Modern Database Management - Chapter 6

Which of the following is true of the order in which SQL statements are evaluated?

The SELECT clause is processed before the ORDER BY clause.

The benefits of a standardized relational language include:

all of the above.

The command for creating a database is:

create schema.

Indexes are created in most RDBMSs to:

provide rapid random and sequential access to base-table data.

A single value returned from an SQL query that includes an aggregate function is called a(n):

scalar aggregate.

The ________ is the structure that contains descriptions of objects such as tables and views created by users.

schema

Which of the following is the wildcard operator in SQL statements?

*

A database table is defined using the data definition language (DDL).

Answer: TRUE

A major benefit of SQL as a standard is reduced training costs.

Answer: TRUE

Adding the DISTINCT keyword to a query eliminates duplicates.

Answer: TRUE

An insert command does not need to have the fields listed.

Answer: TRUE

Applications can be moved from one machine to another when each machine uses SQL.

Answer: TRUE

Expressions are mathematical manipulations of data in a table that may be included as part of the SELECT statement.

Answer: TRUE

The FROM clause is the first statement processed in an SQL command.

Answer: TRUE

The ORDER BY clause sorts the final results rows in ascending or descending order.

Answer: TRUE

Which of the following is a technique for optimizing the internal performance of the relational data model?

Clustering data

Multiple values returned from an SQL query that includes an aggregate function are called:

vector aggregates.

SQL originated from a project called System-S.

Answer: FALSE

________ is a set of commands used to update and query a database.

DML

The CREATE SCHEMA DDL command is used to create a table.

Answer: FALSE

The ALTER TABLE command is used to change a table definition.

Answer: TRUE

A catalog is the structure that contains object descriptions created by a user.

Answer: FALSE

A database is maintained and queried using the data mapping language (DML).

Answer: FALSE

Count(*) tallies only those rows that contain a value, while Count counts all rows.

Answer: FALSE

SQL has been implemented only in the mainframe and midrange environments.

Answer: FALSE

________ is a set of commands used to control a database, which includes security.

DCL

In an SQL statement, which of the following parts states the conditions for row selection?

Where

The SQL command ________ adds one or more new columns to a table.

alter table

Any create command may be reversed by using a ________ command.

drop

A ________ view is materialized when referenced.

dynamic

The first in a series of steps to follow when creating a table is to:

identify each attribute and its characteristics.

Which of the following is a purpose of the SQL standard?

All of the above

A referential integrity constraint specifies that the existence of an attribute in one table depends upon the existence of a foreign key in the same or another table.

Answer: FALSE

A single value returned from an SQL query that includes an aggregate function is called a vector aggregate.

Answer: FALSE

DCL is used to update the database with new records.

Answer: FALSE

Implementation of a standard can never stifle creativity and innovation.

Answer: FALSE

Indexes generally slow down access speed in most RDMS.

Answer: FALSE

Materialized views are stored on disk and are never refreshed.

Answer: FALSE

The DELETE TABLE DDL command is used to remove a table from the database.

Answer: FALSE

The DROP command deletes rows from a table individually or in groups.

Answer: FALSE

The HAVING clause and the WHERE clause perform the same operation.

Answer: FALSE

The ORDER BY clause is the first statement processed in an SQL command.

Answer: FALSE

The comparison operators = and != are used to establish a range of values.

Answer: FALSE

When creating a table, it is not important to consider foreign key—primary key mates.

Answer: FALSE

When the SELECT clause in the create view statement contains the keyword DISTINCT, the view can be used to update data.

Answer: FALSE

If multiple Boolean operators are used in an SQL statement, NOT is evaluated first, then AND, then OR.

Answer: TRUE

In order to update data in SQL, one must inform the DBMS which relation, columns, and rows are involved.

Answer: TRUE

One of the original purposes of the SQL standard was to provide a vehicle for portability of database definition and application modules between conforming DBMSs.

Answer: TRUE

SQL is both an American and international standard for database access.

Answer: TRUE

Some DBMS can handle graphic data types as well as text and numbers.

Answer: TRUE

The SQL command used to populate tables is the INSERT command.

Answer: TRUE

The WHERE clause includes the conditions for row selection within a single table or view and the conditions between tables or views for joining.

Answer: TRUE

The WHERE clause is always processed before the GROUP BY clause when both occur in a SELECT statement.

Answer: TRUE

The asterisk (*) wildcard designator can be used to select all fields from a table as well as in WHERE clauses when an exact match is not possible.

Answer: TRUE

The content of dynamic views is generated when they are referenced.

Answer: TRUE

The views are created by executing a CREATE VIEW SQL command.

Answer: TRUE

When a GROUP BY clause is included in an SQL statement, only those columns with a single value for each group can be included.

Answer: TRUE

When creating tables, it's important to decide which columns will allow null values before the table is created.

Answer: TRUE

Which of the following can produce scalar and vector aggregates?

Group By

Which of the following finds all groups meeting stated conditions?

Having

To get all the customers from Hawaii sorted together, which of the following would be used?

Order By

DDL is typically used during which phases of the development process?

Physical design

Which of the following will produce the minimum of all standard prices?

Select min(standard_price) from Product_V;

A view may not be updated directly if it contains:

all of the above.

The SQL command ________ defines a logical table from one or more tables or views.

create view

To eliminate duplicate rows in a query, the ________ qualifier is used in the SQL Select command.

distinct