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