Tuning the Database - Expert Oracle RAC Performance Diagnostics and Tuning - page 285

Step 4
To understand the related wait events, it's important to understand the objects involved in the operation. The object
name is visible in the output from Step 2 ( RMQ_MESSAGE ).
Step 5
Once the object name is obtained, the next step is to determine the blocks and the corresponding files involved in
the operation. This information can be obtained either from GV$SESSION or GV$SESSION_WAIT views for any currently
active sessions or from V$ACTIVE_SESSION_HISTORY for historical analysis of the query behavior.
Script: MVRACPDnTap_ashbysqlid.sql
SELECT inst_id,
event,
p1,
p2,
wait_class
FROM gv$active_session_history
WHERE sql_id = '3kvu10uhykg7y'
AND event IS NOT NULL
ORDER BY p2,
p1;
INST_ID EVENT P1 P2 WAIT_CLASS
-------- ------------------------------ -------- -------- -----------------
4 gc current block 3-way 143 49321 Cluster
5 db file sequential read 8 56097 User I/O
4 gc current block 3-way 149 78214 Cluster
5 buffer busy waits 149 78335 Concurrency
5 gc current grant busy 147 82459 Cluster
5 gc current grant busy 147 82467 Cluster
4 gc current block 2-way 145 89124 Cluster
4 gc current block 2-way 145 89483 Cluster
4 gc current block 2-way 140 90641 Cluster
4 gc current block congested 140 90834 Cluster
4 gc current block 2-way 140 90836 Cluster
4 gc current block 2-way 140 90879 Cluster
4 gc current block 2-way 140 90902 Cluster
4 gc current block 2-way 140 90918 Cluster
4 gc current block 2-way 140 90965 Cluster
5 gc current block 2-way 140 90969 Cluster
4 gc current block 2-way 140 90995 Cluster
4 gc current block 2-way 140 91079 Cluster
4 gc current block 2-way 140 91099 Cluster
5 gc current block 2-way 140 91115 Cluster
4 gc current block 2-way 140 91646 Cluster
4 buffer busy waits 147 92416 Concurrency
4 buffer busy waits 147 92419 Concurrency
4 buffer busy waits 147 92424 Concurrency