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Exam 4: Relational Model Characteristics

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Question 51

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All primary key entries are unique, and no part of a primary key may be ____.

A) zero
B) a foreign key
C) null
D) a candidate key

E) None of the above
F) All of the above

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Question 52

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

A) outer
B) inner
C) direct
D) union

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

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Question 53

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The DIFFERENCE operator subtracts one table from the other.

Another name for a composite entity is a ____ entity.

A(n) ____________________ is an orderly arrangement used to logically access rows in a table.

____________________ is the real power behind the relational database, allowing the use of independent tables linked by common attributes.

Fortunately, the problems inherent in the ____________________ relationship can easily be avoided by creating a composite entity.

A left outer join on tables CUSTOMER and AGENT yields all of the rows in the CUSTOMER table, including those that do not have a matching value in the AGENT table.

A data dictionary is sometimes described as "the database designer's database" because it records the design decisions about tables and their structures.

____, also known as RESTRICT, yields values for all rows found in a table that satisfy a given condition.

____________________ relationships cannot be implemented as such in the relational model.

____ yields only the rows that appear in both tables.

The ____________________ catalog can be described as a detailed system data dictionary that describes all objects within the database, including data about table names, the table's creator and creation date, the number of columns in each table, the data type corresponding to each column, index filenames, index creators, authorized users, and access privileges.

Numeric data are data on which you can perform meaningful arithmetic procedures.

If the foreign key contains either matching values or nulls, the table that makes use of that foreign key is said to exhibit ____________________ integrity

A(n) ____________________ index is an index in which the index key can have only one pointer value (row) associated with it.

You can think of a table as a persistent representation of a logical relation.

Because the relational model uses attribute values to establish relationships among tables, many database users correctly assume that the term relation refers to such relationships.

In a relational table, each column has a specific range of values known as the ____________________ domain.

A(n) ____ join links tables by selecting only the rows with common values in their common attribute(s) .