Database Management Chapter 2

How do you refer to a column named State in a table named Client?

Client.State

The relationships between tables are implemented through common ____________________.

Columns

A ______________ primary key is composed of more than one column so that the row is unique.

Composite

List at least six of the aggregate functions available in Access.

Count, Sum, Avg, Max, Min, StDev, Var, First, Last

Which operation is performed by the SUBTRACT command in relational algebra?

Difference

A column whose value uniquely identifies a given row in the table is the secondary key.

False

A relational database handles entities, attributes, and relationships by storing each entity in its own row.

False

In a relation, the order of rows is important.

False

In an AND criterion, the overall criterion is true if either of the individual criteria is true.

False

The concept of grouping means that statistics will be calculated for individual records.

False

The field on which records are sorted is called the composite primary key.

False

The primary key of a table is the row or rows that uniquely identify a given column in that table.

False

The relational operators are +, *, %, and /.

False

To select data from more than one table at the same time, you need to perform a make-table query.

False

Which command contains all rows that are common in two tables?

INTERSECT

Which operation will allow you to extract data from more than one table?

Join

Discuss the difference between the major sort key and the minor sort key.

Major (i.e., primary) sort key: first sort field when sorting records by more than one field Minor (i.e., secondary) sort key: second sort field when sorting records by more than one field

What type of query creates a new table using the query results?

Make-Table

A query ___________________ is a DBMS component that analyzes queries and attempts to determine the most efficient way to execute a given query.

Optimizer

In relational algebra, what command causes only certain columns to be included in the new table?

PROJECT

A ____________________ query in Access allows you to enter criterion when you run the query, as opposed to placing it in the design grid.

Parameter

What uniquely identifies a row in a table?

Primary Key

Which of the following is the column or collection of columns that uniquely identifies a given row in that table?

Primary Key

If you are sorting records by more than one field, which field is the more important field?

Primary Sort Key

Which operator is used to concatenate every row in the first table with every row in the second table?

Product

A(n) ____________________ database is a collection of tables.

Relational

Multiple entries in tables are often called ____________________.

Repeating Groups

Based on the table below, which command lists all information from the table concerning the customer with CustomerNum 260?

SELECT Customer WHERE CustomerNum=260 GIVING Answer

To list the records in a query's results in a particular order, you need to ____________________ the records.

Sort

In relational database shorthand, the structure of a relational database is written with the name of the table followed by the columns in the table listed within parentheses.

True

In the Access Query window, the upper portion of the window contains the design grid.

True

The attributes of an entity become the fields or columns in a table.

True

Which term is another word for a row in a table?

Tuple

Which of the following is NOT true about a relation in a two-dimensional table?

Two or more columns can share the same name

Which command creates a table containing all rows that are in either or both of two tables?

UNION

When some of the entries in a structure contain repeating groups and thus are not single-valued, the structure is called a(n) ____________________.

Unnormalized Relation

A(n) ______________ query makes a specified change to all records satisfying the criteria in the query.

Update

What type of query changes data?

Update

When both criteria must be true for the compound criterion to be true, the _______________ operator is being used.

AND

What is the difference between an AND criterion and an OR criterion?

AND must contain both, OR can contain one or the other.

The compound criteria (conditions) are created by using which of the following two keywords?

AND, OR

What type of functions are Count, Sum, Avg, Max, and Min?

Aggregate

In Access, a parameter query allows you to enter criterion when you run the query.

True

List the six properties that define a relation in a two-dimensional table.

1. Values are atomic. 2. Column values are of the same kind. 3. Each row is unique. 4. The sequence of columns is insignificant. 5. The sequence of rows is insignificant. 6. Each column must have a unique name.

Explain what relational algebra is and how it is used.

Theoretical way of manipulating a relational database. Each command ends with a GIVING clause, followed by a table name.

Which of the following is true if two tables have the same number of columns and their corresponding columns represent the same type of data?

They are union compatible

A query is a question represented in a way that the DBMS can recognize and process.

True

A relational database is a collection of tables.

True