1z1-064 무료 덤프문제 온라인 액세스

Identify two effects of the DB_FILE_MULTIBLOCK_READ_COUNT parameter on the optimizer. (Choose two.)

• A.A full table scan can become cheaper than index scans if the database instance has a high enough DB_FILE MULTIBLOCK_READ_COUNT for both OLTP and DSS workloads.
• B.Decreasing the value of DB_FILE_MULTIBLOCK_READ_COUNT from the default increases the cost of index probes for DSS workloads.
• C.In DSS workloads where full table scans may run in parallel and bypass the buffer cache, decreasing the value of DB_FILE_MULTIBLOCK_READ_COUNT from the default increases the cost of full table scans.
• D.Increasing the value of DB_FILE_MULTIBLOCK_READ_COUNT within OS limits lowers the costing of an index probe that is done in conjunction with a nested loop for OLTP workloads.
• E.Increasing the value of DB_FILE_MULTIBLOCK_READ_COUNT within OS limits lowers the cost of full table scans and can result in the optimizer choosing a full table scan over an index scan for both OLTP and DSS workloads.

Examine the initialization parameters set for a database instance:

The database supports an OLTP workload. Applications connect to the instance using shared server connections and perform small, random I/Os. All the data files are on the same disk. You notice free buffer wait events for sessions in the database instance.
To solve the problem, you increase the size of the buffer cache. But after some time, you notice sessions waiting again on free buffer waits.
What will you recommend to alleviate the issue? (Choose the best answer.)

• A.Run the I/O calibration tool.
• B.Configure the database instance to make asynchronous I/O available to DBWR.
• C.Spread the data files over multiple disks, controllers, and I/O buses to ensure that there are no hotspots in the I/O subsystem.
• D.Configure dedicated server connections for the applications.

Examine the parameters set for your database instance:

You are administrating a database that supports a DSS workload. You make some changes to the sizes of memory components. Consequently, you receive this error:

Which three actions might resolve the issue?

• A.enabling Automatic Shared Memory Management for the database instance
• B.pinning the cursors in the shared pool
• C.enabling Automatic Memory Management for the database instance
• D.setting the PGA_AGGREGATE_TARGET parameter to 0 and the MEMORY_TARGET parameter to the value of the PGA_AGGREGATE_TARGET parameter
• E.increasing the size of the shared pool
• F.setting the value of MEMORY_MAX_TARGET to the value of the SGA_MAX_SIZE parameter

For your database some users complain about not being able to execute transactions. Upon investigation, you find that the problem is caused by some users performing long-running transactions that consume huge amounts of space in the UNDO tablespace.
You want to control the usage of the UNDO tablespace only for these user sessions.
How would you avoid the issue from repeating in future? (Choose the best answer.)

• A.Create external roles to restrict the usage of the UNDO tablespace and assign them to the users.
• B.Set the threshold for UNDO tablespace usage for the users.
• C.Create a profile for the users with the LOGICAL_READS_PER_SESSION and LOGICAL_READS_PER_CALL limits defined.
• D.Implement a Database Resource Manager plan by mapping the users to a resource consumer group with limits defined for UNDO tablespace usage.

Examine the parameters set for a database instance:

The database supports a mixed workload. Users complain about the increased response time of a few DSS queries. During investigation, you execute the query:

Based on the output, which two are possible ways to improve the performance of the queries? (Choose two.)

• A.Increase the value of the PGA_AGGREGATE_TARGET parameter.
• B.Increase the number of DBWn processes.
• C.Enable Automatic Memory Management.
• D.Increase the value of the SGA_TARGET parameter.
• E.Enable Automatic Shared Memory Management.
• F.Enable temporary undo.