Quiz 5 (Final)

Question 1

Armstrongs Axioms

Answer 1

Rules or algebra of FDs incluing Reflexivity, Augmentation, Transitivity, Union, and Decomposition

Question 2

Boyce-Codd Normal Form

Answer 2

For every FD X -> A in F, A is an element of X; that is, it is a trivial FD, or X is a superkey

Question 3

Closure

Answer 3

Set of all FDs implied by a given set of FDs

Question 4

Decomposition

Answer 4

Breaking a relation into two or more separate relations

Question 5

Dependency Preserving Decomposition

Answer 5

Decomposition in which all dependencies are preserved

Question 6

Functional Dependency (FD)

Answer 6

A kind of integrity constraint - generalizes the idea of a key - an attribute or set of attributes determines another attribute(s)

Question 7

Integrity Constraint

Answer 7

Conditions that records in a relation must meet, restricts the data that can be stored in an instance of the database

Question 8

Lossless Join Decomposition

Answer 8

Decomposition in which no information is lost

Question 9

Third Normal Form

Answer 9

For every FD X -> A in F, A is an element of X; that is, it is a trivial FD, or X is a superkey, or A is part of some key for R

Question 10

Superkey

Answer 10

A set of columns that include a minimal key plus other non-key columns

Question 11

Reflexivity

Answer 11

If X is a superset of Y, then X -> (determines) Y

Question 12

Augmentation

Answer 12

If X -> (determines) Y, then XZ -> YZ for any Z

Question 13

Transitivity

Answer 13

If X -> (determines) Y and Y -> Z, then X -> Z

Question 14

Union

Answer 14

If X -> (determines) Y and X -> Z, then X -> YZ

Question 15

Decomposition

Answer 15

If X -> (determines) YZ, then X -> Y and X -> Z