru the clauses in the order they are given,
> without making an attempt to see if a group column predicate can be
> moved into the WHERE clause, so that you do not have to build all of
> the groups, then retain only a few of them.

That is a blank statement which is easy to prove wrong. Consider equivalently rewritten query where redundant "having" clause is transformed into inline view. The predicate is pushed inside group by in that case! Received on Fri May 09 2003 - 18:01:03 CDT