What is an EMdF schema?

An EMdF schema is the collection of:

  • enumerations and
  • object types

that make up the types in an EMdF database.

What is an EMdF schema script?

An EMdF schema script is an MQL script that creates an EMdF schema.

Is this a data model?

Yes, an EMdF schema defines the data model of a database. It is similar to the DTD or XML schema of an XML file, although the syntax and semantics are, of course, very different.

Is this a database model?

As I understand and use the terms, a database model is the nuts and bolts that make up the building blocks out of which you can create your data model. The data model is how you apply the database model to modeling an application domain.

So the EMdF model is the database model that supports your creating your own data model which suits your specific application domain.

For more information on what a database model is, I suggest you take a look at E.F. Codd's (1980) classic paper, "Data Models in Database Management" from the International Conference on Management of Data, Proceedings of the 1980 workshop on Data Abstraction, databases, and conceptual models, Pingree Park, Colorado, USA, pp. 112-114. It can be downloaded for free from the ACM Portal. Don't be confused by the fact that Codd calls it a "data model": The terms have been used and abused and have changed over the years.


  1. HOWTO
  2. Object types
  3. Features
  4. Enumerations
  5. Summary

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