Intro to Databases Ch. 3 Quiz

Each table _____ represents an attribute. a) Dimension b) Column c) Value d) Row

Column

Character data can contain any character or symbol intended for mathematical manipulation. a) True b) False

False

Only a single attribute, not multiple attributes, can define functional dependence. a) True b) False

False

The SELECT operator yields a vertical subset of a table. a) True b) False

False

The idea of determination is unique to the database environment. a) True b) False

False

The order of the rows and columns is important to the DBMS. a) True b) False

False

The row's range of permissible values is known as its domain. a) True b) False

False

Date attributes contain calendar dates stored in a special format known as the _____ date format. a) Logical b) Calendar c) Julian d) Epoch

Julian

In the relational model, _____ are important because they are used to ensure that each row in a table is uniquely identifiable. a) Logical Structures b) Relations c) Keys d) Indexes

Keys

_____ logic, used extensively in mathematics, provides a framework in which an assertion (statement of fact) can be verified as either true or false. a) Index b) Database c) Predicate d) Relational

Predicate

A _____ is any key that uniquely identifies each row. a) Super key b) Foreign key c) Special key d) Candidate key

Super key

A null is created when you press the Enter key or the Tab key to move to the next entry without making a prior entry of any kind. a) True b) False

True

Depending on the sophistication of the application development software, nulls can create problems when functions such as COUNT, AVERAGE, and SUM are used. a) True b) False

True

Each table in a relational database must have a primary key. a) True b) False

True

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). a) True b) False

True

RDBMSs enforce integrity rules automatically. a) True b) False

True

Relational algebra defines the theoretical way of manipulating table contents using relational operators. a) True b) False

True

The DIFFERENCE operator subtracts one table from the other. a) True b) False

True

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. a) True b) False

True

You can think of a table as a persistent representation of a logical relation. a) True b) False

True