053(九）

41、

41.You have applications that have frequently executed queries, and produce small and static result sets.
You configure the sqlnet.ora file in the client machine to set a nonzero value for the OCI_RESULT_CACHE_MAX_SIZE parameter.
What is the purpose of this configuration?
A. to avoid round trips to the server by enabling caching of query results in client memory
B. to improve performance by storing a copy of the data from the private SQL area of the PGA
C. to enhance the query performance by creating a cache in the client memory for sorting operations
D. to avoid the storing of query plans and results in the server by creating a cache in the client memory

Answer: A

参考：Call Interface Programmer's Guide
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CLIENT_RESULT_CACHE_SIZE
The default value is zero, implying that the client cache feature is disabled. To enable the client result cache feature, set the size to 32768 bytes (32 Kilobytes (KB)) or greater. This is the minimum size of the client per-process result set cache. All OCI client processes get this minimum size. This can be overridden by the sqlnet.ora configuration parameter OCI_RESULT_CACHE_MAX_SIZE only if this feature is enabled on the server by the CLIENT_RESULT_CACHE_SIZE initialization parameter.

42、

42.You plan to use SQL Performance Analyzer to analyze the SQL workload. 
You created a SQL Tuning Set as a part of the workload capturing. 
What information is captured as part of this process? (Choose all that apply.)
A. the SQL text
B. the execution plan
C. the execution context
D. the execution frequency
E. the system change number (SCN)

Answer: ACD

43、

43.View the following SQL statements:
Transaction T1 INSERT INTO hr.regions VALUES (5,'Pole');COMMIT;
Transaction T2 UPDATE hr.regions SET region_name='Poles' WHERE region_id = 5; COMMIT;
Transaction T3 UPDATE hr.regions SET region_name='North and South Poles' WHERE region_id = 5;
You want to back out transaction T2. Which option would you use?
A. It is possible, but transaction T3 also backs out.
B. It is possible with the NOCASCADE_FORCE option.
C. It is possible with the NONCONFLICT_ONLY option.
D. It is not possible because it has conflicts with transaction T3.

Answer: B 

44、

44.You have a very large table that your users access frequently. 
Which of the following advisors will recommend any indexes to improve the performance of queries against this table?
A. The Automatic Memory Manager (AMM)
B. The SQL Tuning Advisor
C. The Segment Advisor
D. The SQL Access Advisor

Answer: D

45、

45.What is the advantage of setting the ASM-preferred mirror read for the Stretch cluster configuration?
A. It improves resync operations.
B. This feature enables much faster file opens.
C. It improves performance as fewer extent pointers are needed in the shared pool.
D. It improves performance by reading from a copy of an extent closest to the node.

Answer: D