The practical significance of taking the logical view of a database is that it serves as a reminder of the
simple file concept of data storage.
... [Show More] True
A(n) _______ is an orderly arrangement used to logically access rows in a table.
index
The entity relationship model uses the associative entity to represent a(n) _______ relationship
between two or more entities. M:N
When you define a table's primary key, the DBMS automatically creates a(n) _______ index on the
primary key column(s) you declared. unique
Only a single attribute, not multiple attributes, can define functional dependence. false
A _______ key can be described as a minimal superkey, a superkey without any unnecessary
attributes. candidate
In the entity relationship model, a table row corresponds to an entity instance. True
Each table in a relational database must have a primary key. true
Another name for a composite entity is a(n) _______ entity. bridge
Relationships between entities always operate in one direction. False
Mathematical operators cannot be used to place restrictions on character-based attributes. false
The conceptual model can handle _______ relationships and multivalued attributes. M:N
The entity relationship diagram (ERD) represents the _______ database as viewed by the end user. conceptual _______ expresses the minimum and maximum number of entity occurrences associated with one
occurrence of the related entity. cardinality
Each table _______ represents an attribute. column
A relationship is an association between _______. entities
In a 1:M relationship, to avoid the possibility of referential integrity errors, the data of the "1" side
must be loaded first. True
The order of the rows and columns is important to the DBMS. false
Data type selection is usually dictated by the nature of the data and by the intended use. true
RDBMSs enforce integrity rules automatically. true
A _______ key is defined as a key that is used strictly for data retrieval purposes. secondary
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. (min, max)
Connectivities and cardinalities are established by concise statements known as business rules. true
A _______ is the primary key of one table that has been placed into another table to create a
common attribute. foreign key
A _______ is any key that uniquely identifies each row. superkey
The entity relationship model (ERM) is dependent on the database type. false
A _______ attribute can be further subdivided to yield additional attributes. composite
A _______ attribute is one that cannot be subdivided. simple
In the relational model, _______ are important because they are used to ensure that each row in a
table is uniquely identifiable. keys
A _______ entity has a primary key that is partially or totally derived from the parent entity in the
relationship. weak
Composite attributes make it easier to facilitate detailed queries. false
A composite identifier is a primary key composed of more than one attribute. true
An entity in the entity relationship model corresponds to a table in the relational environment. true
In implementation terms, an entity is existence-dependent if it has a mandatory primary key. false
The existence of a(n) _______ entity indicates that its minimum cardinality is zero. optional
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. True
As rare as 1:1 relationships should be, certain conditions absolutely require their use. True
In a natural join, the column on which the join was made occurs twice in the new table. False
Referential _______ dictates that the foreign key must contain values that match the primary key in
the related table, or must contain null.
Integrity
The Crow's foot symbol with two vertical parallel lines indicates _____ cardinality. (1,1)
A relationship is an association between _____. entities
Knowing the minimum and maximum number of _____ occurrences is very helpful at the application
software level. entity
A weak entity has a primary key that is partially or totally derived from the parent entity in the
relationship. True
In Chen notation, there is no way to represent cardinality. False
Referential integrity and participation are both bidirectional, meaning that they must be addressed in
both directions along a relationship. False
Connectivities and cardinalities are established by concise statements known as business rules. True
A weak relationship exists if the primary key of the related entity contains at least one primary key
component of the parent entity. False [Show Less]