ORM Overview

Terry Halpin's PhD Thesis on ORM - 1989

admin — Fri, 23 Nov 2007 17:24:24 GMT

This is Terry Halpin's early formalization of ORM. This is a bitmap copy of the original which is why it is an 18 MB pdf file that may take several minutes to download even on a fast connection. Terry found it impractical to make this available in text form, since he wrote the thesis in 1989 using WordStar and a tailor-made driver to print all the symbols on an old dot matrix printer.

Object-Role Modeling: an overview

admin — Fri, 23 Nov 2007 17:22:13 GMT

This white paper provides an overview of Object Role Modeling (ORM), using a case study to illustrate the main ideas. The steps used to design a conceptual schema for an information system are first explained in some detail. To help communicate the ideas, some mistakes are deliberately made. Checking procedures within the design method are later used to remove these errors. A simple example is included to show how the conceptual design may be "optimized" for relational database systems by applying a transformation. An algorithm for mapping this design to a normalized, relational database schema is then outlined. Finally, the paper gives a brief sketch of how ORM can be used as a sound basis for conceptual queries, object oriented modeling, and process/event modeling.

Object-Role Modeling - Springer Version

admin — Sun, 18 Nov 2007 19:33:37 GMT

This paper first appeared as chapter 4 of the following book: Bernus, P., Mertins, K. & Schmidt, G. (eds.) 1998, Handbook on Architectures of Information Systems, Springer. Details on this publication are available from Springer's website

Object Role Modeling (ORM) is a method for modeling and querying an information system at the conceptual level, and mapping between conceptual and logical (e.g. relational) levels. ORM comes in various flavors, including NIAM (Natural language Information Analysis Method). This article provides an overview of ORM, and notes its advantages over entity relationship and traditional object oriented modeling.

This paper and the Object Role Modeling Overview paper overlap substantially; however, the historical details, symbol summary, and references provide additional material.