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
Famous quotes containing the words armstrong and/or relation:
“But Jonnë had a bright sword by his side,
And it was made of the mettle so free,
That had not the king stept his foot aside,
He had smitten his head from his faire bodde.”
—Unknown. Johnie Armstrong (l. 45–48)
“There is a constant in the average American imagination and taste, for which the past must be preserved and celebrated in full-scale authentic copy; a philosophy of immortality as duplication. It dominates the relation with the self, with the past, not infrequently with the present, always with History and, even, with the European tradition.”
—Umberto Eco (b. 1932)