SGA and its memory structures:
SGA_MAX_SIZE: Used to Size SGA
DB_BLOCK_SIZE: Size of primary blocks that are used for SYSTEM tablespace.
DB_CACHE_SIZE: Size of cache of standard blocks
DB_KEEP_CACHE_SIZE: Sizes of keep buffer cahce-This is used to keep the blocks in memory which are more likely to be reused.
DB_RECYCLE_CACHE_SIZE: Size of Recycle cache-This is used to remove blocks from memory that have little chance to be reused.
LOG_BUFFER: Number of bytes allocated for redo log buffer.SHARED_POOL_SIZE: Memory allocation for shared pool.
DB_CACHE_ADVICE: The Buffer Cache advisory(BFA) is enabled through this parameter-BFA provides statistics which can be used to size the Db buffer cache.
BACKUP_TAPE_IO_SLAVE and BACKUP_DISK_IO=n: RMAN uses Large pool to store information if the value of BACKUP_TAPE_IO_SLAVE is set to TRUE
OPEN_CURSORS: The number of private SQL AREAs that a user process can allocate.
PGA_AGGREGATE_TARGET: Is set to specify the target aggrgate amount of PGA memory available to the instance.
DBWR_IO_SLAVES: Specifies number of I/O slaves specified by DBWR. Default is 0.
If set to a nonzero value, then No. of I/O slaves used by DBWR, ARCn, LGWR and RMAN is 4.
Note: I/O slaves are used to simulate asynchronous I/O on platform that cannoot do this efficiently.
SQL> sho parameter DBWR_IO_SLAVES
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
dbwr_io_slaves integer 0
BACKUP Related:
1. LOG_ARCHIVE_MAX_PROCESSES: Control maximum number of archiver processes started at insrance start up. When log_archive_start parameter is set to TRUE then instance will startup as many ARCn processes depending on this parameter.
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