Chapter 4

________ is a component of the relational data model included to specify business rules to maintain the integrity of data when they are manipulated. Select one: a. Data integrity b. Data structure c. Business integrity d. Business rule constraint

Data integrity

A synonym is an attribute that may have more than one meaning. -- (T/F)

False

A partial functional dependency is a functional dependency in which one or more nonkey attributes are functionally dependent on part (but not all) of the primary key. Select one: a. False b. True

True

A primary key is an attribute that uniquely identifies each row in a relation. Select one: a. False b. True

True

One property of a relation is that each attribute within a relation has a unique name. -- (T/F)

True

When two or more attributes describe the same characteristic of an entity, they are synonyms. Select one: a. True b. False

True

A primary key whose value is unique across all relations is called a(n): Select one: a. foreign global key. b. global primary key. c. enterprise key. d. inter-table primary key.

enterprise key.

A transversal dependency is a functional dependency between two or more nonkey attributes (t/f)

false

A constraint between two attributes is called a(n): Select one: a. functional relation constraint. b. functional relation. c. attribute dependency. d. functional dependency.

functional dependency.

An attribute that may have more than one meaning is called a(n): Select one: a. homonym. b. alias. c. synonym. d. double defined attribute.

homonym.

The entity integrity rule states that: Select one: a. a primary key must have only one attribute. b. no primary key attribute can be null. c. referential integrity must be maintained across all entities. d. each entity must have a primary key.

no primary key attribute can be null.

A functional dependency in which one or more nonkey attributes are functionally dependent on part, but not all, of the primary key is called a ________ dependency. Select one: a. partial key-based b. cross key c. merged relation d. partial functional

partial functional

An attribute (or attributes) that uniquely identifies each row in a relation is called a: Select one: a. duplicate key. b. column. c. foreign field. d. primary key.

primary key.

A two-dimensional table of data sometimes is called a: Select one: a. set. b. relation. c. group. d. declaration.

relation.

Data is represented in the form of: Select one: a. tables. b. data notes. c. chairs. d. data trees.

tables

A referential integrity constraint is a rule that maintains consistency among the rows of two relations -- (T/F)

true

A relation that contains minimal redundancy and allows easy use is considered to be: Select one: a. simple. b. well-structured. c. clean. d. complex.

well-structured.

Data structures include data organized in the form of tables with rows and columns. Select one: a. True b. False

True

A candidate key is an attribute, or combination of attributes, that uniquely identifies a row in a relation. -- (T/F)

True

There can be multivalued attributes in a relation. -- (T/F)

False

Which of the following are properties of relations? Select one: a. There are multivalued attributes in a relation. b. No two rows in a relation are identical. c. Each attribute has the same name. d. All columns are numeric.

No two rows in a relation are identical.

An alternative name for an attribute is called a(n): Select one: a. alternate attribute. b. related characteristic. c. synonym. d. alias.

alias

A primary key that consists of more than one attribute is called a: Select one: a. foreign key. b. composite key. c. multivalued key. d. cardinal key.

composite key.

When all multivalued attributes have been removed from a relation, it is said to be in: Select one: a. first normal form. b. second normal form. c. Boyce-Codd normal form. d. third normal form.

first normal form.

An attribute in a relation of a database that serves as the primary key of another relation in the same database is called a: Select one: a. link attribute. b. foreign attribute. c. link key. d. foreign key.

foreign key