Re: By The Dawn's Normal Light
Date: Tue, 26 Oct 2004 08:09:57 -0400
Message-ID: <BKadnaWd-IQ_o-PcRVn-uQ_at_comcast.com>
"Ja Lar" <jalar_at_nomail.com> wrote in message
news:clksrl$5ps$1_at_news.net.uni-c.dk...
> As you see, while elaborating my view, I come to the conclusion that I in
> fact agree that tables can be talked about on a logical (eg
"normalisation")
> level. Thank you for lifting me!
In connection with all this discussion of "logical table" vs "physical
table", I'm going to point out that
Data Architect (DA) did something that I considered a little unusual: they
objects that were called Conceptual Data Models (CDM) and objects called
Physical Data Models (PDM), but no logical data models in between.
If you converted from a CDM to a PDM, it went directly from ER style modeling to what I'll call SQL style modeling, with tables and indexes and other objects.
The objects inside a PDM were classed into two kinds: Schema Objects and Database Objects. An example of a database object would be an (Oracle) TABLESPACE. Examples of Database Objects would be tables or stored procedures.
It's the absence of an intermediate model that struck me as unusual, because I was used to doing the same thing manually in three steps, Conceptual, Logical, and Physical. But they must have had their reasons. I never found any deficiency in DA that was due to the absence of a logical data model.
I'm wondering what you have to say about this.
BTW, A while ago, I told Marshall that I was about to Paul's objection to my definition, when in fact, I was about to agree with yours. Sorry about not crediting you, and thanks for the correction. Received on Tue Oct 26 2004 - 14:09:57 CEST