Section 15
You need to create a view on the SALES table, but the SALES
table has not yet been created. Which statement is true?
You
must create the SALES table before creating the view.
You can
create the table and the view at the same time using the FORCE option.
You can
use the FORCE option to create the view before the SALES table has been
created. (*)
By
default, the view will be created even if the SALES table does not exist.
Unlike tables, views contain no
data of their own. True or False?
True
(*)
False
Which of the following keywords
cannot be used when creating a view?
HAVING
WHERE
ORDER
BY (*)
They
are all valid keywords when creating views.
In order to query a database
using a view, which of the following statements applies?
The
tables you are selecting from can be empty, yet the view still returns the
original data from those tables.
You can
never see all the rows in the table through the view.
Use
special VIEW SELECT keywords.
You can
retrieve data from a view as you would from any table. (*)
A view can contain group
functions. True or False?
True
(*)
False
Which
action can be performed by using DML statements?
Deleting
records in a table (*)
Altering
a table
Creating
PRIMARY KEY constraints
Disabling
an index
If a database administrator
wants to ensure that changes performed through a view do not violate existing
constraints, which clause should he include when creating the view?
WITH
CONSTRAINT CHECK
WITH
CHECK OPTION (*)
FORCE
WITH
READ ONLY
For a View created using the
WITH CHECK OPTION keywords, which of the following statements are true?
Prohibits
changing rows not returned by the subquery in the view definition. (*)
The
view will allow the user to check it against the data dictionary
Allows
for DELETES from other tables, including ones not listed in subquery
Prohibits
DML actions without administrator CHECK approval
Which option would you use when
creating a view to ensure that no DML operations occur on the view?
WITH
READ ONLY (*)
FORCE
WITH
ADMIN OPTION
NOFORCE
Using the pseudocolumn ROWNUM in
a view has no implications on the ability to do DML's through the view. True or
False?
True
False
(*)
You must create a view that will display the name, customer
identification number, new balance, finance charge, and credit limit of all
customers.
You issue this statement:
CREATE OR REPLACE VIEW CUST_CREDIT_V
AS SELECT c.last_name, c.customer_id, a.new_balance,
a.finance_charge, a.credit_limit
FROM customers c, accounts a
WHERE c.account_id = a.account_id WITH READ ONLY;
Which type of SQL command can be issued on the CUST_CREDIT_V
view?
SELECT
(*)
DELETE
INSERT
UPDATE
The CUSTOMER_FINANCE table
contains these columns:
CUSTOMER_ID NUMBER(9)
NEW_BALANCE NUMBER(7,2)
PREV_BALANCE NUMBER(7,2)
PAYMENTS NUMBER(7,2)
FINANCE_CHARGE NUMBER(7,2)
CREDIT_LIMIT NUMBER(7)
You execute this statement:
SELECT ROWNUM "Rank", customer_id, new_balance
FROM (SELECT customer_id, new_balance FROM customer_finance)
WHERE ROWNUM <= 25
ORDER BY new_balance DESC;
What statement is true?
The
statement failed to execute because an inline view was used.
The 25
greatest new balance values were displayed from the highest to the lowest.
The
statement will not necessarily return the 25 highest new balance values, as the
inline view has no ORDER BY clause. (*)
The
statement failed to execute because the ORDER BY clause does NOT use the Top-n
column.
A Top-N Analysis is capable of
ranking a top or bottom set of results. True or False?
True
(*)
False
When you drop a table referenced
by a view, the view is automatically dropped as well. True or False?
True
False
(*)
Which of the following describes
a top-N query?
A top-N
query returns the top 15 records from the specified table.
A top-N
query returns a result set that is sorted according to the specified column
values.
A top-N
query returns the bottom 15 records from the specified table.
A top-N
query returns a limited result set, returning data based on highest or lowest
criteria. (*)
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