RE: Re[2]: More on Subquery Madness
- From: "Justin Cave" <justin@xxxxxxxxxxx>
- To: <jonathan@xxxxxxxxxxx>, "Justin Cave" <justin@xxxxxxxxxxx>
- Date: Mon, 27 Sep 2004 12:22:52 -0600
How can both be true? If the SQL language does not allow you to specify the
proper relational logic, how can the optimizer be faulted for improperly
guessing at the developer's intention?
Arguably, in fact, Oracle does allow you to specify the proper relational
logic through the use of the NO_MERGE hint. Not the prettiest option,
certainly, but it does seem to provide the necessary extension to SQL's
vocabulary.
Justin Cave
Distributed Database Consulting, Inc.
http://www.ddbcinc.com/askDDBC
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Jonathan Gennick
Sent: Monday, September 27, 2004 2:16 PM
To: Justin Cave
Cc: Oracle-L Freelists
Subject: Re[2]: More on Subquery Madness
Monday, September 27, 2004, 1:25:50 PM, Justin Cave (justin@xxxxxxxxxxx)
wrote:
JC> Reading Date's two replies, it seems that he reaches the opposite
conclusion
JC> in the later discussion-- SQL is unable to express certain relational
JC> algebra concepts properly-- than he did originally-- Oracle's optimizer
is
JC> behaving incorrectly.
I suspect he would say that both are true :-)
Best regards,
Jonathan Gennick --- Brighten the corner where you are
http://Gennick.com * 906.387.1698 * mailto:jonathan@xxxxxxxxxxx
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Monday, September 27, 2004, 1:25:50 PM, Justin Cave (justin@xxxxxxxxxxx)
wrote:
JC> Reading Date's two replies, it seems that he reaches the opposite
conclusion
JC> in the later discussion-- SQL is unable to express certain relational
JC> algebra concepts properly-- than he did originally-- Oracle's optimizer
is
JC> behaving incorrectly. I don't see him say that he has changed his mind,
JC> though... Am I missing some subtlety here?
JC> Justin Cave
JC> Distributed Database Consulting, Inc.
JC> http://www.ddbcinc.com/askDDBC
JC> -----Original Message-----
JC> From: oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx]
JC> On Behalf Of Jonathan Gennick
JC> Sent: Monday, September 27, 2004 9:00 AM
JC> To: Oracle-L Freelists
JC> Subject: More on Subquery Madness
JC> Chris Date surprised me by writing some more on the topic:
JC> http://www.dbdebunk.com/page/page/1409199.htm
JC> x
JC> I actually found his follow-up here more enlightening than
JC> his first round of thoughts. It's a good, thought-provoking
JC> read.
JC> Best regards,
JC> Jonathan Gennick --- Brighten the corner where you are
JC> http://Gennick.com * 906.387.1698 * mailto:jonathan@xxxxxxxxxxx
JC> Join the Oracle-article list and receive one
JC> article on Oracle technologies per month by
JC> email. To join, visit
JC> http://five.pairlist.net/mailman/listinfo/oracle-article,
JC> or send email to Oracle-article-request@xxxxxxxxxxx and
JC> include the word "subscribe" in either the subject or body.
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