Flash Cards

Question 1

A process of transforming conceptual data model into logical data model such as relational data model

Answer 1

Logical Database Design.

Question 2

Most commonly used in modern Database applications

Answer 2

Relational Data model ( or relational model)

Question 3

Data are organized in the form of table with rows and columns

Answer 3

Data structure

Question 4

Operation are made using SQL to manipulate data stored in the relations

Answer 4

Data manipulation

Question 5

Facilities are included to specify business rules that maintain the integrity of data when they are manipulated.

Answer 5

Data integrity

Question 6

A named, two dimensional table of data.

Answer 6

Relation

Question 7

Consists of a set of named columns and an arbitrary number of unnamed rows.

Answer 7

Relation (or table)

Question 8

Becomes a relation name

Answer 8

Entity type

Question 9

Named column of a relation.

Answer 9

Attribute

Question 10

Each ___ of a relation corresponds to a record that contains ____ values for a single ____.

Answer 10

Row(Tuple), data(attribute), entity(instance)

Question 11

An attribute or combination of attributes that uniquely identifies each row in a relation
EMPLOYEE1(*Emp_ID,Name,Dept_Name,Salary)

Answer 11

Primary Key

Question 12

A primary key that consists of more than one attribute

Answer 12

Composite Key

Question 13

An attribute in a relation of a database that serves as the primary key of another relation in the same database
E.g. DEPARTMENT(Dept_name, Location,Tel_no)
EMPLOYEE1(Emp_ID, Name, ^Dept_Name,Salary)

Answer 13

Foreign Key

Question 14

Not all tables are relations

Answer 14

True

Question 15

each relation has a unique name

Answer 15

true

Question 16

The value at the intersection of each row and column is atomic. No multivalued attributes are allowed.

Answer 16

True

Question 17

Each row is unique. No two identical rows in a relation.

Answer 17

True

Question 18

Each attribute or column within a table has a unique name.

Answer 18

True

Question 19

The sequence of columns is insignificant

Answer 19

True

Question 20

The sequence of rows is insignificant

Answer 20

True

Question 21

Consists of any number of relations

Answer 21

Relational Database

Question 22

a description of the overall logical structure of the database

Answer 22

Schema

Question 23

Two common methods for expressing a schema

Answer 23

Short text statements, a graphical representation

Question 24

Includes several types of constraints to maintain the accuracy and integrity of data in the database

Answer 24

Relational Data Model

Question 25

Domain Constraints, Entity Integrity, Referential Integrity

Answer 25

Major Integrity Constraints

Question 26

All the values that appear in a column of a relation must be taken from the same domain

Answer 26

Domain Constraints

Question 27

The set of values that may be assigned to an attribute

Answer 27

Domain

Question 28

Domain name, meaning, data type, size or length, allowable values or allowable range

Answer 28

Domain definition

Question 29

No Primary Key attribute (or component of a primary key attribute) can be null. It guarantees that every primary key attribute non- null.

Answer 29

Entity Integrity

Question 30

assures that every relation has a primary key and that the data values for that primary key are all valid

Answer 30

Entity integrity rule

Question 31

A value that may be assigned to an attributes when no other value applies or when the applicable value is unknown

Answer 31

Null

Question 32

A rule that states that either each foreign key value must match a primary key value in another relation or the foreign key value must be null

Answer 32

Referential Integrity

Question 33

In relational data models, associations between tables are defined through the use of ____

Answer 33

foreign keys

Question 34

If the relationship is optional, then the foreign key could be null

Answer 34

True

Question 35

Whether a foreign key can be null must be specified as a property of the foreign key attribute when the database is defined

Answer 35

True

Question 36

A foreign key name must be the same as primary key name.

Answer 36

False - a foreign key name could be different from primary key name.

Question 37

The foreign and primary keys can be from different domains.

Answer 37

False - The foreign and primary keys must be from the same domain.

Question 38

A relation that contains minimal redundancy and allows users to insert, modify, and delete the rows in a table without anomalies

Answer 38

Well-structured Relation

Question 39

An error or inconsistency that may result when a user attempts to update a table that contains redundant data.

Answer 39

Anomaly

Question 40

Three types of anomalies

Answer 40

Insertion, deletion, modification anomaly