Re: Conceptual Data Model (Federal Enterprise Architecture)
- From: Gints Plivna <gints.plivna@xxxxxxxxx>
- To: oracledbaquestions@xxxxxxxxx
- Date: Tue, 23 Jul 2013 23:32:45 +0300
Quite a while ago I wrote an article containing some info about that
http://www.gplivna.eu/papers/data_waste_or_data_base.htm
It contains also some literature as well as links. It seems most of them
works also today especially in section 3. Lack of initial design
Generally I'd say you just:
- write entities in terms of good old ER model (but they could be very
general, for example, just address without any detailed attributes, or
address could be just an attribute, most of the time it depends on what
kind of business you do). Another classic example - customers and orders
are probably valid subjects of conceptual data model, but probably order
items, order statuses, and other detailed info about order processing
usually is not detailed in initial conceptual data model.
- write relationships
- entities may contain business objects that may or may not be in your
future database, i.e., probably you don't even make tables for all
entities. There may be different reasons - lack of money, not reasonable to
automate process at all, there are existing products out of the box etc etc)
- don't think about DBMS (Oracle, SQL Server, whatever). If you have
attributes (I'd say at least there should be main attributes explaining
each concept, but that probably is just my understanding :), don't think
whether they are varchar, number, date, clob whatever. You (or somebody
other) will think later about that. Probably later you'll find that
attribute address should be stored in separate entity (table) containing 17
columns, but for just a sake of concept it is not important.
- think and write in terms understandable for business people.
- start thinking from top to bottom, i.e. just write down some, more, maybe
all big business concepts and then find what are the most critical and try
further detailing them. If you have limited amount of time, just limit for
each part of the initial model let's say an hour. If you have more time, go
on.
- there isn't one and only one right and precise definition of conceptual
data model as well as there isn't one and only one best conceptual data
model for each business.
HTH
Gints Plivna
2013/7/23 Dba DBA <oracledbaquestions@xxxxxxxxx>
> This is different from the standard logical/physical models that DBAs
> normally do. From what I can tell its a very high level picture of our data
> that maps it to business functions for upper management types who need to
> look at many different applications/DBs and make sure that the projects
> align to the business.
> I have never made one of these before. I was basically given a week to do
> it, then a review with the client. The doc I got from them looks like its
> partially a copy and paste of boilerplate text from an 'do you want to be
> an Enterprise Architect?' blog. The rest is vagueries about naming
> conventions.
>
> No pictures. (all those sections say 'to be completed'). All my google
> searches seem to turn up are vague references. Many of which are copy and
> pastes of the link below.
>
>
>
> http://blog.infoadvisors.com/index.php/articles/what-are-conceptual-logical-and-physical-data-models/
>
> Is there a data modeller listserv? Paul Dorsey and several other guys who
> focus more on the modelling end used to hang out on the odtug listservs,
> but they shut down. Ill take a book recommendation, but it needs to be
> something at the store. If I order it, it will arrive too late.
>
>
> --
> //www.freelists.org/webpage/oracle-l
>
>
>
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