Topic 3.3

Question 1

Who and when was the Relational Model proposed?

Answer 1

It was proposed by E. F. Codd in his seminal paper “A Relational Model of Data for Large Shared Data Banks” in 1970

Question 2

It is a table with columns and
rows.

Answer 2

Relation

Question 3

It is a named column of a
relation.

Answer 3

Attribute

Question 4

It is the set of allowable values
for one or more attributes.

Answer 4

Domain

Question 5

It is a row of a relation

Answer 5

Tuple

Question 6

It is the number of
attributes a relation contains.

Answer 6

Degree

Question 7

It is the number of tuples a relation contains.

Answer 7

Cardinality

Question 8

A collection of normalized
relations with distinct relation names.

Answer 8

Relational Database

Question 9

Two types of Database Relation:

Answer 9

• Relation Schema
• Relational Database Schema

Question 10

A named relation defined by a set of attribute and domain name pairs.

Answer 10

Relation Schema

Question 11

A set of relation schemas, each with a distinct name.

Answer 11

Relational Database Schema

Question 12

Types of Relational Keys(4):

Answer 12

1. Superkey
2. Candidate key
3. Primary key
4. Foreign key

Question 13

Types of Integrity Constraints(4):

Answer 13

1. Null
2. Entity Integrity
3. Referential Integrity
4. General Constraints

Question 14

A relation that does not
necessarily exist in its own right, but may be dynamically derived from one or more base relations.

Answer 14

View

Question 15

A named relation corresponding to an entity in the conceptual schema, whose tuples are physically stored in the database.

Answer 15

Base Relation