buffer busy global cache

When a session wants to modify a buffer, which is cached in the remote instances, it waits on the buffer busy global cache event. This is similar to buffer busy waits in single instance architecture. This wait happens at cache layer. In other words, the session is waiting for a buffer in local cache, which is busy because it is waiting for a global cache request to complete. The waits at the RAC layer are accounted in the global cache busy wait event. Wait Parameters:

• P1 = File number from which Oracle is reading the block from
• P2 = Block number from the file that Oracle wants to read into a buffer
• P3 = The numeric code indicating the reason

Wait Time:

The wait time is 1 second between timeouts.