You work as a database administrator for Certkiller .com. You find that the database performance degrades while you backup the Certkiller database using Recovery Manager (RMAN). The Certkiller database is running in shared server mode. The database instance is currently using 60% of total operating system memory. You suspect the shared pool fragmentation to be the reason. Which action would you consider to overcome the performance degradation?
A.
Configure Java Pool to cache the java objects.
B.
Configure Streams Pool to enable parallel processing.
C.
Increase Shared Pool size to cache more PL/SQL objects.
D.
Increase Database Buffer Cache size to increase cache hits.
E.
Configure Large Pool to be used by RMAN and shared server.
F.
Increase the total System Global Area (SGA) size to increase memory hits.
Explanation:
When attempting to get shared buffers for I/O slaves, the database does the following:
* If LARGE_POOL_SIZE is set, then the database attempts to get memory from the large pool. If this value is not large enough, then an error is recorded in the alert log, the database does not try to get buffers from the shared pool, and asynchronous I/O is not used.
* If LARGE_POOL_SIZE is not set, then the database attempts to get memory from the shared pool.* If the database cannot get enough memory, then it obtains I/O buffer memory from the PGA and writes a message to the alert.log file indicating that synchronous I/O is used for this backup.
The memory from the large pool is used for many features, including the shared server (formerly called multi-threaded server), parallel query, and RMAN I/O slave buffers.Configuring the large pool prevents RMAN from competing with other subsystems for the same memory. Se the LARGE_POOL_SIZE initialization parameter to configure the large pool. To see in which pool (shared pool or large pool) the memory for an object resides, query $SGASTAT.POOL.
REF.: Oracle(r) 10g Backup and Recovery Guide 11-6 and 11-7