Exam 4: Relational Model Characteristics

The logical view of the relational database is facilitated by the creation of data relationships based on a logical construct known as a(n) ____________________.

The ____________________ relationship is the relational database norm.

____ data can have only a true or false (yes or no) values.

In a relational model, if A determines B, C, and D, you write A = B, C, D.

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

When you define a table's primary key, the DBMS automatically creates a(n) ____ index on the primary key column(s) you declared.

What is a key and why is it important in the relational model?

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

The SELECT operator yields a vertical subset of a table.

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

____________________ joins are especially useful when you are trying to determine what value(s) in related tables cause(s) referential integrity problems.

Tables within a database share common attributes that enable the tables to be linked together.

____ yields a vertical subset of a table.

In an outer join, the matched pairs would be retained and any unmatched values in the other table would be left ____.

Any attribute that is part of a key is known as a ____.

The following example exhibits ____________________ integrity: The CUSTOMER table's primary key is CUS_CODE. The CUSTOMER primary key column has no null entries, and all entries are unique. Similarly, the AGENT table's primary key is AGENT_CODE, and this primary key column also is free of null entries.

The relational database model enables you to view data ____ rather than ____.

RDBMSs enforce integrity rules automatically.

The order of the rows and columns is important to the DBMS.

A(n) ____________________ key can be described as a superkey without unnecessary attributes.