1z1-064試験無料問題集（120題）「Oracle Database 12c: Performance Management and Tuning 認定」

出題：1

You are administering a database that supports a mixed workload. The CURSOR_SHARING parameter is set to the default value. While analyzing the latest Automatic Workload Repository (AWR) report, you find a large number of cursor: pin S wait on X, cursor: pin X wait on S, and library cache mutex waits in the Top 10 foreground events section. Examine the Instance Efficiency Percentages section in the AWR report:

Which three statements are true in this scenario? (Choose three.)

A. The CPU is spending more time in finding cursors in the library cache.

B. Cursors are not getting shared, resulting in a large number of hard parses.

C. Sessions are waiting for mutexes in exclusive mode on cursors but other sessions are holding the mutexes in share mode.

D. Sessions are waiting for mutexes in share mode on cursors but other sessions are holding the mutexes in exclusive mode.

E. The buffers required by queries are not found in the buffer cache, thereby increasing expensive disk I/O.

正解：A,C,E 解答を投票する

出題：2

In which three situations does DB time always increase? (Choose three.)

A. when wait time for data to be sent over a network increases

B. when CPU consumption by background processes increases

C. when I/O wait time increases for foreground processes

D. when more connections are made to a database instance

E. when the host is CPU bound for foreground processes

正解：B,C,D 解答を投票する

出題：3

As part of an application upgrade, new objects are being added to an application schem a. You want to check the effect of the new schema objects on the performance of the SQL workload generated by the application.
How would you accomplish this?

A. Capture the workload, set the OPTIMIZER_USE_PENDING_STATISTICS to FALSE, and then replay the workload.

B. Capture the workload in an STS and submit to SQL Tuning Advisor as an input to generate recommendations for indexes and SQL profiles.

C. Set the PUBLISH statistic preference to FALSE, gather statistics, capture the workload in a SQL Tuning Set (STS), and submit the STS to SQL Tuning Advisor.

D. Capture the workload in an STS and submit to SQL Access Advisor as an input to generate recommendations for indexes and materialized views.

正解：D 解答を投票する

出題：4

Which three statements are true about the interpretation of an execution plan? (Choose three.)

A. The ROWS column indicates the cardinality of each operation and is always calculated by dividing the total number of rows in the table by the number of distinct values in the column used in the WHERE clause predicate.

B. An INDEX UNIQUE SCAN in the Operation column always implies that only one row will be returned.

C. The cost of the entire plan is indicated by the line with Id 0 and always includes both I/O and CPU resources.

D. A HASH JOIN in the Operation column always implies that two tables are joined by using an equijoin.

E. A TABLE ACCESS FULL in the Operation column for a query with a WHERE clause occurs only if no index exists for the filter column.

正解：A,C,E 解答を投票する

出題：5

You are administering a database that supports a mixed workload. You upgrade your database from Oracle Database 11g to 12c and after the upgrade, users complain about degraded performance of some queries. The SQL plan baselines imported from the previous version are present for the queries and are loaded to the SQL Management Base as accepted plans. On further investigation, you find that better plans are generated but not used by the optimizer.
Examine the parameters set for the instance:

Which three tasks would you perform to improve the performance of these queries? (Choose three.)

A. Gather statistics for the objects used in the queries.

B. Set the OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES parameter to TRUE.

C. Create a SQL Tuning Set (STS) and run it through the SQL Access Advisor to generate recommendations.

D. Use the DBMS_SPM.ALTER_SQL_PLAN_BASELINE function to alter the accepted plans as fixed plans.

E. Use the DBMS_SPM.EVOLVE_SQL_PLAN_BASELINE function to evolve new plans and fix the plans for the statements.

F. Create an STS and run it through the SQL Tuning Advisor to generate recommendations.

正解：A,C,E 解答を投票する

出題：6

Which two statements are true about gathering statistics? (Choose two.)

A. If an application has only SQL statements with bind variables, it is better to drop existing histograms, disable creation of histograms, and allow the optimizer to select the best execution plans.

B. For each session that is accessing a global temporary table, the optimizer uses only the shared statistics.

C. If end users query newly inserted data, it is possible to get a suboptimal execution plan even if the automatic statistics gathering job is enabled.

D. If concurrent statistics gathering is done by using parallel execution, the Resource Manager should be used for efficient resource management.

正解：B,D 解答を投票する

出題：7

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 the relative priority of services within an instance by mapping the services directly to consumer groups.

C. 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.

D. Create services for the applications and set a relative priority by assigning them to application users.

正解：A 解答を投票する

出題：8

Which four statements are true about Consolidated Database Replay?

A. Consolidated workloads from one or multiple databases can be replayed concurrently on a single system.

B. The number of replay clients must be equal to the number of captured workloads.

C. A subset of the captured workload can be replayed on a test system.

D. Multiple database workloads can be replayed only if both the capture and replay databases are on the same operating system.

E. Multiple database workloads can be replayed only if both the capture and replay databases have the same database version.

F. The replay starts simultaneously for all participating workload captures if no order is defined in the replay schedule.

G. Multiple replay schedules can be defined and any existing replay schedules can also be used.

正解：A,C,F,G 解答を投票する

出題：9

The CUSTOMERS table has 55,500 rows and 620 distinct values in the CUST_CITY_ID column. The number of popular values is 54 and less than 99% of the rows contain popular values.
Which type of histogram should you create to accurately determine the cardinality estimate on the CUST_CITY_ID column?

A. frequency histogram

B. height-balanced histogram

C. high-frequency histogram

D. hybrid histogram

正解：B 解答を投票する

1z1-064試験無料問題集「Oracle Database 12c: Performance Management and Tuning 認定」