Exam 3: The Relational Database Model

Each table in a relational database must have a primary key.

Proper data _____ design requires carefully defined and controlled data redundancies to function properly.

Define entity integrity. What are the two requirements to ensure entity integrity?

The SELECT operator yields a vertical subset of a table.

Dr. Codd's _____ rule of relational database states that every value in a table is guaranteed to be accessible through a combination of table name, primary key value, and column name.

As rare as 1:1 relationships should be, certain conditions absolutely require their use.

Referential _____ dictates that the foreign key must contain values that match the primary key in the related table, or must contain null.

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.

To be considered minimally relational, the DBMS must support the key relational operators _____, PROJECT, and JOIN.

Relational algebra defines the theoretical way of manipulating table contents using relational operators.

When two or more tables share the same number of columns, and when their corresponding columns share the same or compatible domains, they are said to be _____.

In a database context, the word _____ indicates the use of the same attribute name to label different attributes.

The row's range of permissible values is known as its domain.

Date attributes contain calendar dates stored in a special format known as the _____ date format.

In a database context, a(n) _____ indicates the use of different names to describe the same attribute.

The _____ constraint can be placed on a column to ensure that every row in the table has a value for that column.

If one department chair-a professor-can chair only one department, and one department can have only one department chair. The entities PROFESSOR and DEPARTMENT exhibit a(n) _____ relationship.

_____ relationships can be implemented by creating a new entity in 1:M relationships with the original entities.

A table is also called a(n) _____ because the relational model's creator, E. F. Codd, used the two terms as synonyms.

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.