What are best practices for data models?

[Ken Sturgeon]

At the risk of frustrating some I'm going to ask some very fundamental
questions regarding the use of Visio as a data modeler. While I'm no
stranger to data models or relational databases I am new when it comes to
using Visio as the modeler.

I have a database with approximately 275 tables. As I reverse engineer I'm
asked if I want to allow Visio to add the shapes to the current page.
Clearly a single page with 275 tables gets pretty busy. Should I allow Visio
to create this monolithic page or, knowing that I will ultimately drag &
drop logical groupings (subject areas) of tables on various pages prevent
Visio from reverse engineering the entire model on one page?

If I do allow Visio to create this single page model, am I then restricted
to making all of the database changes to this page expecting that they'll
automatically manifest in the other pages that I've created, or will I be
free to make the changes to a table on any page in which it's visible? I
guess I'm simply wondering what most users do. Do you maintain one page that
shows all of the database shapes? Do you create smaller pages of logical
groupings of tables? Do you do both?

I recognize that foreign keys will often relate one subject area with
another and the only way I'll physically see the foreign key relationship is
to show some of the tables multiple times on different pages. How does that
affect the underlying model?

I guess in summary, I'm really just looking for some guidance as to how I
can best manage the model. Are there any good online tutorials?

Thanks very much for your help and your patience with yet another newbie.

--- Ken Sturgeon

 

[chrisb]

You can reverse engineer the database to one page, then remove (rather
than delete, ie - "keep in the underlying model") the tables from that
page - you can then get rid of that page, but the tables and their
relationships are still stored in the visio document.

Create new pages and drag the relevant tables onto those pages (from
the Tables pane).

My article at CodeProject.com explains how to do this:
http://www.codeproject.com/gen/design/visioDatabase.asp

See the section "Using Pages to organise the tables."

Regards

Chris.

 

[Ken Sturgeon]

Thanks for your insight Chris... good article.

Ken