Question 9 Which of the following is an example of lost update? a. The system as

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Question 9 Which of the following is an example of lost update?

a. The system assigns the last aisle seat on a flight to John whereas Peter receives a window seat, although both indicated preference for an aisle seat

b. John and Peter receive each a window seat as they both requested

c. John is initially assigned the last window seat, but this seat is later on assigned to Peter

d. All of the above e. None of the above

Question 8

One of the responsibilities of the data administrator is to establish standards for data naming conventions for the databases in the enterprise.

True

False

Question 7

Which one of the following is the least likely to be viewed as a transaction?

Retrieving a customer's latest purchase

Transferring $1000 from a customer's savings account to the customer's checking account

Reserving a seat on a plane

Reserving a hotel room

e None of the above

Question 6

One of the responsibilities of the data administrator is to monitor the performance of the enterprise's databases.

True

False

Question 5

Which of the following descriptions will usually qualify as a trigger?

The database management system denies inserting a row with a null key and warns the user with an error message

On sale of an item in the supermarket, inventory is updated and management is advised to restock the item

On entering nonexisting department number for a new employee in the table Employee, the database management system denies inserting the new row and warns the user with an error message

On entering nonexisting department number for a new employee in the table Employee, the database management system inserts a null value for the department number and warns the user

e None of the above

Question 4

One of the advantages of concurrency transparency is that relative to the results produced, a transaction takes place as if the transaction was executing alone.

True

False

Question 3

When an update to the database takes place, the time of the update, the values of the data before and after the update, and the type of lock used are recorded in the transaction log.

True

False

Question 2

An example of concurrency transparency would be that multiple students could register for the same course offering at the same time, without interference from each other.

True

False

Question 1

Database management systems used in highly sensitive areas such as national defense and intelligence gathering must be able to support mandatory access controls.

True

False

a.

Retrieving a customer's latest purchase

b.

Transferring $1000 from a customer's savings account to the customer's checking account

c.

Reserving a seat on a plane

d.

Reserving a hotel room

e None of the above

Question 6

One of the responsibilities of the data administrator is to monitor the performance of the enterprise's databases.

True

False

Question 5

Which of the following descriptions will usually qualify as a trigger?

a.

The database management system denies inserting a row with a null key and warns the user with an error message

b.

On sale of an item in the supermarket, inventory is updated and management is advised to restock the item

c.

On entering nonexisting department number for a new employee in the table Employee, the database management system denies inserting the new row and warns the user with an error message

d.

On entering nonexisting department number for a new employee in the table Employee, the database management system inserts a null value for the department number and warns the user

.

e None of the above

Question 4

One of the advantages of concurrency transparency is that relative to the results produced, a transaction takes place as if the transaction was executing alone.

True

False

Question 3

When an update to the database takes place, the time of the update, the values of the data before and after the update, and the type of lock used are recorded in the transaction log.

True

False

Question 2

An example of concurrency transparency would be that multiple students could register for the same course offering at the same time, without interference from each other.

True

False

Question 1

Database management systems used in highly sensitive areas such as national defense and intelligence gathering must be able to support mandatory access controls.

True

False

Explanation / Answer

Q1)

Ans. True

Explanation: The MAC( mandatory access control) model is based on security labels. Subjects are given a security clearance (secret, top secret, confidential, etc.), and data objects are given a security classification (secret, top secret, confidential, etc.). The clearance and classification data are stored in the security labels, which are bound to the specific subjects and objects.

Q2)

Ans. True

Explanation: Here database will proceeding and saving each update without interfering with the other concurrent process which is a classical example of concurrency transparency.

Q3)

Ans. True

Explanation: A transaction log stores old and new data, time, type of lock and also stores information for rollback.

Q4)

Ans. True

Explanation: "Concurrency transparency means relative to the results produced, a transaction takes place as if the transaction was executing alone." <-- It's the standard definition of concurrency transparency.

Q5)

Ans. B)

Explanation: On a sale of an item in the supermarket, inventory is updated and management is advised to restock the item. Here the already stored field is updated and a condition is satisfied to do some action( here advise to restock the item)

Q6)

Ans. True

Explanation: It is one of the responsibilities of DBA to keep eye on the performance of the DBMS.

Q7)

Ans. e) None of the above.

Explanation: Every action mentioned in other options is transaction just some will take more than one database operation while some will take only one operation ( to store or retrieve)

Q8)

Ans. True

Explanation: It's database administrator's responsibility to Design the database, so he will have to decide constraints on naming.

Q9)

Ans. c)

Explanation: Here the window seat is first assigned to John but when Peter tries to book the same seat database allows him to do so. So the update made by John is lost. (To avoid loss of update it should not allow Peter to book that seat (unless Peter is super rich and owns the airline:)))

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