Oracle 1z0-064 問題集

質問 1：
Which three statements are true about the interpretation of an execution plan? (Choose three.)
A. The cost of the entire plan is indicated by the line with Id 0 and always includes both I/O and CPU resources.
B. 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.
C. A HASH JOIN in the Operation column always implies that two tables are joined by using an equijoin.
D. An INDEX UNIQUE SCAN in the Operation column always implies that only one row will be returned.
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,B,E

質問 2：
You are administrating a database that supports a mixed workload. Given are the details of the workload:
During the day, short transactions and syntactically similar queries are repeatedly issued.
At night, DSS batch queries and jobs are executed with large sort operations.
Examine the parameters set for the database instance:

To automate memory requirements for both workloads, which three changes to parameters would you recommend?
A. Set the SGA_TARGET parameter to the value of the SGA_MAX_SIZE parameter.
B. Set DB_CACHE_SIZE, SHARED_POOL_SIZE, and LARGE_POOL_SIZE to their minimum required values.
C. Set the SGA_TARGET and PGA_AGGREGATE_TARGET parameters to their minimum required values.
D. Set the MEMORY_MAX_TARGET and MEMORY_TARGET parameters to a value greater than the sum of SGA_MAX_SIZE and PGA_AGGREGATE_TARGET.
E. Set the MEMORY_TARGET parameter to the value of SGA_MAX_SIZE.
正解：A,B,C

質問 3：
Which three statements are true about using Real-Time Database Operations? (Choose three.)
A. The CONTROL_MANAGEMENT_PACK_ACCESS initialization parameter must be set to DIAGNOSTIC+TUNUNG to use Real-Time Database Operations.
B. Real-Time Database Operations can be enabled only at the system level.
C. The STATISTICS_LEVEL initialization parameter must be set to ALL to enable automatic SQL monitoring for all long-running queries.
D. The STATISTICS_LEVEL initialization parameter can be set to TYPICAL or ALL to enable Real-Time Database Operations.
E. Database operation monitoring starts automatically when a database operation consumes at least five seconds of the CPU or I/O time in a single execution.
F. Real-Time Database Operations can be created by using the DBMS_MONITOR or DBMS_SESSION packages.
正解：A,C,D

質問 4：
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. Use the DBMS_SPM.ALTER_SQL_PLAN_BASELINE function to alter the accepted plans as fixed plans.
B. Use the DBMS_SPM.EVOLVE_SQL_PLAN_BASELINE function to evolve new plans and fix the plans for the statements.
C. Set the OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES parameter to TRUE.
D. Create a SQL Tuning Set (STS) and run it through the SQL Access Advisor to generate recommendations.
E. Create an STS and run it through the SQL Tuning Advisor to generate recommendations.
F. Gather statistics for the objects used in the queries.
正解：B,D,F

質問 5：
Examine an extract from a PGA Memory Advisory for your database:

Which two inferences are correct? (Choose two.)
A. The current PGA size is sufficient and does not require the memory manager to allocate more memory.
B. The current PGA size requires the use of a temporary tablespace for sorting operations.
C. Automatic management of PGA memory is disabled.
D. PGA size should be increased at least four times its current size for significant improvement in performance and disk space management.
正解：B,D

質問 6：
Examine the Load Profile and partial Top 10 Foreground Events by Total Wait Time sections from an AWR report.


Which two areas should you examine next to identify possible bottlenecks?
A. the application code because user calls are performing several queries that require sorting
B. the "SQL ordered by Gets" section of the AWR report to check for excessive logical I/O
C. the application code because of CPU-intensive activities
D. the "SQL ordered by Reads" section of the AWR report to check for excessive physical reads
正解：B,C