Database Chapter 2

For the relationship represented in the figure below, which is true? EMPLOYEE->O---------------------I<- DEPARTMENT

A department can have more than one employee

Which of the following is NOT a good characteristic of a data name? a. relates to a technical characteristics of the system b. relates to business characteristics c. readable d. repeatable

a. relates to a technical characteristics of a system

In an E-R digram, there are ________ business rule(s) for every relationship a. two b. no c. three d. one

a. two

An entity type whose existence depends on another entity type is called a ________ entity. a. weak b. codependent c. strong d. variant

a. weak

A good data definition will describe all of the characteristics of a data object except: a. subtleties b. who can delete the data c. who determines the value of the data d. examples

b. who can delete the data

The number of entity types that participate in a relationship is called the: a. counter b. number c. degree d. identifying characteristic

c. degree

A relationship between the instances of a single entity type is called a(n) ________ relationship. a. ternary b. primary c. unary d. binary

c. unary

A good data definition will describe all of the characteristics of a data object except: a. Examples b. subtleties c. who can delete the data d. who determines the value of the data

c. who can delete the data

Which of the following conditions should exist if an associative entity is to be created? a. The new associative entity participates in independent relations b. all of the relationships for the participating entities are many to many c. the new associative entity has independent meaning d. all of the above

d. all of the above

Which of the following criteria should be considered when selecting an identifier? a. choose an identifier that will not be null b. choose an identifier that doesn't have large composite attributes c. choose an identifier that is stable d. all of the above

d. all of the above

An attribute that can be calculated from related attribute values is called a(n) ________ attribute. a. multivalued b. simple c. derived d. composite

d. derived