Identify two reasons for the gc current block busy wait event. (Choose two.)
A.
A block is busy in the local cache.
B.
A block is busy in the remote cache.
C.
The Cluster Interconnect is congested.
D.
Either the local or remote CPUs have too large a run queue.
A,B: The gc current block busy wait event indicates that the access to cached data blocks was delayed because they were busy either in the remote or the local cache.
Correct: A,B
The gc current block busy wait event indicates that the access to cached data blocks was delayed because they were busy either in the remote or the local cache. (ora doc B28359_01)
Correct A,B
The gc current block busy wait event indicates that the access to cached data blocks was delayed because they were busy either in the remote or the local cache. This could be caused by any of the following:
The blocks were pinned
The blocks were held up by sessions
The blocks were delayed by a log write on a remote instance
A session on the same instance was already accessing a block which was in transition between instances and the current session needed to wait behind it (for example, gc current block busy)
Source:
https://docs.oracle.com/database/121/RACAD/monitor.htm#RACAD721