Principle of Orthogonal Design
Encyclopedia
The Principle of Orthogonal Design (abbreviated POOD) was developed by database researchers David McGoveran
and Christopher J. Date
in the early 1990s, and first published "A New Database Design Principle" in the July 1994 issue of Database Programming and Design and reprinted several times. It is the second of the two principles of database design
, which seek to prevent databases from being too complicated or redundant, the first principle being the Principle of Full Normalization (POFN).
Simply put, it says that no two relations in a relational database
should be defined in such a way that they can represent the same facts. As with database normalization
, POOD serves to eliminate uncontrolled storage redundancy and expressive ambiguity, especially useful for applying updates to virtual relations (e.g., view (database)
). Although simple in concept, POOD is frequently misunderstood and the formal expression of POOD continues to be refined.
David McGoveran
David McGoveran is a consultant, researcher, lecturer, and industry analyst to the software industry; author of numerous books and articles in the fields of relational databases, transaction processing, business intelligence, business process management, mathematics, and physics; and an inventor...
and Christopher J. Date
Christopher J. Date
Chris Date is an independent author, lecturer, researcher, and consultant, specializing in relational database theory.-Biography:Chris Date attended High Wycombe Royal Grammar School from 1951 to 1958 and received his BA in Mathematics from Cambridge University in 1962. He entered the computer...
in the early 1990s, and first published "A New Database Design Principle" in the July 1994 issue of Database Programming and Design and reprinted several times. It is the second of the two principles of database design
Database design
Database design is the process of producing a detailed data model of a database. This logical data model contains all the needed logical and physical design choices and physical storage parameters needed to generate a design in a Data Definition Language, which can then be used to create a database...
, which seek to prevent databases from being too complicated or redundant, the first principle being the Principle of Full Normalization (POFN).
Simply put, it says that no two relations in a relational database
Relational database
A relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
should be defined in such a way that they can represent the same facts. As with database normalization
Database normalization
In the design of a relational database management system , the process of organizing data to minimize redundancy is called normalization. The goal of database normalization is to decompose relations with anomalies in order to produce smaller, well-structured relations...
, POOD serves to eliminate uncontrolled storage redundancy and expressive ambiguity, especially useful for applying updates to virtual relations (e.g., view (database)
View (database)
In database theory, a view consists of a stored query accessible as a virtual table in a relational database or a set of documents in a document-oriented database composed of the result set of a query or map and reduce functions...
). Although simple in concept, POOD is frequently misunderstood and the formal expression of POOD continues to be refined.
Sources
- Database Debunkings: The Principle of Orthogonal Design, Part I, by D. McGoveran and C. J. Date http://www.dbdebunk.com/page/page/622331.htm
- Database Debunkings: The Principle of Orthogonal Design, Part II, by D. McGoveran and C. J. Date http://www.dbdebunk.com/page/page/622312.htm
- David McGoveran (personal interview) http://www.alternativetech.com