INFO 3233 QUIZZES QUESTIONS AND VERIFIED
ANSWERS
In the context of data models, an entity is a person, place, thing, or event about which
data will be collected and stored. - Answers - True
Each row in the relational table is known as an entity instance or entity occurrence in
the ER model. - Answers - True
M:N relationships are not appropriate in a relational model. - Answers - True
The external model is the representation of the database as "seen" by the DBMS. -
Answers - False
A(n) _____ is a restriction placed on the data. - Answers - constraint
_____ are important because they help to ensure data integrity. - Answers - Constraints
Which of the following is true of business rules? - Answers - They can serve as a
communication tool between the users and designers.
An internal _____ refers to a specific representation of an internal model, using the
database constructs supported by the chosen database. - Answers - schema
A(n) _____ is the conceptual organization of an entire database as viewed by a
database administrator. - Answers - schema
Each row in a relation is called a(n) _____. - Answers - tuple
If the attribute (B) is functionally dependent on a composite key (A) but not on any
subset of that composite key, the attribute (B) is fully functionally dependent on (A). -
Answers - True
The SELECT operator yields a vertical subset of a table. - Answers - False
The DIFFERENCE operator subtracts one table from the other. - Answers - True
In a natural join, the column on which the join was made occurs twice in the new table. -
Answers - False
The DIVIDE operation uses one single-column table (e.g., column "a") as the divisor
and one two-column table (e.g., columns "a" and "b") as the dividend. - Answers - True
ANSWERS
In the context of data models, an entity is a person, place, thing, or event about which
data will be collected and stored. - Answers - True
Each row in the relational table is known as an entity instance or entity occurrence in
the ER model. - Answers - True
M:N relationships are not appropriate in a relational model. - Answers - True
The external model is the representation of the database as "seen" by the DBMS. -
Answers - False
A(n) _____ is a restriction placed on the data. - Answers - constraint
_____ are important because they help to ensure data integrity. - Answers - Constraints
Which of the following is true of business rules? - Answers - They can serve as a
communication tool between the users and designers.
An internal _____ refers to a specific representation of an internal model, using the
database constructs supported by the chosen database. - Answers - schema
A(n) _____ is the conceptual organization of an entire database as viewed by a
database administrator. - Answers - schema
Each row in a relation is called a(n) _____. - Answers - tuple
If the attribute (B) is functionally dependent on a composite key (A) but not on any
subset of that composite key, the attribute (B) is fully functionally dependent on (A). -
Answers - True
The SELECT operator yields a vertical subset of a table. - Answers - False
The DIFFERENCE operator subtracts one table from the other. - Answers - True
In a natural join, the column on which the join was made occurs twice in the new table. -
Answers - False
The DIVIDE operation uses one single-column table (e.g., column "a") as the divisor
and one two-column table (e.g., columns "a" and "b") as the dividend. - Answers - True
