FiltersDone

Question type

Essay

Multiple Choice

Short Answer

True False

Matching

Exam 3: The Relational Database Model

Show Answer

Share

---

All types

Filters

Study FlashcardsPractice ExamLearn

Question 1

Multiple Choice

Review LaterAdd Note

Review Later

_____ returns only the attributes requested, in the order in which they are requested.

A) PROJECT
B) SELECT
C) UNION
D) DIFFERENCE

E) A) and B)
F) B) and C)

Correct Answer

verified

A

Question 2

Multiple Choice

Review LaterAdd Note

Review Later

A _____ is any key that uniquely identifies each row.

A) superkey
B) special key
C) foreign key
D) candidate key

E) A) and B)
F) C) and D)

Correct Answer

verified

A

Question 3

Multiple Choice

Review LaterAdd Note

_____ logic, used extensively in mathematics, provides a framework in which an assertion (statement of fact) can be verified as either true or false.

Each table _____ represents an attribute.

What is a key and how is it important in a relational model?

A(n) _____ only returns matched records from the tables that are being joined.

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

The _____ relationship is the relational database norm.

A _____ contains at least all of the attribute names and characteristics for each table in the system.

A(n) ______ provides a detailed description of all tables found within the user/designer-created database.

Describe the use of the INTERSECT operator.

Only a single attribute, not multiple attributes, can define functional dependence.

According to Codd's _____ rule of relational databases, application programs and ad hoc facilities are logically unaffected when changes are made to the table structures that preserve the original table values (changing order of columns or inserting columns) .

The _____ relationship is the "relational model ideal."

A primary key is a(n) _____ key chosen to be the primary means by which rows of a table are uniquely identified.

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 _____ key can be described as a minimal superkey, a superkey without any unnecessary attributes.

_____ are especially useful when you are trying to determine what values in related tables cause referential integrity problems.

The idea of determination is unique to the database environment.

In a natural join, the column on which the join was made occurs twice in the new table.