S Tunable Database Parameters

This section describes the tunable Database Parameters.

Note:

Review the Oracle recommended guidelines in setting the SGA_TARGET, SGA_MAX_SIZE and PGA_AGGREGATE_TARGET parameters. The values for these memory parameters can vary significantly based on database server specifications and estimated data volume. For values of PGA_AGGREGATE_TARGET parameter Oracle recommends that they be kept at a minimum of 1024 MB.

Table S-1 Tunable Database Parameters

Category	Parameter Name	Type	Default	Oracle Recommended	Oracle Recommended for Exadata
Parameters affecting database creation (not tunable through the init.ora file)	CHARACTER SET	string	AL32UTF 8	AL32UTF8	AL32UTF8
_	NLS_LENGTH_ SCHEMATICS	string	byte	byte	byte
_	NLS_SORT	binary	binary	binary	binary
_	MAXDATAFILES	integer	254	_	_
_	MASXINSTANCES	integer	1	_	_
_	MAXLOGFILES	integer	32	_	_
_	MAXLOGHISTORY	integer	24794	_	_
_	MAXLOGMEMBERS	integer	2	4	4
_	REDO LOG SIZE	integer	10M	3G	16G
Parameters affecting I/O operation	DB_BLOCK_SIZE	integer	2048	8192	8192
_	DB_FILE_MULTIBLOCK_READ_COUNT	integer	The default value corresponds to the maximum I/O size that can be efficiently performed and is platform-dependent.	32	32
_	DB_FILES	integer	200	_	_
_	DISK_ASYNCH_IO	boolean	TRUE	_	_
_	TAPE_ASYNCH_IO	boolean	TRUE	_	_
_	DB_WRITER_PROCESSES	integer	1	4	4
Parameters affecting resource consumption and parallel operations	FAST_START_ PARALLEL_ ROLLBACK	string	LOW	HIGH	HIGH
_	LOG_BUFFER	integer	7M	10000000	10000000
_	LOG_ CHECKPOINT_ INTERVAL	integer	0	10000	10000
_	LOG_ CHECKPOINT_ TIMEOUT	integer	0	0	0
_	OPEN_CURSORS	integer	50	4096	4096
_	PARALLEL_ EXECUTION_ MESSAGE_SIZE	integer	2148	16384	16384
_	PARALLEL_ MAX_ SERVERS	integer	10 * No of CPUs	Set if you are configuring DOP manually at site and PARALLEL_DEGREE_POLICY is set to MANUAL.	Do not set or change
_	PARALLEL_ MIN_ SERVERS	integer	0	Set if you are configuring DOP manually at site and PARALLEL_DEGREE_POLICY is set to MANUAL.	Do not set or change
_	PROCESSES	integer	150	600	600
_	LARGE_POOL_SIZE	integer	0	512M	_
_	PARALLEL_ MIN_ PERCENT	integer	0	Set if you are configuring DOP manually at site and PARALLEL_DEGREE_POLICY is set to MANUAL.	Do not set or change
_	PARALLEL_ THREADS_ PER_ CPU	integer	2	_	_
Additional needed parameters	OPTIMIZER_MODE	string	ALL_ ROWS	ALL_ ROWS	ALL_ ROWS
_	COMPATIBLE	string	_	11.2.0 (for Oracle 11gR2)	11.2.0 .3.0(if using Oracle 11.2.0.3.0) otherwise 11.2.0.2.0
_	GLOBAL_NAMES	string	FALSE	TRUE	TRUE
_	PRE_PAGE_ SGA	string	FALSE	TRUE	TRUE
_	UNDO_ MANAGEMENT	string	AUTO	AUTO	AUTO
_	UNDO_ TABLESPACE	string	_	Set as Per Site Values	Set as Per Site Values
_	UNDO_RETENTION	integer	900	10800	18000
_	TIMED_STATISTICS	boolean	TRUE	TRUE	TRUE
_	OPTIMIZER_ INDEX_CACHING	integer	0	_	_
_	OPTIMIZER_ INDEX_COST_ADJ	integer	100	30	_
_	QUERY_REWRITE_ ENABLED	string	TRUE	FALSE	FALSE
_	STAR_ TRANSFORMATION_ENABLED	string	FALSE	FALSE	FALSE