1. Locks placed by command are called ________ .
A. implicit locks
B. explicit locks
C. exclusive locks
D. shared 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
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
4. A transaction for which all committed changes are permanent is called:
A. atomic.
B. consistent.
C. isolated.
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