To Schema or Not to Schema...

[jfrost10]

Hey guys,

I've been reading a book on UML for DataBase design, and wanted to get your input on the subject of data base Schema.

I'm no DBA, but so far my understanding is that the database schema is based on some ERD diagram, mapping out the database. However, since you can model table relationships within the UML, is there any real need for a schema? Does it hold any worth other than just holding a picture of how the database looks, and the relationships between the entities?

It just seems redundant to me, since we model all of that within the UML diagrams already.

Thanks for your input,

Jack

 

[wgcs]

I believe that what you are describing that you already do in your UML diagrams is exactly what the book is talking about doing.

You could say "every database has a definite Schema whether it is documented or not" just like "every person has a definite height whether it is measured or not".

You're documenting your schema in the same UML document that you're documenting other things.

The book is probably describing an "orthodox" method of using UML for describing Schemas.

However, a Schema can be documented many ways: XML uses XML itself to define a Schema, not UML, but you could just as easily use UML.