Performance Tuning - Question 115

Which three can you use to monitor locks? (Choose three)

A. V$LOCK

B. DBA_WAITERS

C. V$LOCKED_OBJECT

D. DBA_PENDING_TRANSACTIONS

Answer: A, B, C

Explanation:

All these views can be used to monitor locks. DBA_WAITERS shows all the sessions that are waiting for a lock, but do not hold locks for which another session is waiting. V$LOCKED_OBJECT view lists all locks acquired by every transaction on the system.

Incorrect Answers

D: DBA_PENDING_TRANSACTIONS describes unresolved transactions (either due to failure or if the coordinator has not sent a commit/rollback).

OCP: Oracle 9i Performance Tuning Study Guide, Joseph C. Johnson, p. 468-470

Chapter 9: Tuning Contention