Tom Kelliher, CS 318
Mar. 8, 2002
Return homework Monday. Midterm review Monday. Midterm will cover Chapters 1--7.
Introduction to functional dependencies.
Using Armstrong's Axioms:
Therefore, an algorithm exists to do entailment checking.
By the union property then, .
Correctness. Use induction. (Not the entire proof.)
old := closure
if there is an FD such that then
until old = closure
Observe . Why?
By decomposition, .
Suppose we have where . Justify each of the following steps.
Suppose we have , where and contains