Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!apple!voder!blia!miket
From: miket@blia.sharebase.com (Mike Tossy)
Newsgroups: comp.databases
Subject: Re: how bad is oracle?
Message-ID: <13470@blia.sharebase.com>
Date: 7 Feb 91 17:32:34 GMT
References: <10737@pasteur.Berkeley.EDU> <1991Feb3.182558.14411@oracle.com> <1991Feb6.144339.10316@lgc.com>
Organization: ShareBase Corp, Los Gatos, CA
Lines: 55

In article <1991Feb6.144339.10316@lgc.com>, rubi@lgc.com ( Ernest Rubi) writes:
> In article <9292@cognos.UUCP> nigelc@cognos.UUCP (Nigel Campbell) writes:
> >In article <1991Feb3.182558.14411@oracle.com> jklein@oracle.UUCP (Jonathan Klein) writes:
> >>In article <10737@pasteur.Berkeley.EDU> mao@eden.Berkeley.EDU (Mike Olson) writes:

[stuff deleted]

> >>>here's the question:  i have heard that oracle does not have a query
> >>>optimizer.  i find this surprising.  is it true?

[stuff deleted]

> >>All versions of oracle that I have worked with have had an query optimizer.
> >>
> >>Jonathan Klein
> >
> >Would you like to give a comparison on the merits of the Oracle approach
> >vs say Rdb/Vms,Interbase,Sybase etc especially based on a database where
> >the user has not taken to using physical row,table placement schemes . 
> >Nigel Campbell          Voice: (613) 783-6828                P.O. Box 9707
> >Cognos Incorporated     FAX: (613) 738-0002               3755 Riverside Dr.

[stuff deleted]

> Oracle's syntactically-based optimizer approach permits fine-tuning of the 
> SQL statement for added performance. This advantage, however, is generally 
> lost during ad hoc querying by less sophisticated users since fine-tuning 
> requires a good understanding of the database structure and an appreciation 
> for Oracle's optimizer strategies. The rumor mill has it that Oracle is 
> preparing a statistically-based optimizer. I would not be surprise if this 
> optimizer comes to be regarded as the most effective in the industry.
> ---
> Ernest Rubi			Phone : (713) 579-4789
> Landmark Graphics Corp.		Fax   : (713) 579-4814
> 333 Cypress Run			E-Mail: rubi@lgc.com
> Houston, TX  77094

The ShareBase optimizer (and I think most other statistical based optimizers)
have an over-ride feature.  Given that, it is hard to understand any advantage
for the Oracle approach.  The override feature allows you to explicitly request
a strategy.  The Oracle approach requires that you muck up your SQL query (for
example, with meaningless function calls that prevent the use of some indices.)
Every system ALLOWS fine-tuning of the SQL statement for performance; Oracle 
REQUIRES fine-tuning of the SQL statement for performance.

My opinion: "syntactically-based optimizer" is an oxymoron.

--

	>>>>>>>	The above are only my opinions <<<<<<<<

Mike Tossy					ShareBase Coropration
miket@sharebase.com				14600 Wichester Blvd
(408) 378-7575 ext2200				Los Gatos, CA 95030
	(ShareBase is a subsidiary of Teradata Corportation)