2.4 Multiple Choice
A weak relationship exists if the primary key of the related entity contains at least one primary key component of the parent entity. T/F
False
Composite attributes make it easier to facilitate detailed queries. T/F
False
In Chen notation, there is no way to represent cardinality. T/F
False
In implementation terms, an entity is existence-dependent if it has a mandatory primary key. T/F
False
Referential integrity and participation are both bidirectional, meaning that they must be addressed in both directions along a relationship. T/F
False
Relationships between entities always operate in one direction. T/F
False
Software vendors have adopted the Chen representation because of its compact representation. T/F
False
The Crow's Foot notation easily identifies multivalued attributes. T/F
False
The Crow's Foot notation is less implementation-oriented than the Chen notation.
False
The entity relationship model (ERM) is dependent on the database type.
False
The existence of a mandatory relationship indicates that the minimum cardinality is 0 or 1 for the mandatory entity. T/F
False
The process of database design is a sequential process. T/F
False
A composite identifier is a primary key composed of more than one attribute. T/F
True
A weak entity has a primary key that is partially or totally derived from the parent entity in the relationship. T/F
True
An entity in the entity relationship model corresponds to a table in the relational environment.
True
Connectivities and cardinalities are established by concise statements known as business rules. T/F
True
In a 1:M relationship, to avoid the possibility of referential integrity errors, the data of the "1" side must be loaded first. T/F
True
In the Chen and Crow's Foot notations, an entity is represented with a rectangle containing the entity's name.
True
In the entity relationship model, a table row corresponds to an entity instance.
True
In the original Chen notation, each attribute is represented by an oval with the attribute name connected to an entity rectangle with a line. T/F
True
To implement a small database, a database designer must know the "1" and the "M" sides of each relationship and whether the relationships are mandatory or optional. T/F
True
Unary relationships are common in manufacturing industries. T/F
True
The entity relationship model uses the associative entity to represent a(n) ________ relationship between two or more entities. a. M:N b. 1:M c. N:1 d. M:1
a. M:N
A ________ attribute can be further subdivided to yield additional attributes. a. composite b. simple c. single-valued d. multivalued
a. composite
A(n) ________ is the set of possible values for a given attribute. a. domain b. range c. identifier d. key
a. domain
An entity is said to be ________-dependent if it can exist in the database only when it is associated with another related entity occurrence. a. existence b. relationship c. business d. data
a. existence
Complex ________ requirements may dictate data transformations, and they may expand the number of entities and attributes within the design. a. information b. entity c. design d. processing
a. information
In the entity relationship diagram (ERD), cardinality is indicated using the ________ notation, where max is the maximum number of associated entities and min represents the minimum number of associated entities. a. (max, min) b. (min, max) c. [min ... max] d. {min|max}
b. (min, max)
The conceptual model can handle ________ relationships and multivalued attributes. a. 1:1 b. M:N c. 1:M d. 1:N
b. M:N
The ________ notation of entity-relationship modelling can be used for both conceptual and implementation modelling. a. Bachman b. UML c. Chen d. Crow's Foot
b. UML
To simplify the conceptual design, most higher-order relationships are decomposed into appropriate equivalent ________ relationships whenever possible. a. unary b. binary c. strong d. weak
b. binary
The first step in building an entity-relationship diagram (ERD) is ________. a. developing the initial ERD b. creating a detailed narrative of the organization's description of operations c. identifying the attributes and primary keys that adequately describe the entities d. identifying the business rules based on the description of operations
b. creating a detailed narrative of the organization's description of operations
A derived attribute is indicated in the Chen notation by a ________ that connects the attribute and an entity. a. single line b. dashed line c. double dashed line d. double line
b. dashed line
The decision to store ________ attributes in database tables depends on the processing requirements and the constraints placed on a particular application. a. multivalued b. derived c. single-valued d. composite
b. derived
Ideally, an entity identifier is composed of ________ attribute(s). a. three b. one c. two d. six
b. one
The existence of a(n) ________ entity indicates that its minimum cardinality is zero. a. ternary b. optional c. strong d. weak
b. optional
A ________ attribute is one that cannot be subdivided. a. composite b. simple c. single-valued d. multivalued
b. simple
A ________ entity has a primary key that is partially or totally derived from the parent entity in the relationship. a. strong b. weak c. business d. child
b. weak
The Crow's foot symbol with two vertical parallel lines indicates ________ cardinality. a. (0,N) b. (1,N) c. (1,1) d. (0,1)
c. (1,1)
A ________ relationship exists when three entities are associated. a. unary b. strong c. ternary d. weak
c. ternary
________ expresses the minimum and maximum number of entity occurrences associated with one occurrence of the related entity. a. Connectivity b. Relationship c. Dependence d. Cardinality
d. Cardinality
The entity relationship diagram (ERD) represents the ________ database as viewed by the end user. a. condensed b. physical c. logical d. conceptual
d. conceptual
In organizations that generate large number of transactions, ________ are often a top priority in database design. a. relationships among entities b. logical design standards c. naming conventions d. high processing speeds
d. high processing speeds
If Tiny College has some departments that are classified as "research only" and do not offer courses, the COURSE entity of the college database would be ________ the DEPARTMENT entity. a. existence-dependent on b. independent of c. mandatory for d. optional to
d. optional to
When using the Crow's Foot notation, the associative entity is indicated by ________ relationship lines between the parents and the associative entity. a. dotted b. double c. triple d. solid
d. solid
If an entity can exist apart from all of its related entities, then it is existence-independent, and it is referred to as a(n) ________ entity. a. weak b. alone c. unary d. strong
d. strong
When the specific cardinalities are not included on the diagram in Crow's Foot notation, cardinality is implied by the use of ________. a. symbols b. attributes c. images d. tables
a. symbols
A ________ relationship exists when an association is maintained within a single entity. a. unary b. ternary c. strong d. weak
a. unary
A relationship is an association between ________. a. objects b. entities c. databases d. fields
b. entities
Knowing the minimum and maximum number of ________ occurrences is very helpful at the application software level. a. object b. attribute c. data d. entity
d. entity
If an employee within an EMPLOYEE entity has a relationship with itself, that relationship is known as a ________ relationship. a. self b. self-referring c. looping d. recursive
d. recursive
