Zybook 4-3

Question 1

A ___________ statement erases saved data for zero, one, or many savepoints.

Answer 1

ROLLBACK TO

Question 2

A __________ statement temporarily saves data read and written by a transaction.

Answer 2

SAVEPOINT

Question 3

A ___________ statement erases saved data for exactly one savepoint.

Answer 3

RELEASE SAVEPOINT

Question 4

A _________ statement reverses all changes made by a transaction.

Answer 4

ROLLBACK

Question 5

Application programs run on a client machine. The database runs on a separate server machine. The network between client and server fails, and the database does not respond to any application requests.

Answer 5

Storage media failure

Question 6

The database detects two deadlocked transactions. To break the deadlock, the database rolls back one of the transactions.

Answer 6

Transaction failure

Question 7

Due to a security breach, computer memory is corrupted. After the security breach is resolved, the database administrator restarts the database.

Answer 7

System failure

Question 8

After all updates have been reversed in a rollback, a(n) __________ record is written in the log.

Answer 8

transaction

Question 9

When a transaction deletes a table row, a(n) __________ record is written in the log.

Answer 9

update

Question 10

A(n) __________ record indicates all data is saved from main memory to storage media.

Answer 10

checkpoint

Question 11

A(n) __________ record always appears in the log at the beginning of a transaction.

Answer 11

transaction

Question 12

A(n) __________ record is written in the log whenever an update is reversed during a rollback.

Answer 12

compensation

Question 13

A list of active transactions appears in a(n) __________ record.

Answer 13

checkpoint

Question 14

During the redo phase, what log records remove a transaction from the active transaction list?

Answer 14

Both commit and rollback records

Question 15

During the redo phase, what log records generate a database write?

Answer 15

Both update and compensation (undo) records

Question 16

During the undo phase, the recovery system reads the log in reverse and stops at:

Answer 16

The start record for the last transaction in the active transaction list

Question 17

During the undo phase, the recovery system writes compensation records for:

Answer 17

Transactions that do not commit or roll back following the most recent checkpoint

Question 18

Database availability is:

Answer 18

The percentage of time that a database is responsive to application programs.

Question 19

With a cold backup, recovery from storage media failure reads the log:

Answer 19

From the latest checkpoint

Question 20

With a hot backup, as a transaction executes against the primary database:

Answer 20

Log records are sent to the secondary database.