[AccessD] Does anybody work on this level of abstraction with reallife apps data models?

Shamil,

You'll find more star schema information if you google data warehousing,
because it is commonly used in that world.  The OLAP thing is just an
elaboration on it. A good book is Ralph Kimball's book, The Date
Warehouse Toolkit.


Charlotte Foust

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Shamil
Salakhetdinov
Sent: Tuesday, March 28, 2006 12:50 PM
To: !DBA-MAIN
Subject: [AccessD] Does anybody work on this level of abstraction with
reallife apps data models?

Hi All,

I wanted to ask you how do you usually try to quickly understand
existing real life applications data models?

I mean the following:

- imagine you've got a task to program some utility code for an
application with rather tricky datamodel, working application and the
question to change this tricky datamodel is out of your responsibility -
you're not allowed even to discuss this question (I'm exaggerating about
that latter - just wanted to outline that your task is to understand the
existing datamodel whatever it's as quickly as possible, accept it and
to deliver your solution in time and as good as possible in the given
context because the customer is waiting for your working solution not
your considerations about datamodel and how good it could have been if
you have been allowed to change it....).

- there is a good description of this datamodel and its business area
but to program effectively you can use just a subset of this datamodel
and its description, which you need to quickly filter out from all the
existing
(thick) stuff to make a simple submodel diagram of the tables used in
your utilities and their relationships. And you do not want to spend
time to understand all the rest of this datamodel because you're more
interested to go watching the next series of Dexter and DeeDee or watch
the 100th time your favorite action movie like I do sometimes watch "The
White Sun of Desert" - a famous here Soviet action movie I first time
watched in 1969 :)...

The question is how to quickly understand such a data model and to get
it well arranged to solve the urgent customer task? (You given the
datamodel diagram but relationships are intersected in a tricky net)

Did you ever try to solve such a task first of all on an abstract level?
I mean did you ever try to "play" with existing datamodel relationships
diagram (graphical diagram I mean) without knowing(/without even taking
into
account) the meanings(titles) of the tables and  their relationships?
With the main purpose of this playing being to finally get a
relationships structure(graphical diagram) clearly showing you what are
the key points of this datamodel, what a the "juncture points", what are
the "bands and whistles"?

I did try and I think it always work for tricky, sometimes not optimal
but rather well normalized data model.

I think this is called "building star schema abstract method".
And it works in most of the cases.
Try it.

I did try to google for "start schema" concept definition and as far as
I see it is usually linked with OLAP not OLTP data models as here
(http://www.tdan.com/i021hy01.htm).
I did read first about star schema data models abstraction in a short
article in one of programming magazines somewhere in the summer 1995 and
since then I use this concept and it always work well am I building
datamodels from scratch or am I trying to understand/arrange existing
ones...

Just wanted to share how (sometimes boring task) of getting well
understanding of an intersected net of an existing data model
relationships can be converted in a joyful(?) game of shuffling these
table's relationships to get at a clear view of the subject business
area...

Shamil

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