CHP 9

Question 1

Normalization

Answer 1

process of converting complex data structures into simple, stable data structures

Question 2

View integration

Answer 2

combine normalized data requirements from all user interfaces into one consolidated logical database model

Question 3

Primary Key

Answer 3

an attribute (or combination of attributes) whose value is unique across all occurrences of a relation

Question 4

Relational database model

Answer 4

data represented as a set of relatable tables or relations

Question 5

Relation

Answer 5

named 2 dimension table of data. consist of a set of named columns and an arbitrary number of unnamed rows

Question 6

Well-structured relations (table)

Answer 6

relation that contains a min amount of redundancy and allows users to insert, modify, and delete rows w/o error/instances

Question 7

Functional Dependency

Answer 7

constraint b/w 2 attributes in which the value of one attribute is determined by the value of another attribute

Question 8

Second Normal Form (2nf)

Answer 8

if every non-primary key attribute is functionally dependent on the whole primary key

Question 9

Third Normal Form

Answer 9

relation that is in 2NF and has no functional dependencies between 2 or more non-primary key attributes

Question 10

Foreign Key

Answer 10

attribute that appears as a non primary key attribute in one relation and as a primary key attribute in another relation

Question 11

Referential Integrity

Answer 11

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

Question 12

recursive foreign key

Answer 12

foreign key in a relation that references the primary key values of that same relation

Question 13

Synonym

Answer 13

2 different names that are used for the same attribute (emp_id and Emp_No)

Question 14

Homonym

Answer 14

single attribute that is used for 2 or more different attributes (ex account>loan, bank, savings)

Question 15

Field

Answer 15

smallest unit of named application data recognized by system software

Question 16

Data type

Answer 16

coding scheme recognized by system software for representing organizational data

Question 17

Calculated field

Answer 17

field that can be derived from other database fields.

Question 18

Default Value

Answer 18

value a field will assume unless an explicit value is entered for that field

Question 19

Null Value

Answer 19

a special value, distinct from 0, blank, or any other value, that indicates that the value for the field is missing/unknown

Question 20

physical table

Answer 20

a named set of rows and columns that specifies the fields in each row of the table

Question 21

Denormalization

Answer 21

process of splitting/combining normalized relations into physical table based on affinity of use of rows and fields

Question 22

Physical file

Answer 22

named set of table rows stored in a contiguous section of secondary memory

Question 23

File organization

Answer 23

technique for physically arranging the records of a file

Question 24

Pointer

Answer 24

field of data that can be used to locate a related field or row of data

Question 25

Sequential File organization

Answer 25

rows in a file are stored sequence according to a primary key value

Question 26

Indexed file organization

Answer 26

A file organization in which rows are stored either sequentially or nonsequentially, and an index is created that allows software to locate individual rows.

Question 27

Index

Answer 27

A table used to determine the location of rows in a file that satisfy some condition.

Question 28

Secondary key

Answer 28

One or a combination of fields for which more than one row may have the same combination of values.

Question 29

Hashed file organization

Answer 29

file organization in which the address of each row is determined using an algorithm