Which of the following steps should you take to diagnose contention for latches? (Choose two.)
A . Query V$SYSSTAT to see if the latch free event has a high value for the TIME_WAITED column.
B. Query V$SYSTEM_EVENT to see if the latch free event has a high value for the TIME_WAITED column.
C. Query V$LATCH and V$LATCH_CHILDREN based on the results of V$SYSTEM_EVENT.
D . Query V$LATCH and V$LATCH_CHILDREN based on the results of V$SYSTAT.
Explanation:
Answer B and C: The first place to start is in the V$SYSTEM_EVENT view, looking for latch free waits. If the TIME_WAITED column has a high value, then query the V$LATCH and V$LATCH_CHILDREN, if needed, to investigate the specific latch or child latch that is contributing the most to the time waited. 'Query V$SYSSTAT to see if the latch free event has a high value for the TIME_WAITED column' and Query V$LATCH and V$LATCH_CHILDREN based on the results of V$SYSTAT specify an incorrect dynamic performance view for wait events.
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