Sounds fun Cary.... Wish it were being web casted! Robert G. Freeman Oracle ACE Ask me about on-site Oracle Training! RMAN, DBA, Tuning, you name it! Author: Oracle Database 11g RMAN Backup and Recovery (Oracle Press) - ON ITS WAY SOON! OCP: Oracle Database 11g Administrator Certified Professional Study Guide (Sybex) Oracle Database 11g New Features (Oracle Press) Oracle Database 10g New Features (Oracle Press) Other various titles Blog: http://robertgfreeman.blogspot.com Check out my new blog series on installing Oracle Database 11gR2 on Windows using VMWare! ________________________________ From: Cary Millsap <cary.millsap@xxxxxxxxxxxx> To: mwf@xxxxxxxx Cc: rgravens@xxxxxxxxx; gints.plivna@xxxxxxxxx; JSweetser@xxxxxxxx; oracle-l@xxxxxxxxxxxxx Sent: Mon, December 21, 2009 8:03:38 AM Subject: Re: quick FK question This isat the root of the Codd vs. Date debate summarized at http://www.dbdebunk.com/page/page/1706814.htm. I am eager to see Chris Date present on this near our office next month. Enrollment is still open, and there's plenty of space available (wink): http://method-r.com/education/107-cj-date-course Cary Millsap Method R Corporation On Mon, Dec 21, 2009 at 8:36 AM, Mark W. Farnham <mwf@xxxxxxxx> wrote: > >This is subject to testing and experimentation to see which way works better >>with the current technology. > >>It does raise and interesting question: When faced with incomplete data in >>columns that are not mere scalars but rather are either part of a key of the >>current relation or to another relation, is it better to include the tuple >>in your representation of the relation with some indication the tuple is >>incomplete or is it better to relegate the incomplete tuple to a staging >>location until its critical column values are known? > >>There is meaning added to the the database by having the constraint and a >>value that declares "this is a provisional value because we don't know the >>real value" as opposed to merely allowing the column to be null. When the >>provisional value can be used to drive a process to identify quality >>problems in the data without discarding the bits of the tuple that are known >>some good can come out of it. In terms of total work that must be done in an >>Oracle database to complete the data, this may be superior to having the >>incomplete tuples in a separate table. > >>But you mentioned "warehouse," which to a certain extent implies the data is >>in final form. Will the answers gotten from the warehouse be improved or >>degraded from including the incomplete tuple? Is there a good general answer >>to this question? (Am I mistaken or is this at root one of the bits Codd and >>Date had a mild disagreement about?) > >>Ah, the quasi-religious war that can be waged over this one! > >>So, does your "data warehouse modeler" produce models that work well to >>answer the questions put to it? Does this practice tend to make the models >>more or less usable? > >>Regards, > >>mwf > >-----Original Message----- >>From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] >On Behalf Of Rumpi Gravenstein >>Sent: Monday, December 21, 2009 8:01 AM >>To: gints.plivna@xxxxxxxxx >>Cc: JSweetser@xxxxxxxx; oracle-l@xxxxxxxxxxxxx >>Subject: Re: quick FK question > >><snip> >>I've seen once from some duhvelopers - they created all FK columns NOT >>NULL. Unfortunately of course there were cases with FK columns where >>actual value could not be provided. So what did they do? An obvious >>solution! ;) Added one row with id = -1 as a stub to all db tables. >></snip> > >>Gints I wanted to follow-up on this statement as our warehouse data >>modeler insists on doing this for all dimension joins claiming that >>this is good warehouse design as it avoids having to worry about outer >>joins. How would you respond? > >>-- >>Rumpi Gravenstein > >-- >//www.freelists.org/webpage/oracle-l > > > > >>-- >//www.freelists.org/webpage/oracle-l > > >