QUESTION 1
You notice the performance of the database have degraded because of frequent checkpoints.
Which resolve the issue? (Choose.)
A. Disable Automatic checkpoint Tuning
B. Check the size of the redo log file size and increase the size if it is small
C. Set the Fast_start_mttr_target parameter as per the advice given by the MTTR Advisor
D. Decrease the number of redo log members if there is more than one redo log members available in each redo log group
Correct ANSWER:BC
Explanation/reference:
Checkpoint process: The checkpoint process (CKPT) updates the control file and data file headers with checkpoint information and Signals DBWN To write blocks to disk. Checkpoint information includes the Checkpoint position, SCN, location in online redo log to begin recovery, and so on. CKPT does not write data blocks to data files or redo blocks to online redo log files.
Check Point function: (1) Regular promotion of the DBWN Process writes the dirty block of memory back to the data file and does not lose data when the database fails (2) Reduce the time of instance recovery (3) Ensure that all submitted data is written to the data file during a consistent shutdown
Instance recovery time: Refers to the time required to push the last checkpoint (checkpoint location) of the data file to the latest SCN recorded in the control file. Administrators can control the time by setting the mttr target and resizing the redo log group.
MTTR: Mean time to Repair, that is, the mean duration of repair. Refers to the average repair time for repairable products, which is the time between failure and repair. The shorter the MTTR, the better the recoverability. In the database, you can control the time it takes for a database to perform a crash recovery on a single instance by setting the parameter Fast_start_mttr_target (in seconds).
Fast_start_mttr_targe= non-0 value, enable the Quick Start Checkpoint feature, automatically control the speed of the check point. Fast_start_mttr_targe=0, disable the Quick Start checkpoint feature.
If the redo log file size is too small to switch logs frequently, checkpoints frequently occur, so you can increase the size of the redo log file to reduce the frequency at which checkpoints occur.
Fast_start_mttr_target if the setting is too small, in order to control the instance recovery time of a database singleton, checkpoints must occur frequently to ensure that the modified chunks of memory are regularly written to disk, so you can use the MTTR advisor to set the recommended values. |
QUESTION 2
Identify the memory component from which memory is allocated for:session memory for the shared server, buffers for I/O Slaves Oracle Database Recovery Manager (RMAN) Backup and restore operations
A. Large Pool
B. Redo Log Buffer
C. Database Buffer Cache
D. Program Global Area (PGA)
Correct answer:a
Explanation/reference: Large Pool The Large pool is a optional memory area intended for memory allocations that's larger than is appropriate for the shared P Ool. The large pool can provide large memory allocations for the following: UGA for the shared server and the Oracle XA interface (used where transactions interact with multiple databases) Message buffers used in the parallel Executi On statements Buffers for Recovery Manager (RMAN) I/O slaves By allocating session memory from the LARG e pool for shared SQL, the database avoids performance overhead caused by shrinking the shared SQL cache. By allocating memory in large buffers for RMAN operations, I/O server processes, and parallel buffers, the large pool can Satisfy large memory requests better than the shared pool. |
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