From class diagram to physical data model : conceptual data model or not ?

#1

Hello,

Our developers use UML and make class diagrams (A).

Our DBA team wants to make physical diagrams with powerdesigner (B).

Quote:

From (A) to (B) we can :

- create a data model diagram (ER) and derive it in its physical form

- or directly create the physical diagram provided the class diagram
is complete

After all, what is the point of making an ER conceptual diagram when
the class diagram so much resembles it.
(entity <=> class, ...)

What would be your advice ?

This is certainly a naive question ... don't be too harsh =)

Thanks in advance

Jean-Michel

#2

On 29 mai, 17:53, zejea... (AT) gmail (DOT) com wrote:

Quote:

Hello,

Our developers use UML and make class diagrams (A).

Our DBA team wants to make physical diagrams with powerdesigner (B).

From (A) to (B) we can :

- create a data model diagram (ER) and derive it in its physical form

- or directly create the physical diagram provided the class diagram
is complete

After all, what is the point of making an ER conceptual diagram when
the class diagram so much resembles it.
(entity <=> class, ...)

What would be your advice ?

This is certainly a naive question ... don't be too harsh =)

Thanks in advance

Jean-Michel

If you can't make the difference now try to bring your team to show
you the difference on the complete life cycle...

Ask both your DBA's and developpers the following questions:

Quote:

How do you plan on impementing business logic (choose examples)
How do you plan on maintaining the system over a 2 years period
Could give me a ROI 2 years plan for the system you are planning to design
How will maintain data integrity
Whart is exactly to to you *performance* (tip: if one just answers *response time* just kill the answer)

The most convincing answer should demonstate who has bee giving more
thought about this...

Hope this helps...

#3

On May 29, 11:53 am, zejea... (AT) gmail (DOT) com wrote:

Quote:

Hello,

Our developers use UML and make class diagrams (A).

Our DBA team wants to make physical diagrams with powerdesigner (B).

From (A) to (B) we can :

- create a data model diagram (ER) and derive it in its physical form

- or directly create the physical diagram provided the class diagram
is complete

After all, what is the point of making an ER conceptual diagram when
the class diagram so much resembles it.
(entity <=> class, ...)

What would be your advice ?

This is certainly a naive question ... don't be too harsh =)

Thanks in advance

Jean-Michel

ER diagrams are DBMS independent, whereas class diagrams are DBMS
dependent. ER model gives you high level picture of your design and
changes are easily acceptable.

#4

Hi,

On 29 mayo, 17:53, zejea... (AT) gmail (DOT) com wrote:

Quote:

After all, what is the point of making an ER conceptual diagram when
the class diagram so much resembles it.
(entity <=> class, ...)

What is the point of making an UML class diagram when it is
essentially the same as an ER diagram?

Quote:

What would be your advice ?

Draw less and work more.

Regards

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From class diagram to physical data model : conceptual data model or not ?

comp.databases comp.databases

From class diagram to physical data model : conceptual data model or not ? - 05-29-2007 , 11:53 AM

Re: From class diagram to physical data model : conceptual data model or not ? - 05-31-2007 , 03:54 PM

Re: From class diagram to physical data model : conceptual data model or not ? - 06-01-2007 , 10:06 AM

Re: From class diagram to physical data model : conceptual data model or not ? - 06-01-2007 , 02:14 PM