[thelist] Database Design Question

Joshua Olson joshua at waetech.com
Wed Mar 2 13:02:23 CST 2005

> -----Original Message-----
> From: Luther, Ron
> Sent: Wednesday, March 02, 2005 12:19 PM
> >>As a rule of thumb, do not represent the same data twice in a single
> >>database.  Keeping detailed records plus summary records would be a
> >>violation of this rule of thumb.
> ... for OLTP systems naturally.  In an OLAP setting 'denormalization'
> is quite desirable.

For the sake of thelist, I'd like to point out that the rule of thumb only
applies within a single database.  Moving the information into another
database, massaging it into an OLAP ready version, and utilizing it as such,
would not be a violation of the rule of thumb.  

> [Hey Joshua,
> I'm pretty sure you have a good idea how _many_ projects (particularly
> of the sort run into by a fairly large percentage of our members here)
> waffle back and forth ...
> * Client wants a shopping cart system.
> * Then client wants reporting; inventory, backlog, product line stats,
> etc.
> * Then client wants cart modified to accumulate more data.

Absolutely!  None of those requirements would necessitate denormalization,

> Those kinds of situations can make it pretty easy, for a lot of folks
> to forget the sharp difference between OLTP and OLAP and try building
> 'blended' solutions.
> I AGREE! ... it's a 'bad idea' (TM).

Might want to (r) and (c) that phrase, too.  :-)  So long as information is
not represented in multiple ways, there's no real reason why a database
designed for OLTP could not have attributes (indexes, views, etc) to
facilitate OLAP.  However, you are about to mention...

> {And I'm also familiar with (and agree with) the stories of 
> the DBAs who
> were fired for indexing the OLTP systems to speed up reporting.)  ;-)

Never heard that, but way cool, nonetheless.  A violation of corporate
policy, no matter how nit-picky it may be, is just that.  Even a DBA needs
to appreciate the nuances of corporate politics.

> Any interest in writing or collaborating on an evolt article on tips
> to help folks in the trenches keep this straight?

Perhaps a bit, yes.  There are probably many people on this list who would
be ideal persons to tackle an article such as this.  My relationship with
OLAP vs. OLTP is skewed heavily towards OLTP because of my heavy OOP
background .  A person with a balanced exposure would be invaluable in
writing such an article.  Where's Rudy when ya need 'im?

Joshua Olson
Web Application Engineer
WAE Tech Inc.

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