Over a six-month period, you have been regularly monitoring your four-instance RAC database, which is running on the first 4 nodes of a 6-node cluster, by using ADDM and by monitoring well-known combinations of wait event and statistics in AWR reports.
Two weeks ago, a newer version of your main application went live. Starting last week, you noticed a large increase in CPU time (consumed by the three application services on your RAC database) due to increased workload.
The OLTP and DSS services have not had a decrease in the percentage of time spent using CPU. However, for the BATCH service the percentage of time spent using CPU has gone down and the wait-time percentage has increased.
You want to recommend a tuning exercise to your team. Which two recommendations would you make first, based on the symptoms described? (Choose two.)
A.
Tune SQL from the BATCH service programs because they may benefit from SQL tuning.
B.
The BATCH service programs may scale well and could benefit from adding new database instances on either node 5 or 6, or on both.
C.
Tune SQL for the OLTP and DSS service programs because they may benefit from SQL tuning.
D.
The OLTP and DSS service programs may scale well and could benefit from adding new database instances on either node 5 or 6, or on both.
E.
The OLTP and DSS service programs may scale well and could benefit from adding new database instances on one or both of nodes 5 and 6, and by adding more nodes the SQL for BATCH service programs would perform better due to more CPU power.