Lesson 3

Question 1

Edgar Frank Ted Codd was the pioneer of the ____________ for database management in 1970.

Answer 1

relational model

Question 2

The relational model is based on

Answer 2

predicate logic and set theory.

Question 3

Is used extensively in mathematics to provide a framework in which an assertion (statement of fact) can be verified as either true or false.

Answer 3

Predicate Logic

Question 4

is a part of mathematical science that deals with sets, or groups of things, and is used as the basis for data manipulation in the relational model.

Answer 4

Set Theory

Question 5

The relational model has three (3) components:
A logical data structure represented by _____________.
A set of ___________ rules to enforce that the data is _________ and remains __________ over time.
A set of ____________ that defines how data is manipulated.

Answer 5

The relational model has three (3) components:
A logical data structure represented by relations.
A set of integrity rules to enforce that the data is consistent and remains consistent over time.
A set of operations that defines how data is manipulated.

Question 6

is a two-dimensional structure composed of rows and columns.

Answer 6

A table (relation)

Question 7

Each table row (tuple) represents

Answer 7

data about an entity.

Question 8

Each table column represents an _________, and each column has a distinct _______.

Answer 8

Each table column represents an attribute, and each column has a distinct name.

Question 9

Each intersection of a row and column represents

Answer 9

a single data value.

Question 10

All values in a column must conform to the same data ______

Answer 10

format

Question 11

Each column has a specific range of values known as the ____________

Answer 11

attribute domain

Question 12

The order of the rows and columns is ___________ in a DBMS.

Answer 12

not important

Question 13

is an attribute or group of attributes that determines the values of other attributes.

Answer 13

key

Question 14

is the state in which knowing the value of an attribute makes it possible to determine the value of another. It is based on the relationships among the attributes.

Answer 14

Determination

Question 15

means that the value of one or more attributes determines the value of one or more other attributes.

Answer 15

Functional dependence

Question 16

The attribute whose value determines another is called

Answer 16

determinant or the key.

Question 17

Functional dependence can involve a ____________that comprises multiple ____________.

Answer 17

Functional dependence can involve a determinant that comprises multiple attributes.

Question 18

An attribute or combination that uniquely identifies any row in the table.

Answer 18

Super Key

Question 19

A superkey without any unnecessary attributes.

Answer 19

Candidate Key

Question 20

A candidate key selected to uniquely identify all other attributes values in any given row; cannot contain null entries.

Answer 20

Primary Key

Question 21

An attribute or combination of attributes in one table whose values must either match the primary key in another table or be null.

Answer 21

Foreign Key

Question 22

An attribute or combination of attributes used strictly for data retrieval purposes.

Answer 22

Secondary Key

Question 23

An ____________is the condition in which each row is a table has its own unique identity.

Answer 23

entity integrity

Question 24

is the conditional in which every reference to an entity instance by another entity instance is valid.

Answer 24

referential integrity

Question 25

Entity Integrity Requirement: All primary key entries are __________ , and no part of a primary key may be __________.

Answer 25

Entity Integrity Requirement: All primary key entries are unique, and no part of a primary key may be null.

Question 26

Entity Integrity Purpose: Each row will have a ___________ identity, and foreign key values can properly reference ____________ key values.

Answer 26

Purpose: Each row will have a unique identity, and foreign key values can properly reference primary key values.

Question 27

Referential Integrity Requirement: A foreign key may have either a ________ entry, as long as it is not a part of its table’s __________ key, or an entry that matches the __________ key value in a table to which it is related. Every non-full ________ key value must reference an existing ________ key value.

Answer 27

equirement: A foreign key may have either a null entry, as long as it is not a part of its table’s primary key, or an entry that matches the primary key value in a table to which it is related. Every non-full foreign key value must reference an existing primary key value.

Question 28

Referential Integrity Purpose: It is possible for an attribute not to have a ___________, but it will be impossible to have an _________- entry. The enforcement of the referential integrity rule makes it possible to __________ a row in one table whose primary key has mandatory matching __________ key values in another table.

Answer 28

Purpose: It is possible for an attribute not to have a corresponding value, but it will be impossible to have an invalid entry. The enforcement of the referential integrity rule makes it possible to delete a row in one table whose primary key has mandatory matching foreign key values in another table.

Question 29

is a set of mathematical principles that form the basis for manipulating relational table contents.

Answer 29

Relational algebra

Question 30

The use of relational algebra operators on existing relations (tables) produces new relations is called

Answer 30

closure

Question 31

The condition to be evaluated is also known as

Answer 31

predicate