Oracle 1z0-064 問題集

質問 1：
Your database supports an online transaction processing (OLTP) workload. The database uses ASM storage. One of the ASM disks goes offline because of hardware failure. When the disk is replaced and then added back to the diskgroup, database performance is affected by rebalance operations.
Which two actions would you recommend to lower the impact of rebalance operations on the performance of the database? (Choose two.)
A. Decrease the value of the ASM_POWER_LIMIT parameter.
B. Set the DISK_REPAIR_TIME disk attribute to a higher value.
C. Set the DISK_REPAIR_TIME disk attribute to a lower value.
D. Specify the POWER clause with a lower value in an ALTER DISKGROUP statement.
E. Increase the number of ASMB processes.
正解：A,D

質問 2：
You want to capture the performance of your database during the last ten days of the first quarter of the current financial year, so that you can compare this performance against the remaining quarter ends of the current financial year.
Which method should you use? (Choose the best answer.)
A. Create a static baseline that can be used with AWR compare reports.
B. Use fixed baseline templates to create a new moving window baseline and set relevant warning alerts that are computed as a percentage multiple of the maximum value observed for the data in the moving window baseline.
C. Create a new moving window baseline and enable adaptive thresholds for relevant metrics.
D. Use a repeating baseline template to create and drop baselines based on a repeating time schedule and set adaptive thresholds at a high significance level.
正解：B

質問 3：
Your database supports multiple applications. The applications run on the middle tier and use connection pooling for connecting to the database.
You notice that the sessions created by the applications are competing for resources. You want to statistically measure the workload and set priorities.
What action must you perform to achieve this? (Choose the best answer.)
A. Create services for the applications and set a relative priority by assigning them to application users and using the DBMS_MONITOR.SERV_MOD_ACT_TRACE_ENABLE procedure to trace the services.
B. Create services for the applications and set a relative priority by assigning them to application users and using the DBMS_MONITOR.SESSION_TRACE_ENABLE procedure to trace the services.
C. Create services for the applications and set the relative priority of services within an instance by mapping the services directly to consumer groups.
D. Create services for the applications and set a relative priority by assigning them to application users.
正解：A

質問 4：
Your database supports a DSS workload. In an application, a few complex queries that contain multiple functions and expressions are using materialized views. You notice that some queries are performing poorly because they are not benefiting from query rewrites.
Which three actions would you take to improve the performance of queries? (Choose three.)
A. Use the DBMS_ADVISOR.TUNE_MVIEW procedure to get recommendations about rewriting materialized views.
B. Create an STS and submit as input to the SQL Performance Analyzer to get recommendations about improving the performance of queries.
C. Use the DBMS_MVIEW.EXPLAIN_REWRITE procedure to analyze why a query failed to rewrite.
D. Use the DBMS_ADVISOR.QUICK_TUNE procedure to analyze queries based on the usage of query rewrite with materialized views.
E. Create a SQL Tuning Set (STS) and submit as input to the SQL Access Advisor to generate recommendations about query rewrite and fast refresh for materialized views.
正解：B,D,E

質問 5：
You are administering a database that supports an OLTP workload. An application performs a large number of small transactions. Users complain about increased response times for transactions. On investigation, you find that the cache hit ratio is 69%. Examine a partial output from V$SYSTEM_EVENT:

Which four can be possible reasons for the increased response time? (Choose four.)
A. A large number of blocks are fetched from disks frequently.
B. Blocks are aging out of the buffer cache frequently.
C. The database buffer cache is inadequately sized.
D. Several full table scans are performed by transactions.
E. DBWR is not writing the dirty buffers fast enough.
F. Many sessions are waiting for buffers that are currently being read into the buffer cache by other sessions.
正解：A,B,E,F

質問 6：
In which three situations can dynamic statistics be used? (Choose three.)
A. when the sampling time is a small fraction of the total time for a query
B. when a query is on a partitioned table with a global index
C. when an execution plan is suboptimal because of complex predicates
D. when extended statistics are not available for SQL statements that use complex predicates
E. when index statistics are missing on a column that is used in SQL statements with highly selective filters
正解：B,C,D