Chapter 3 Lecture

Question 1

A database is in First Normal Form when the following two conditions are satisfied

Answer 1

Repeating groups have been resolved and the prime key has been identified

Question 2

A database is in Second Normal Form when Database is

Answer 2

in First Normal Form and every non-key attribute is fully functionally dependent on the primary key

Question 3

A database is in Third Normal Form when Database is

Answer 3

is in Second Normal Form and it has no transitive dependencies

Question 4

A foreign key must match a primary key value in another relation, or the foreign key value must be NULL. This rule is

Answer 4

Referential Integrity Rule

Question 5

The entity integrity rule states that:

Answer 5

no primary key attribute can be null

Question 6

What value will you assign to an attribute when you do not know it’s value or when the value is unknown

Answer 6

NULL

Question 7

An inconsistency may occur when attempting to update a table that is not normalized. What is the term given to such a situation?

Answer 7

Update Anomaly

Question 8

Is it possible for PART of a foreign key to be NULL? Why?

Answer 8

No. Either the whole foreign key is NULL or the whole foreign key is NOT NULL

Question 9

T/F - Normalization is done after Logical Database Design is complete

Answer 9

True

Question 10

T/F - Normalization takes into consideration how data is displayed, how it is used in reports and how a database is queried.

Answer 10

False

Question 11

T/F - One of the two conditions for a relation to be in First Normal Form is: absence of repeating groups.

Answer 11

True

Question 12

T/F - When inserting a row in a normalized database, i.e., 3NF, there may be additional insertions that result in duplication of data.

Answer 12

False - “You cannot add any data you cannot remove any data; you just focus on removing the anomalies”

Question 13

T/F - When deleting a row in a normalized database, i.e., 3NF, there may be loss of data.

Answer 13

False

Question 14

T/F - When modifying a single row in a normalized database, there may be changes required to other rows.

Answer 14

False - That is the objective of a normalized database

Question 15

T/F - The process of Normalization is reversible, i.e., it is possible to put data in 1NF from 3NF.

Answer 15

True

Question 16

T/F - In the Normalization process, it is possible that some columns can be ignored.

Answer 16

False

Question 17

T/F - A NULL value is the same as a space or a zero

Answer 17

False

Question 18

T/F - The entity integrity rule states that a primary key attribute can be null

Answer 18

False

Question 19

T/F - Referential integrity is satisfied when a value of one column of a table exists as a value of another column in a different, or same, table.

Answer 19

True

Question 20

T/F - A foreign key can have a NULL value.

Answer 20

True

Question 21

T/F - The columns of a relation can be rearranged without changing the meaning or use of the relation.

Answer 21

True

Question 22

T/F - Rows of a relation must not be interchanged and must be stored in a certain sequence

Answer 22

False

Question 23

T/F - A primary key uniquely identifies each row in a relation

Answer 23

True

Question 24

T/F - A composite key consists of only one attribute

Answer 24

False

Question 25

The objective of Normalization is to:

Answer 25

-Relations are free of anomalies -Easier to maintain referential integrity -Easier to maintain data

Question 26

When you normalize a database, will it run faster or slower?

Answer 26

Slower. Everything in one big table will likely run faster. (Nowadays computers are so fast it doesn't really matter)

Question 27

Software that is used to create, maintain, and provide controlled access to databases is called

Answer 27

Database Management System (DBMS)

Question 28

What are 3 main purposes of a database management system (DMBS)

Answer 28

Store data, Create Data, Update Data

Question 29

T/F - A relationship is an association between entity types

Answer 29

True

Question 30

The _______ of a relationship is the number of entity types that participate in the relationship

Answer 30

Degree

Question 31

A rule that specifies the number of instances of one or more entities

Answer 31

Cardinality

Question 32

Processed data is called _________

Answer 32

Information

Question 33

Data in a table is stored in the form of _________ and ____________

Answer 33

Rows, Columns

Question 34

Description of properties of data is called _________________

Answer 34

Metadata

Question 35

A word or phrase that has a specific meaning for the business

Answer 35

Term

Question 36

A fact is an association between two or more

Answer 36

Terms

Question 37

Supplier, Student, Book, Course are examples of

Answer 37

Entities

Question 38

A strong entity is an entity that exists independent of other entity types

Answer 38

True

Question 39

When it comes to storing and sharing, a business rule must be

Answer 39

Stored only once in a central repository then shared throughout the organization

Question 40

T/F - A business rule can have many interpretations. Each stakeholder can have his own interpretation.

Answer 40

False

Question 41

Data models in an organization change less frequently than business rules.

Answer 41

True

Question 42

An entity whose existence depends on another entity is called

Answer 42

A weak entity

Question 43

An attribute that must have a value for every entity (relation) instance that it is associated with is a/an

Answer 43

Required attribute (in SQL it's called mandatory or NOT NULL)

Question 44

An attribute that cannot be broken into smaller components is called a/an

Answer 44

Atomic attribute

Question 45

An attribute whose value can be calculated from other attributes is called a

Answer 45

derived attribute

Question 46

A Relational Database represents data as a collection of

Answer 46

Tables

Question 47

A time value that is associated with a data value, indicating when the data value was updated

Answer 47

Timestamp

Question 48

When it comes to data, the term update implies

Answer 48

Insertion, deletion or change or a data value

Question 49

Consider an invoice. Line_Item_Amount is an attribute that is the product of Quantity and Unit_Price, Line_Total is the sum of all Line_Item_Amount in an invoice. The data analyst decides not to store Line_Item_Amount and Line_Total. How will you describe this attribute?

Answer 49

Derived Attribute

Question 50

What is partial functional dependecy?

Answer 50

When a non-key depends on only part of the prime key

Question 51

What is transitive dependency?

Answer 51

When a non-key depends on another non-key