Re: RE: Any articles/books that take relational theory and make it

Well, Pascal has this to say about it:

http://www.dbdebunk.com/page/page/622521.htm

(This also links to some comments by Date on some articles by Ralph Kimball).

What it comes down to for me is this, the relational model provides a way (by being based on set theory and predicate logic) to ensure that your query results are mathematically sound, and thus you can trust your data. To paraphrase Pascal, a database is simply a set of axioms, which we can use (via queries) to form proofs about various aspects of our enterprise. If we ensure our data is normalized, and ensure that appropriate constraints are in place, we can trust that the axioms we store in the database are valid, and that our 'proofs' are also accurate, and ultiumately we can trust the information we are getting out of the database.

Again, I'd recommend Pascal's book, 'Practical issues...' as he explains these things more clearly than I can.

Granted our bosses/managers/clients, etc., may not be interested in hearing about normalization and predicate logic, but I think they do put value in having accurate data with which to pursure business interests. Being aware of the theoretical issues associated with the relational model can only help in our position as 'guardians of the data'.

Fwiw,

• Dan

On Thu, 20 Nov 2003 ryan_oracle_at_cox.net wrote:

> how does dimensional modelling used by datawarehousing fit into relational theory?
> >
> > From: Daniel Hanks <hanksdc_at_about-inc.com>
> > Date: 2003/11/19 Wed PM 04:35:03 EST
> > To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
> > Subject: RE: Any articles/books that take relational theory and make it
> >
> > Agreed. And I think you'll admit it's better to be familiar with and aware of the theory, even if current db products don't live up to the model 100%, so you know to bring up the kinds of issues you mention in the first place. In that sense, I think the knowledge to be gained from Date, Darwen, Pascal, etc., can be very practical.
> >
> > -- Dan
> >
> > On Wed, 19 Nov 2003, Niall Litchfield wrote:
> >
> > > I obviously can't speak for the list, but I find Fabian Pascal to be
> > > very interesting, but quite academic. What I *think* that I mean by this
> > > is that a lot of what he says seems to make theoretical sense, but I'm
> > > unsure how applicable it is to practice. IOW the general feel that I get
> > > from Fabian (and indeed Date) is that if something doesn't meet
> > > relational theory then it is flawed. This may well be a good default
> > > position to have, but I'm unprepared to say to folk who pay my wages
> > > 'sorry your data model isn't in 3NF' or 'you shall not use a
> > > materialized view'. I *will* quite happily say 'so how will you ensure
> > > data integrity?' 'what happens if another program uses the same data' or
> > > 'why did you use computed summaries?'
> > >
> > > Niall
> > > > -----Original Message-----
> > > > From: ml-errors_at_fatcity.com [mailto:ml-errors_at_fatcity.com] On
> > > > Behalf Of Daniel Hanks
> > > > Sent: 19 November 2003 16:25
> > > > To: Multiple recipients of list ORACLE-L
> > > > Subject: Re: Any articles/books that take relational theory
> > > > and make it
> > > >
> > > >
> > > > On Wed, 19 Nov 2003 ryan_oracle_at_cox.net wrote:
> > > >
> > > > > I swapped emails with a member of the list and Im having trouble
> > > > > seeing how you can take 3NF, BCNF, etc... and turn that into DBA
> > > > > speak. One of the guys told me that BCNF essentially means
> > > > you have a
> > > > > key that you can put a unique constraint on. Well that
> > > > makes this much
> > > > > easier to understand.
> > > > >
> > > >
> > > > Hrm, I thought a key, by definition, implied a unique constraint...
> > > >
> > > > > All my theory books just discuss theory. Anyone know some
> > > > that split
> > > > > the difference. IE, not Codd, not CJ Date, Not the academic
> > > > textbooks.
> > > > >
> > > >
> > > > I'm not sure what the opinion on Fabian Pascal is here on the
> > > > list, but I found his "Practical issues in Database
> > > > Management" to be very good. It's subtitled "A reference for
> > > > the thinking practitioner". It's not a textbook, but it does
> > > > make you use your brain a bit. It might be what you're
> > > > looking for. It has helped to clarify the relational model
> > > > for me, but might put some people off as it's critical
> > > > (without naming specific products) of most current
> > > > implementations of 'relational' databases.
> > > >
> > > > > Thanks.
> > > > >
> > > > >
> > > >
> > > > -- Dan
> > > > ==============================================================
> > > > ==========
> > > > Daniel Hanks - Systems/Database Administrator
> > > > About Inc., Web Services Division
> > > > ==============================================================
> > > > ==========
> > > > --
> > > > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > > > --
> > > > Author: Daniel Hanks
> > > > INET: hanksdc_at_about-inc.com
> > > >
> > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com
> > > > San Diego, California -- Mailing list and web hosting services
> > > > ---------------------------------------------------------------------
> > > > To REMOVE yourself from this mailing list, send an E-Mail message
> > > > to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru')
> > > > and in the message BODY, include a line containing: UNSUB
> > > > ORACLE-L (or the name of mailing list you want to be removed
> > > > from). You may also send the HELP command for other
> > > > information (like subscribing).
> > > >
> > >
> > >
> >
> > --
> > ========================================================================
> > Daniel Hanks - Systems/Database Administrator
> > About Inc., Web Services Division
> > ========================================================================
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.net
> > --
> > Author: Daniel Hanks
> > INET: hanksdc_at_about-inc.com
> >
> > Fat City Network Services -- 858-538-5051 http://www.fatcity.com
> > San Diego, California -- Mailing list and web hosting services
> > ---------------------------------------------------------------------
> > To REMOVE yourself from this mailing list, send an E-Mail message
> > to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> > the message BODY, include a line containing: UNSUB ORACLE-L
> > (or the name of mailing list you want to be removed from). You may
> > also send the HELP command for other information (like subscribing).
> >
>
>

-- 
========================================================================
   Daniel Hanks - Systems/Database Administrator
   About Inc., Web Services Division
========================================================================
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Daniel Hanks
  INET: hanksdc_at_about-inc.com

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).