Modern Database Management - Chapter 6
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;
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.
A view may not be updated directly if it contains:
all of the above.
The benefits of a standardized relational language include:
all of the above.
The command for creating a database is:
create schema.
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
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?
*
Which of the following is a purpose of the SQL standard?
All of the above
A database table is defined using the data definition language (DDL).
Answer: TRUE
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
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 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
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 ALTER TABLE command is used to change a table definition.
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
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
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
Count(*) tallies only those rows that contain a value, while Count counts all rows.
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
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.