Managing Multiuser Databases – General Questions

1. Locks placed by command are called ________ .

A. implicit locks
B. explicit locks
C. exclusive locks
D. shared locks

Correct Answer:  B. explicit locks

2. Which of the following locks the item from change but not from read?

A. Implicit lock
B. Explicit lock
C. Exclusive lock
D. Shared lock

Correct Answer:  D. Shared lock

3. Which of the following occurs when a transaction rereads data and finds new rows that were inserted by a command transaction since the prior read?

A. Nonrepeatable read
B. Phantom read
C. Dirty read
D. Consistent read

Correct Answer:  B. Phantom read

4. A transaction for which all committed changes are permanent is called:

A. atomic.
B. consistent.
C. isolated.
D. durable

Correct Answer:  D. durable

5. In this instance, dirty reads are disallowed, while nonrepeatable reads and phantom reads are allowed.

A. Read committed
B. Read uncommitted
C. Repeatable read
D. Serializable

Correct Answer:  A. Read committed

Leave A Comment?