You notice that there is a very high percentage of wait time for the gc current split event in your
RAC database that has frequent insert operations.
Which two recommendation would you make to reduce this problem?
A.
shorter transactions
B.
using hash partitioned global indexes
C.
uniform and large extent sizes
D.
automatic segment space management
E.
smaller extent sizes
F.
increasing sequence cache sizes
Index Block Contention: Considerations
Wait events
enq: TX – index contention
gc buffer busy
gc current block busy
gc current split
As a general recommendation, to alleviate the performance impact of globally hot index blocks and leaf block splits, a more uniform, less skewed distribution of the concurrency in the index tree should be the primary objective. This can be achieved by:
• Global index hash partitioning
• Increasing the sequence cache, if the key value is derived from a sequence
• Using natural keys as opposed to surrogate keys
• Using reverse key indexes
D60488GC11
Oracle 11g: RAC and Grid Infrastructure Administration Accelerated
Lesson 14
I think correct answer
B F
+1
As a general recommendation, to alleviate the performance impact of globally hot index blocks and leaf
block splits, a more uniform, less skewed distribution of the concurrency in the index tree should be the primary objective. This can be achieved by:
B) • Global index hash partitioning
F) • Increasing the sequence cache, if the key value is derived from a sequence
• Using natural keys as opposed to surrogate keys
• Using reverse key indexes
gc current split
A is wrong. not too frequent commit
B is right. hash partition
C is wrong.
D is wrong. ASSM not help
E is wrong
F is right. increasing sequence cache size
So B.F are correct