IT131-10 Quiz 3

Match the following: 1. 1NF 2. 2NF 3. 3NF 4. 4NF 5. 5NF

1. 1NF - Non PK depend on PK (Fully Functionally Dependent) 2. 2NF - All columns can only be determined by PK (no transitively dependent attributes) 3. 3NF - All columns can only be determined by PK (no transitively dependent attributes) 4. 4NF - No multi value dependency 5. 5NF - involves an anomaly where a table can be split part but not correctly joined back together

Match the following 1. Question 2. Disjoint Subtype 3. Overlapping Subtype 4. Partial Completeness 5. Total Completeness

1. Question - contain a unique subset of the supertype entity set 2. Disjoint Subtype - each entity instance of the supertype can appear in only one of the subtypes 3. Overlapping Subtype - contain non-unique subsets of the supertype entity set, each entity instance of the supertype may appear in more than one subtype 4. Partial Completeness - not every instance of supertype is a member of a subtype. Subtype discriminator can be null. 5. Total Completeness - every instance of supertype is a member of atleast 1 subtype. Subtype discriminator cannot be null.

Which normal form is considered adequate for relational database design ?

1NF

__________ and __________ are the weakest and strongest normal forms respectively.

1NF and BCNF

(NEEDS picture)

?

(NEEDS picture) Choose the correct answer from the following choices ?

?

(NEEDS picture) The above relation shows ?

?

(NEEDS picture) The above relation violates the condition of ____ ?

?

(NEEDS picture) The above relation violates the condition of which normal form ?

?

(NEEDS picture) Which of the following decomposed tables satisfy BCNF properties ?

?

(Needs picture) Match the following

?

Find out candidate key for the following relation R(A, B, C, D, E, F) with functional dependencies A -> C C -> D D -> B E -> F

AE+

Specialization is _____ process

Top Down

The column of a table if referred as __________ ?

Attribute

The set of permitted values for each attribute is called its _______ ?

Domain

Which of the following is/are true when you group the employees entity to create various types of employees subtypes ? a) It avoids unnecessary nulls in the employee attributes when some employees have characteristics that are not shared by other employees b) It enables a particular employee type to participate in relationships that are unique to that employee type

a and b

Which of the following properties of relationships are true ?* a) Should clearly identify relationship participants b) Should clearly define participation and cardinality rules

a and b

Which of the following characteristic of primay key is/are true ? a) unique b) intelligent c) no change over time

a and c

Denormalization increases data redundancy ? T/F

True

EERM adds semantiv constructs to original ER model. T/F

True

Normalization is a process for evaluating and correcting table structures ?

True

Surrogate key is system generated key. T/F

True

The procedure produces lower normal forms ?

Denormalization

Generalization is ______ process ?

Bottom Up

Expansion of EERM is _________ ?

Extended Entity Relationship Model

Attribute names can be a reserved word. T/F

False

Surrogate key is applied only when the length of the primary key is too big. T/F*

False

The property of inheritance enables an entity supertype to inherit the attributes and relationships of the subtype. T/F

False

In airline reservation system the entities are date, flight number, place of dep, destination, type of plane and seats availble. The primary key is _______?*

Flight number

An attribute of one key matching the primary key of another table, is called _____ ?

Foreign Key

Entity cluster represents ?

Multiple entities and relationships in ERD

A relation in BCNF is also in 3NF. T/F

True

A subtype discriminator is the attribute in the supertype entity that determines to which subtype the supertype occurrence is related ? T/F

True

All entity subtyped inherit their primary key attribute from their supertype ? T/F

True

Entity Subtype contains ___________ characteristics ?

Unique

Entity super type contains _____ characteristics ?

Unique