Re: The problem with denormalization.

One wonders if people do not know how to normalise data within the problem domain.

What I mean is that one should aim to normalise the data for use in the system being developed not for the real world.

Most business applications represent a subset of the real world. Some businesses that may even be thought of as the same type of business can use its data in different ways resulting in a couple of perfectly normalised databases that are not identical in structure.

Reporting can allow a different database design to the production database but still be normalised in its problem domain.

Usually people "denormalise" because they have attempted to normalise the real world for use in a business system.

Just a thought.

--
Slainte

Craig Alexander Morrison


"Laconic2" <laconic2_at_comcast.net> wrote in message
news:jKqdnbY-CITgnsXcRVn-ig_at_comcast.com...


> I recently ran into a place called the "Database design Blog".  In the


first


> article I scanned, I read the following:


>

> "Normalize until it hurts, denormalize until it works."

>

> There is some truth to this saying,  but it suffers from the same problem

as


> all the other advice about denormalization:  it doesn't tell you what to


do.


> It reminds me of the advice on how to get out of Witt's end:  "don't go


> west".

>

> Designers need better advice than "denormalize".  In my particular case,

> I've gotten a chance to design several "reporting databases"  over the

span


> of consulting for many clients.  Ever since I learned star schema, I've


used


> it wherever a reporting situation called for that type of database design.


>

> My point here is not how wonderful star schema is.  That's a different

> discussion.

>

> My point is that star schema provides a positive direction to the design

> process.  If you reach the point where you've decided to denormalize,  and

> you say, "now what do I do?",  you need more answers than "don't

normalize".


> "Don't normalize" is as vague as "don't go west."


>

>

> Before I learned star schema,  many of my denormalized databases were

> somewhat undisciplined.  Using star schema allowed me to follow an

organized


> system for design,  instead of merely not following the trail of


> normalization.

>

>

>

>