Which three options have a RAC-specific tuning component?
A.
contention on index leaf blocks
B.
sequence definitions
C.
the size of the online redo log buffers
D.
contention for online redo log files
E.
contention for archived redo log files
F.
the load on the Cluster Interconnect
Explanation:
A: Contention for data and index blocks in a single instance database will probably magnify in a RAC environment.
C: A typical cause of high latencies is when the LMS process must flush uncommitted changes to the redo log prior to sending the block to the requesting instance.
If the application design is such that uncommitted blocks are often in demand across instances in the cluster then these redo log flushes might become common.
F: Examining the interconnect
When Global Cache waits are high, we should first determine if the latency is primarily the result of interconnect network waits.
http://www.toadworld.com/platforms/oracle/w/wiki/10939.optimizing-oracle-rac#rac-tuning-principles
RAC tuning tips :
1- Index Block Contention
2- Configure the interconnects properly.
3- Increasing sequence caches improves instance affinity to index keys deriving their
values from sequences. That technique may result in significant performance gains for
multi-instance insert-intensive applications.
I think ACF correct
but what about B: sequence definitions any ides?
A, B and F
C, D and F it’s a true when I talk about tuning any type of database instance, but, when I talk about specific RAC tuning, “A”, “B” and “F” is the best answer.
Oracle Database 12c: RAC Administration 8 – 13
Most Common RAC Tuning Tips
Application tuning is often the most beneficial!
• Reduce long full-table scans in OLTP systems.
• Use Automatic Segment Space Management (ASSM).
• Increase sequence caches.
• Use partitioning to reduce interinstance traffic.
• Avoid unnecessary parsing.
• Minimize locking usage.
• Remove unselective indexes.
• Configure interconnect properly.
• Employ In Memory-Parallel Query
Thanks WGCM!
I choose A,B,F
ABF for me