B Operating System Dependent Variables

This appendix contains the z/OS-specific allowed, default, and maximum values for Oracle initialization and storage parameters. For a complete discussion of these parameters, refer to Oracle Database Reference. To find out which parameters described in Oracle Database Reference are supported or not supported by Oracle Database for z/OS, refer to Oracle Database Installation Guide for IBM z/OS

The topics in this appendix include:

Initialization Parameters with z/OS-Specific Defaults or Limits
Database Limits
SQL Language Parameters
Storage Parameters

B.1 Initialization Parameters with z/OS-Specific Defaults or Limits

The following table lists the Oracle Database initialization parameters that have z/OS-specific defaults or limits. You can separate the keywords with commas or blanks. For more information, refer to the section "Oracle Initialization Parameter Considerations" in Chapter 3, "Configuring a Database Service and Creating a New Database".

Table B-1 Initialization Parameters with z/OS-Specific Defaults or Limits

Parameter	Default	Maximum	Minimum
ASM_DISKSTRING	None	Not supported	Not supported
AUDIT_FILE_DEST^Foot 1	0 (zero) means "do not write SMF records"	255	128
AUDIT_TRAIL¹	N/A	N/A	N/A
BACKGROUND_CORE_DUMP	None	Not supported	Not supported
BACKGROUND_DUMP_DEST	None	Not supported	Not supported
BITMAP_MERGE_AREA_SIZE	N/A	Limited by address space size	0
COMMIT_POINT_STRENGTH	1	N/A^Foot 2	N/A
CONTROL_FILES¹	&ORAPREFD..&ORASRVN..DFLCNTL.DBF	N/A	N/A
CORE_DUMP_DEST	None	Not supported	Not supported
CPU_COUNT	N/A	N/A	N/A
CREATE_BITMAP_AREA_SIZE	N/A	Limited by address space size	65,536
DB_nK_CACHE_SIZE	0 - only 4, 8, 16, and 32 are supported for n	Limited by address space size	0
DB_BLOCK_BUFFERS	N/A	Limited by address space size	N/A
DB_BLOCK_SIZE¹	4096	32768	4096
DB_CREATE_FILE_DEST¹	N/A	23	N/A
DB_CREATE_ONLINE_LOG_DEST_n ¹	N/A	29	N/A
DB_FILE_MULTIBLOCK_READ_COUNT	Derived	256	1
DB_FILE_NAME_CONVERT¹	N/A	N/A	N/A
DB_FILES	N/A	65,534	N/A
DB_KEEP_CACHE_SIZE	N/A	Limited by address space size	0
DB_RECYCLE_CACHE_SIZE	N/A	Limited by address space size	0
DBWR_IO_SLAVES	0	N/A	N/A
DG_BROKER_CONFIG_FILEn	&ORAPREFD.&ORASRVN.DRn.DAT	None	None
DISPATCHERS (SESSIONS, CONNECTIONS)	N/A	1	0
HASH_AREA_SIZE	N/A	Limited by address space size	0
INSTANCE_NUMBER	N/A	No limit	0
JAVA_POOL_SIZE	N/A	Limited by address space size	0
LARGE_POOL_SIZE	N/A	Limited by address space size	N/A
LOCK_SGA¹	None	Not supported	Not supported
LOG_ARCHIVE_DEST¹	NULL	None	None
LOG_ARCHIVE_FORMAT¹	"T%T.S%S.R%R"	None	None
LOG_BUFFER	16384	Limited by address space size	N/A
LOG_FILE_NAME_CONVERT¹	N/A	N/A	N/A
MAX_DISPATCHERS	None	1	0
MAX_DUMP_FILE_SIZE	None	Not supported	Not supported
MAX_SHARED_SERVERS	None	Limited by address space size	0
NLS_LANGUAGE	AMERICAN	N/A	N/A
NLS_TERRITORY	AMERICA	N/A	N/A
OBJECT_CACHE_MAX_SIZE_PERCENT	N/A	Limited by address space size	0
OBJECT_CACHE_OPTIMAL_SIZE	N/A	Limited by address space size	10240
OPEN_CURSORS	N/A	Limited by address space size	1
OS_AUTHENT_PREFIX	OPS$	None	None
PARALLEL_EXECUTION_MESSAGE_SIZE	N/A	N/A	N/A
PARALLEL_THREADS_PER_CPU	2	N/A	N/A
PROCESSES	Derived	Limited by address space size	N/A
RECOVERY_PARALLELISM	Number of processors minus 1.	Limited by PARALLEL_ MAX_SERVERS	0
SESSION_CACHED_CURSORS	N/A	Limited by address space size	0
SESSION_MAX_OPEN_FILES	N/A	N/A	N/A
SGA_MAX_SIZE¹	The actual SGA size (This parameter should not be specified on z/OS)	N/A	N/A
SGA_TARGET	0 (SGA tuning disabled)	N/A	64
SHADOW_CORE_DUMP	None	Not supported	Not supported
SHARED_POOL_SIZE	32000000	Limited by address space size	4194304
SORT_AREA_SIZE	N/A	Limited by address space size	N/A
SPFILE¹	N/A	N/A	N/A
STANDBY_ARCHIVE_DEST¹	&ORAPREFD..&ORASRVN..ARCHLOG.	None	None
STREAMS_POOL_SIZE	N/A	Limited by address space size	0
TIMED_OS_STATISTICS	0 (Default is recommended value on z/OS)	N/A	N/A
TRACEFILE_IDENTIFIER¹	N/A	N/A	N/A
TRANSACTIONS_PER_ROLLBACK_SEGMENT	5	34	N/A
USER_DUMP_DEST	None	Not supported	Not supported

^Footnote 1More information on using this parameter can be found in the section "Oracle Initialization Parameter Considerations" in Chapter 3, "Configuring a Database Service and Creating a New Database".

^Footnote 2N/A means that the platform-specific value is the same as the generic value.

B.2 Database Limits

Oracle database files, with exceptions, are limited to 4 GB each in size. The exceptions are as follows:

Control files, which are limited to 20,000 logical blocks of size DB_BLOCK_SIZE
Bigfile tablespace files, which are limited to the lesser of 4 GB blocks of size DB_BLOCK_SIZE, or, the maximum size of an extended-format extended addressability data set (up to 59 volumes or 16, if striping). For more information, refer to the IBM document DFSMS: Using Data Sets.

A maximum of 255 redo log files can be specified for a database.

A database can contain up to 65, 534 datafiles over all tablespaces. A single smallfile tablespace is limited to 4094 datafiles.

B.3 SQL Language Parameters

This section lists the parameters for the CREATE CONTROLFILE and CREATE DATABASE SQL statements that have z/OS-specific defaults or limits.

B.3.1 CREATE CONTROLFILE

The parameters for the CREATE CONTROLFILE SQL statement are listed in the following table:

Table B-2 CREATE CONTROLFILE Parameters with z/OS-Specific Defaults or Limits

Parameter	Default	Maximum	Minimum
CHARACTER SET	WE8EBCDIC1047	N/A	N/A^Foot 1
MAXDATAFILES	32	65534^Foot 2	N/A
MAXINSTANCES	1	15	N/A
MAXLOGFILES	32	256	N/A
MAXLOGMEMBERS	2	5	N/A
MAXLOGHISTORY	100	65534	N/A

^Footnote 1N/A means that the platform-specific value is the same as the generic value.

^Footnote 2Specifying MAXDATAFILES larger than 40,000 requires using a value of 8K or larger for the DB_BLOCK_SIZE initialization parameter.

B.3.2 CREATE DATABASE

The parameters for the CREATE DATABASE SQL statement are listed in the following table:

Table B-3 CREATE DATABASE Parameters with z/OS-Specific Defaults or Limits

Parameter	Default	Maximum	Minimum
CHARACTER SET	WE8EBCDIC1047	N/A	N/A^Foot 1
DATAFILE	Refer to "Oracle Database Files" in Chapter 4, "Defining z/OS Data Sets for the Oracle Database".	N/A	16K or one VSAM control area, whichever is larger
LOGFILE	Refer to "Oracle Database Files" in Chapter 4, "Defining z/OS Data Sets for the Oracle Database".	N/A	N/A
MAXDATAFILES	32	65534^Foot 2	N/A
MAXINSTANCES	1	15	N/A
MAXLOGFILES	32	256	2
MAXLOGMEMBERS	2	5	N/A
MAXLOGHISTORY	N/A	N/A	N/A

^Footnote 1N/A means that the platform-specific value is the same as the generic value.

^Footnote 2Specifying MAXDATAFILES larger than 40,000 requires using a value of 8K or larger for the DB_BLOCK_SIZE initialization parameter.

B.4 Storage Parameters

The maximum values for DATAFILE, MINEXTENTS, NEXT, OPTIMAL, and PCTINCREASE are all limited by file size, which is limited by the size of the disk device.