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

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

Which of the following is true regarding a transaction log?

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

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

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

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

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

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

Deadlock is usually handled by detection rather than by prevention.

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?

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

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

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

In a public key encryption algorithm ____.

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

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

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

A private key encryption algorithm ____.

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.

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