1z0-062 Oracle Database 12c: Installation and Administration - Practice Questions

Question 4

You administer an online transaction processing (OLTP) system whose database is stored in Automatic Storage Management (ASM) and whose disk group use normal redundancy.

One of the ASM disks goes offline, and is then dropped because it was not brought online before DISK_REPAIR_TIME elapsed.

When the disk is replaced and added back to the disk group, the ensuing rebalance operation is too slow.

Which two recommendations should you make to speed up the rebalance operation if this type of failure happens again? (Choose two.)

Select all that apply, then click Submit answer.

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Increase the value of the ASM_POWER_LIMIT parameter.
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Set the DISK_REPAIR_TIME disk attribute to a lower value.
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Specify the statement that adds the disk back to the disk group.
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Increase the number of ASMB processes.
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Increase the number of DBWR_IO_SLAVES in the ASM instance.

Reference / correct answer:

Increase the value of the ASM_POWER_LIMIT parameter.

Increase the number of ASMB processes.

A: ASM_POWER_LIMIT specifies the maximum power on an Automatic Storage Management instance for disk rebalancing. The higher the limit, the faster rebalancing will complete. Lower values will take longer, but consume fewer processing and I/O resources.

D:

* Normally a separate process is fired up to do that rebalance. This will take a certain amount of time. If you want it to happen faster, fire up more processes. You tell ASM it can add moreprocesses by increasing the rebalance power.

* ASMB

ASM Background Process

Communicates with the ASM instance, managing storage and providing statistics

Incorrect:

Not B: A higher, not a lower, value of DISK_REPAIR_TIME would be helpful here.

Not E: If you implement database writer I/O slaves by setting the DBWR_IO_SLAVES parameter, you configure a single (master) DBWR process that has slave processes that are subservient to it. In addition, I/O slaves can be used to "simulate" asynchronous I/O on platforms that do not support asynchronous I/O or implement it inefficiently. Database I/O slaves provide non-blocking, asynchronous requests to simulate asynchronous I/O.

Question 5

Which three statements are true about Oracle checkpoint processing? (Choose three.)

Select all that apply, then click Submit answer.

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Frequent thread checkpoints can degrade database performance
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Database Writer (DBWn) processes write checkpoint information to datafile headers and the control file
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It reduces the recovery time from instance failures
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Incremental checkpoints write some dirty buffers to the datafiles and unwritten redo to the online redo logs.
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Thread checkpoints ensure that all dirty buffers are written to data files during a normal shutdown

Question 6

You execute this command:

Which two statements are true about segment space management for segments in this tablespace? (Choose two.)

Select all that apply, then click Submit answer.

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Space utilization inside segments is mapped by bitmaps.
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Segments are automatically shrunk and compressed when rows are deleted.
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The PCTFREE storage parameter has no effect on segments created in this tablespace.
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The PCTUSED storage parameter has no effect on segments created in this tablespace.

1z0-062 – Oracle Database 12c: Installation and Administration