Deck 11: Database Control Issues: Security, Backup and Recovery, Concurrency

Question 1

The combination of views and the SQL GRANT command can do all of the following, except ____.

A) limit access to a table
B) limit access to part of a table
C) restrict access to a table to read-only access
D) restrict access to a table to create a new table
E) restrict access to a table to read-only and update access

Answer 1

D

Question 2

All of the following are types of data security breaches, except ____.

A) unauthorized data access
B) unauthorized data modification
C) unauthorized data indexing
D) unauthorized program modification
E) malicious mischief

Answer 2

C

Question 3

Of the following actions or events that can result in a breach of data security, the one that is not necessarily deliberate is ____.

A) unauthorized computer access
B) intercepting data communications
C) spreading computer viruses
D) stealing disks or computers
E) damaging computer hardware

Answer 3

E

Question 4

All of the following are characteristics of backward recovery, except ____.

A) one of the inputs is the last database backup copy
B) one of the inputs is the log starting with the last change to the database
C) one of the inputs is the current database
D) the roll backward program works on a last-in, first-out basis
E) after rolling backward, an automated procedure can roll forward

Question 5

A private key encryption algorithm ____.

A) can be used to encrypt data on a disk but not to encrypt data for transmission over telecommunications lines
B) executes faster than a public key encryption algorithm
C) is asymmetric
D) requires one key for encryption and another key for decryption
E) allows its encryption key to be openly published

Question 6

A biometric security system is associated with ____.

A) something a person knows
B) something a person has
C) some part of a person
D) some item of a person's clothing
E) something a person selects

Question 7

All of the following are true about computer viruses, except ____.

A) they can travel from one computer to another on electric power lines
B) they can travel from one computer to another on diskettes
C) they can travel from one computer to another on telecommunications lines
D) they are capable of copying themselves
E) some are capable of corrupting data

Question 8

All of the following are true about antivirus software, except ____.

A) they use known portions of virus code to recognize known viruses
B) they must continually update their files of known viruses
C) they monitor the computer system for unusual activity
D) they permit software with the proper signatures on file to execute
E) they prevent certain commands from executing without further authorization

Question 9

All of the following are good rules for employees to follow for data security purposes, except ____.

A) don't take diskettes or other storage media out of the building
B) avoid using public key encryption because of the insecure nature of transmitting keys
C) don't write your computer password down anywhere
D) don't respond to any unusual requests for information about the computer system from anyone over the telephone
E) logoff your computer or at least lock your office door when you leave your office, even for just a few minutes

Question 10

Which of the following is true regarding a transaction log?

A) It keeps a record of the program that changed the data and all of the inputs that the program used.
B) It records the value of a piece of data just before it is changed.
C) It records the value of a piece of data just after it is changed.
D) All of the above.
E) None of the above.

Question 11

All of the following are characteristics of forward recovery, except ____.

A) one of the inputs is the last database backup copy
B) one of the inputs is the log starting with the first change to the database after the last backup copy was made
C) one of the inputs is the current database
D) the recovery program makes changes to the backup copy in the same order in which the changes were originally made to the database
E) forward recovery is used to recover a destroyed table or database

Question 12

In Secure Socket Layer (SSL) technology on the World Wide Web ____.

A) the server, using a random number generator, creates a "session key," the key for the private key algorithm with which the secure transaction (the actual online shopping) will be conducted
B) the actual online shopping is conducted with a public key algorithm
C) the key with which the actual online shopping will be conducted is transmitted with a private key algorithm
D) the client sends the server its public key for its public key algorithm
E) a public key algorithm is used to transmit the "session key" for a private key algorithm with which the secure transaction (the actual online shopping) will be conducted

Question 13

Of the following choices, the most advisable location for a mainframe computer or a group of servers in a 20 story office building is ____.

A) the basement
B) the ground floor
C) floors two through eight
D) floors nine through nineteen
E) the top floor (floor twenty)

Question 14

All of the following are rules of thumb regarding creating a password, except ____.

A) it should not be too long
B) it should not be too short
C) it should not be obvious
D) it should have to be written down
E) it should not be too difficult to remember

Question 15

All of the following are true about mirrored databases, except ____.

A) it is not a good idea to have both copies of the database on the same disk
B) two copies of the entire database are maintained and both are updated simultaneously
C) the greater the distance between the two mirrored copies of the database, the greater the security
D) it is a relatively expensive proposition, but allows continuous operation in the event of a disk failure
E) it is an alternative to backward recovery

Question 16

A proxy server ____.

A) is a software firewall that runs on the Web server
B) is designed to use signatures to decide which messages from the World Wide Web to allow to pass
C) is designed to test incoming messages from the World Wide Web and allow valid ones to pass through in their entirety
D) takes apart an incoming message from the World Wide Web and allows only legitimate pieces of data to go to the company's mainframe or application server
E) is built entirely of hardware and does not require specialized software

Question 17

In a public key encryption algorithm ____.

A) the public key is used for encryption and the private key is used for decryption
B) the private key is used for encryption and the public key is used for decryption
C) a private key is used for both encryption and decryption
D) a public key is used for both encryption and decryption
E) a symmetric key is used for both encryption and decryption

Question 18

Recovering from a data entry error discovered a few minutes after it happened can best be accomplished with ____.

A) forward recovery
B) backward recovery
C) mirrored databases
D) hot sites
E) versioning

Question 19

All of the following are methods of breaching data security, except ____.

A) unauthorized computer access
B) intercepting data communications
C) stealing disks or computers
D) spreading computer viruses
E) using public key encryption

Question 20

All of the following are types of data security (prevention) measures, except ____.

A) data encryption
B) wiretaps
C) antivirus software
D) passwords
E) firewalls

Question 21

Passwords should appear on the terminal screen when they are typed in.

Question 22

All of the following are true about deadlock, except ____.

A) deadlock can be detected by a resource usage matrix
B) deadlock can be detected with a timeout
C) the use of locks to prevent the lost update problem can cause deadlock
D) deadlock prevention is difficult
E) locks should never be used because of the potential for deadlock

Question 23

With the combination of the logical view and the SQL GRANT command, users either individually or in groups can be restricted to accessing only certain database tables or only certain data within a database table.

Question 24

A computer virus is a malicious piece of software that has the goal of damaging hardware as a means of breaching data security.

Question 25

Data that has been encrypted has to be decrypted to be used again.

Question 26

The lost update problem can occur when ____.

A) two users are trying to retrieve the same data simultaneously
B) one user is trying to retrieve data and another user is trying to update the same data simultaneously
C) two users are trying to update the same data simultaneously
D) All of the above.
E) None of the above.

Question 27

All of the following are disaster recovery tools or techniques, except ____.

A) totally mirrored systems
B) hot sites
C) cold sites
D) multiple versions
E) reciprocal agreements

Question 28

The SQL GRANT command is used both to control access to the database and to retrieve data.

Question 29

A computer virus attack is the computer version of the old concept of "wiretapping."

Question 30

Stealing disks is a method of breaching computer security.

Question 31

Unauthorized data access and unauthorized data modification are two types of data security breaches.

Question 32

Controlled access to the computer system is a method of breaching security.

Question 33

Passwords should not be so difficult to remember that the person herself has to write them down, which is security exposure in itself because someone else could potentially see it.

Question 34

Damaged hardware can result in unusable or unavailable data.

Question 35

In public key encryption, one key is used to encrypt the data and another key is used to decrypt the data.

Question 36

Biometric systems limit personnel access to computer rooms based on something they know, such as a secret code to be punched in.

Question 37

In public key encryption, the private key is used for encrypting the data and the public key is used for decrypting it.

Question 38

The only use for data encryption is when data is transmitted on a telecommunications line.

Question 39

Using an option of the SQL GRANT command, this person with access to data can in turn grant other people access to the same data.

Question 40

Recommended places to locate a mainframe computer or a cluster of servers include a building's basement and ground floor.

Question 41

Versioning is a way of dealing with concurrent updates without using locks.

Question 42

A hot site consists of hardware similar to yours so that you can be up and running again quickly after a disaster.

Question 43

Grand Travel Airlines has a centralized, mainframe-based information systems environment at its headquarters with telecommunications links to a server at each airport that it services. Each server, in turn, controls a LAN that includes a microcomputer at each check-in counter and gate. Check-in and other data taken in at the counters and gates is immediately transmitted to the mainframe at headquarters. Grand Travel maintains a relational database that includes data about its airplanes, pilots, flights, passengers, and reservations. It takes reservations over the Internet from travel agents and directly from passengers.
a. Devise a data security strategy for Grand Travel Airlines, incorporating appropriate data security measures.
b. Devise a backup and recovery strategy for Grand Travel Airlines. Bear in mind that its reservation system must be constantly operational so that it can check passengers in for flights and so that it does not lose future business.
c. Grand Travel does not wish to overbook its flights. Consider a situation in which there are 23 seats left on a particular flight on a particular date. Reservations agent Miller begins talking to a customer about the flight and reads the record showing 23 seats left. Two minutes later, agent Thompson begins talking to a customer about the very same flight and also reads that there are 23 seats left. Then, agent Miller's customer decides to book 4 seats on the flight, then agent Thompson's customer decides to book 7 seats on the flight.
i. What will happen in the absence of locks?
ii. What can happen in the presence of locks if the two agents are each trying to book multiple flights (or multiple legs of trips) for the two customers and access and lock the flights in different orders? What can be done about this?
iii. How would versioning handle these situations?

Question 44

Backward recovery uses as inputs the log (starting with the last change to the database) and the last backup taken.

Question 45

The usual solution to the lost update problem is to introduce what are known as hardware "locks."

Question 46

Deadlock cannot happen if locks are used to prevent concurrent update problems.

Question 47

Locks should never be used because of the possibility of deadlock.

Question 48

The Central Zoo maintains a modest information systems environment with a server and a LAN that connects all of the zoo's departments. It maintains a relational database that includes data about its animals, employees, members, and about a variety of infrastructure entities including the animals' enclosures.
a. Devise a data security strategy for the Central Zoo, incorporating appropriate data security measures.
b. Devise a backup and recovery strategy for the Central Zoo.
c. While Central Zoo's database is not subject to heavy update activity, it is possible that two employees could try to update the same record at the same time. Devise a strategy that will avoid data problems when this happens.

Question 49

In the "mirrored databases" backup and recovery technique, two copies of the entire database are maintained and both are updated simultaneously.

Question 50

A proxy server is firewall software that resides in the Web server.

Question 51

Forward recovery uses as inputs the log and the last backup taken.

Question 52

The lost update problem can occur when two people attempt to update the same data simultaneously.

Question 53

A basic backup and recovery task is maintaining a disk log or journal of all database data retrieval operations.

Question 54

Forward recovery is used to recreate a table that was destroyed.

Question 55

A transaction log records the value of a piece of data just before it is changed and the value just after it is changed.

Question 56

In Secure Socket Layer (SSL) technology on the World Wide Web, a public key encryption algorithm is used to securely transfer a key for a private key encryption algorithm.

Question 57

A signature is a portion of a computer virus' code that is used by antivirus software to identify it.

Question 58

Deadlock is usually handled by detection rather than by prevention.

Question 59

Backward recovery is an alternative to forward recovery for recreating a table that was destroyed.