Relational Model

Question 1

Set

Answer 1

unordered collection of distinct objects

Question 2

Domain

Answer 2

set of values of some type

e.g. list of zipcodes

Question 3

attribute

Answer 3

name of the domain

e.g. “zipcodes”

Question 4

Relations

Answer 4

subset of cartesian product

Question 5

Atomicity

Answer 5

single valued

means ease of querying

Question 6

Table metaphor, relation is ? tuple is a ? attribute is a ?

Answer 6

relation is a table, tuple is a row, column is an attribute

Question 7

Superkey

Answer 7

set of attributes K of R such that no two tuples in any valid relation instance will have the same value for K

Question 8

Candidate key

Answer 8

minimal superkey; a superkey K such that removal of any attribute from K results in a set of attributes that is not a superkey