Given a set of functional dependencies, the Armstrong relation is a relation which satisfies all the functional dependencies in the closure and only those dependencies. Unfortunately, the minimum-size Armstrong relation for a given set of dependencies can have a size which is an exponential function of the number of attributes in the dependencies considered.
Read more about this topic: Armstrong's Axioms
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“rather then men shall say we were hange’d,
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—Unknown. Johnie Armstrong (l. 51–52)
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—René Descartes (1596–1650)