Chapter 5-Normalization

Question 1

Functional Dependency

Answer 1

A relationship between 2 attributes indicating that for each unique attribute A, there is only 1 value of attribute B.

Attribute A - c_id (Attribute A is only associated with one customer name. )

Question 2

Determinant

Answer 2

An attribute or group of attributes on which another attribute is functionally dependent.

C_id-> C_name
Customer ID determines Customer Name

Question 3

Partial functional dependency

Answer 3

B is functionally dependent on A and an attribute can be removed from A and the dependency still exists

Question 4

Transitive dependency

Answer 4

In a functional dependency if B is functionally dependent on A and C is functionally dependent on B, C is then said to be transitively dependent on A

Question 5

BCNF stands for what

Answer 5

Boyce Codd Normal Form

Question 6

What are the three advantages of using views

Answer 6

1. Being able to hide certain parts of the database from users makes it more secure.
2. Views permit customized data access.
3. Views are stored as named database operations so they can be used to keep frequently used or complex data operations ready.

Question 7

Denormalization

Answer 7

The process of rejoining relations that were decomposed during the normalization process to improve performance mainly during query

Question 8

Violation of BCNF criteria occurs if

Answer 8

Relations that have two or more composite candidate keys.

Question 9

DCL stands for what and is used for what purpose.

Answer 9

Data control language is used to control access to the database and to control access to the data with in it such as GRANT or REVOKE privileges.

Question 10

The key to moving 2NF relations into 3NF is…

Answer 10

Removing any transitive dependencies that may exist in the relations.

Question 11

A relation is in 3NF if it is in 2NF and…

Answer 11

No attributes that are not part of the primary key are transitively dependent on the primary key.

Question 12

Atomic value

Answer 12

And attributes value that cannot be divided into multiple pieces of information.

Question 13

A relation is said to be in 2NF If the relation is in 1NF and…

Answer 13

All attributes that are not part of the primary key are completely functionally dependent on the primary key.

Question 14

A relation is in 1NF if…

Answer 14

The data is held in a two-dimensional table with each attribute represented by anatomic value.

Question 15

Decomposition

Answer 15

The process of creating new relations from existing relations based on functional dependencies within the original relation.

Question 16

|

Answer 16

1 and only 1

Question 17

0 |

Answer 17

Zero or more

Question 18

> |

Answer 18

1 or more

Question 19

> 0

Answer 19

0, 1 or more

Question 20

EMPLOYEE         PHONE
\_\_\_\_\_\_\_\_\_\_\_         \_\_\_\_\_\_\_\_
*id.                         *phone_id
f_name.                  home
l_name                    cell
phone_id                 pager

Which is the strong and weak entity?

Answer 20

EMPLOYEE is the strong entity

PHONE is the weak entity