Learn with Oracle : 1z1-064 training material for 100% pass

Which two statements are true about the interpretation of Buffer Cache Hit Ratio in the Instance Efficiency Percentages section of an AWR report? (Choose two.)

• A. Poor hit ratios indicate that a large number of indexed lookups or small table scans are being performed.
• B. A high value indicates that the buffer cache is adequately sized for the current workload.
• C. A high hit ratio may indicate that repeated scanning of the same large table or index is being performed.
• D. A low hit ratio does not necessarily imply that increasing the size of the buffer cache will improve performance.
• E. A low hit ratio indicates that a KEEP buffer pool should be configured based on the size of the largest object accessed in the buffer cache.

Examine the command to change a parameter value from the default to 50:
SQL> ALTER SYSTEM SET OPTIMIZER_INDEX_COST_ADJ = 50;
What is the effect of changing the value of the parameter? (Choose the best answer.)

• A. It influences the optimizer to use bitmap indexes as the estimated cost of conversion from bitmap to rowid is reduced.
• B. It influences the optimizer to always use fast full index scans as the estimated cost of using an index is reduced.
• C. It influences the optimizer to use full table scans instead of index scans as the estimated cost of full table scan is reduced.
• D. It influences the optimizer to use indexes instead of full table scans as the estimated cost of using an index is reduced.

Your database supports an OLTP workload where a large number of syntactically similar queries are executed. Examine the Instance Efficiency Percentages in the Automatic Workload Repository (AWR) report of the last hour:

Which two inferences can be drawn from the report?

• A. The CPU is spending more time on pinning cursors in the library cache.
• B. Cursors are not getting shared in the library cache.
• C. The database buffer cache is undersized and is causing contention.
• D. The optimizer is waiting for resources during parsing of the queries.

Examine the parameters set for your database instance:

You upgrade your database to Oracle Database 12c. The database supports a mixed workload and works with different workloads at different times. You notice in an ADDM report that the shared pool is inadequately sized. You resize the shared pool by decreasing the sizes of other pools, which results in inadequate sizes for other pools. You want to automate the sizing of SGA components.
Which two actions should you perform? (Choose two.)

• A. Set the PGA_AGGREGATE_TARGET parameter to 0 and the SGA_TARGET parameter to 1.5G.
• B. Set the MEMORY_MAX_TARGET parameter to the sum of DB_CACHE_SIZE, SHARED_POOL, and LARGE_POOL_SIZE.
• C. Set DB_CACHE_SIZE, SHARED_POOL, and LARGE_POOL_SIZE to their minimum required values.
• D. Set the SGA_TARGET parameter equal to SGA_MAX_SIZE.
• E. Set the SGA_TARGET parameter to the sum of DB_CACHE_SIZE, SHARED_POOL, and LARGE_POOL_SIZE.

You want to capture AWR data to monitor performance variation every Monday between 9:00 AM and 12:00 PM for three months and automatically remove the older AWR data every fortnight.
How would you achieve this? (Choose the best answer.)

• A. Create database services and make sure that user connections use them to connect to the database instance.
• B. Create AWR baselines.
• C. Create SQL plan baselines.
• D. Create a single baseline template.
• E. Create repeating baseline templates.