1. Database
by Tanat Tonguthaisri
itpe@nstda.or.th
2. 1. Which of the following is used for
supporting decision making by
organizing, integrating, and accumulating
a large volume of data obtained through
various corporate activities?
a) Data administration
b) Data warehouse
c) Data dictionary
d) Data mapping
3. 2. A hard disk failure occurred on a mail server, and e-mails of
many users were lost. Recovery of data was attempted, but e-
mails sent and received during the two-week period after the last
backup could not be restored because backups were only
created every two weeks. Taking a lesson from this incident, a
measure is to be implemented to allow restoration up to the state
of the day before such a failure. Which of the following is an
appropriate measure?
a) Performing daily incremental backup in addition to biweekly
(every two-week) full backup
b) Accumulating e-mails on multiple different hard disks in a
distributed manner
c) Implementing hard disk mirroring on the mail server for
higher reliability, without changing the existing backup
schedule
d) Storing daily backup onto the same hard disk media, and a
biweekly (every two-week) copy of the backup to another
storage media
4. 3. A program in operation detected that the sales
data exceeded the upper limit. As a result of
checking the input form, it was found that sales
quantity exceeded the upper limit by two digits.
Which of the following is the appropriate action for
the operations department to take toward this data?
a) Correcting the data at the operations department
upon the department head approval
b) Consulting the system development department
c) Discarding such data
d) Asking the department which issued the input form to
check it
5. 4. When relational databases are used,
which of the following is an appropriate
purpose of normalizing data?
a)To guarantee data compatibility between
heterogeneous computers
b)To prevent data duplication as well as
occurrence of inconsistency at the time of
updating data
c) To eliminate characters that cannot be
transmitted when a database is used over a
network
d)To handle data storage areas distributed
over multiple media as a contiguous storage
area
6. 5. Under an environment where several users have
access to a database simultaneously, a user tries to
view the data while another user is updating it. In order
to assure data integrity, which of the following is an
appropriate control method in the database
management system?
a) Interrupting update processing and permitting the
user to view the data
b) Permitting the user to view the latest data while
updating
c) Permitting the user to view the data after
completion of the update
d) Discarding the updated data and permitting the
user to view the data before the update
7. 6. Which of the following is an appropriate
explanation of a commercial database
service?
a)Publishing information collected only from
the commercial field free of charge in the
form of a database
b)Providing professional advice on various
issues that occur when a database is being
designed and built
c) Providing information for profit by creating a
database of information collected in specific
fields
d)Managing user-built databases on behalf of
users, in order to release information to the
public
8. 7. There is an order entry system that is used to enter and
manage orders from customers. A numbering printer is used to
print sequential order numbers on order forms in order of arrival
unless the forms have mistakes such as missing information.
When the order data shown below is entered in this order entry
system, which of the following is the item that should be checked
so as not to enter the duplicate order data?
Order data
Order number Order date Product code Quantity Customer code
a) Customer code
b) Product code
c) Order number
d) Order date
9. 8. Candidates for operating a new business
are selected from all of the employees based
on the conditions below. When a decision
table is used to represent the selection
process, which of the following is the
appropriate “conditions table” to be inserted
into the decision table?
[Conditions for candidates]
(1) The employee has selected “I am interested
in IT” in the questionnaire.
(2) The employee has a score of 85 or higher on
the IT aptitude test.
(3) An employee with a test score lower than 85
can become a substitute candidate if the
employee has worked for five or more years in
the current workplace.
10. Selected “I am interested in IT” in the questionnaire
Scored 85 or higher on the IT aptitude test Conditions table
Has five or more years of working experience in the current workplace
Candidate X – – –
Substitute – X – –
Not applicable – – X X
a) b)
N N Y Y N Y N Y
Y N N Y Y N N –
– Y N – – Y N –
c) d)
Y N N Y Y Y Y N
Y Y N N Y N N –
– – N Y – Y N –
11. 9. In a company which has its offices dispersed in several
buildings, it is decided to construct a relational database to
manage the locations where PCs are installed. “Asset” table,
“Room” table, and “Building” table are created, and these
tables are linked. When new data is entered, data in the
table to be referenced should exist beforehand. Which of the
following is the appropriate sequence of entering data into
each table? Note that the underlined items in each table
indicate the primary keys or the foreign keys.
Asset
PCNo BuildingNo RoomNo ModelName
Room
BuildingNo RoomNo RoomName
Building
BuildingNo BuildingName
a) “Asset” table → “Building” table → “Room” table
b) “Building” table → “Room” table → “Asset” table
c) “Room” table → “Asset” table → “Building” table
d) “Room” table → “Building” table → “Asset” table
12. 10. Which of the following is an
appropriate explanation of the table
obtained when the SELECT
statement shown below is executed?
SELECT Products.Product_code, SUM(Unit_price*Sales_volume)
FROM Products, Sales
WHERE Products.Product_code = Sales.Product_code
GROUP BY Products.Product_code
ORDER BY SUM(Unit_price*Sales_volume)
13. Products Sales
Product_code Product_name Unit_price Customer Product_code Sales_volume
A5023 Shampoo 500 Company K A5023 100
A5025 Rinse 400 Store S A5023 150
A5027 Soap 100 Company K A5025 120
Company K A5027 100
Store S A5027 160
a) A table with 3 rows and 2 columns containing total sales
grouped by product code is obtained.
b) A table with 1 row and 1 column containing total sales
for all products is obtained.
c) A table with 2 rows and 2 columns containing total sales
for each customer is obtained.
d) A table with 15 rows and 2 columns containing a list of
sales grouped by customer and by product code is
obtained.
14. 11. When a database is used, the
execution of a function that can update
information during search may cause data
inconsistencies in the database. Which of
the following is an appropriate function to
prevent this situation?
a) Commitment control
b) Deadlock avoidance
c) Exclusive control
d) Shared access
