Armstrong’s Axiom

What Does Armstrong’s Axiom Mean?

Armstrong’s Axiom is a mathematical notation used to find the functional dependencies in a database. Conceived by William W. Armstrong, it is a list of axioms or inference rules that can be implemented on any relational database. It is denoted by the symbol F+.

Techopedia Explains Armstrong’s Axiom

Armstrong’s Axiom is used to analyze, refine and maintain relational databases. It has three major modes or inferences applied on a set of data. They are as follows:

Axiom of Reflexivity: If user name (A) and title (B) represent a person’s name, then the relationship between both (A and B) is of little importance.
Axiom of Augmentation: If a user ID defines a person’s name, then the user ID with email quota define the person’s name and email quota.
Axiom of Transitivity: If a user ID determines a person’s name, and a person’s name defines the department, then the department can define the user ID.

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Margaret Rouse

Technology expert

Margaret is an award-winning writer and educator known for her ability to explain complex technical topics to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles in the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret’s idea of a fun day is to help IT and business professionals to learn to speak each other’s highly specialized languages.

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