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:
“I am black: I am the incarnation of a complete fusion with the world, an intuitive understanding of the earth, an abandonment of my ego in the heart of the cosmos, and no white man, no matter how intelligent he may be, can ever understand Louis Armstrong and the music of the Congo.”
—Frantz Fanon (1925–1961)
“Much poetry seems to be aware of its situation in time and of its relation to the metronome, the clock, and the calendar. ... The season or month is there to be felt; the day is there to be seized. Poems beginning “When” are much more numerous than those beginning “Where” of “If.” As the meter is running, the recurrent message tapped out by the passing of measured time is mortality.”
—William Harmon (b. 1938)