Tag: erd

Subtypes or Roles for parties

Recently I participated in a discussion of a common problem in data modelling. The question is whether to represent parties (groups) as roles or as subtypes (generalisation hierarchy).

When designing the Conceptual Data Model, parties can be represented as subtypes provided there is a common context amongst sub-types. In the Logical Model, subtypes should be represented only if each subtype has a unique concept that the others don’t.

You can read view the LinkedIn discussion here and/or see my Short notes on Barker’s ERD Notation.

ERD Modelling using Barker’s Notation

ERD Modelling using Barker’s Notation

A key process in database development is obviously database modelling and the main diagrams used are ERD. A number of notations exist, some particular to evangelised by particular DBMS. Here I am documenting a short course/notes about ERD modelling using the Barker’s notation, which is greatly adopted by Oracle.

As usual here is the link, do feel free to comment!

Short notes on Barker’s ERD Notation

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