B
Operating System Dependent Variables

This appendix contains the OS/390-specific allowed, default, and maximum values for Oracle initialization and storage parameters. For a complete discussion of these parameters, refer to the Oracle9i Database Reference. To find out which parameters described in Oracle9i Database Reference are supported or not supported by Oracle9i for OS/390, refer to the Oracle9i Enterprise Edition Installation Guide for OS/390.

The topics in this appendix include:

• Initialization Parameters with OS/390-Specific Defaults or Limits

• Database Limits

• SQL Language Parameters

• Storage Parameters

Initialization Parameters with OS/390-Specific Defaults or Limits

Table B-1 Initialization Parameters

Parameter	Default	Maximum	Minimum
COMMIT_POINT_STRENGTH	1	N/A	N/A
DB_BLOCK_SIZE	4096	32768	4096
DB_FILE_MULTIBLOCK_READ_COUNT	Derived	256	1
LOG_BUFFER	16384	Limited by address space size	N/A
NLS_LANGUAGE	AMERICAN	N/A	N/A
NLS_TERRITORY	AMERICA	N/A	N/A
PROCESSES	Derived	Limited by address space size	N/A
SORT_AREA_SIZE	65536	Limited by available session memory	N/A
TRANSACTIONS_PER_ROLLBACK_SEGMENT	5	34	N/A
Note: N/A means that the platform-specific value is the same as the generic value.

You can separate the keywords with commas or blanks.

Database Limits

Except for control files, Oracle database files (including log, tablespace, and other files) are limited to 4 gigabytes each in size. Control files are limited to 20,000 logical blocks of size DB_BLOCK_SIZE.

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 tablespace is limited to 4094 datafiles.

SQL Language Parameters

CREATE CONTROLFILE

Table B-2 CREATE CONTROL FILE Parameters

Parameter	Default	Maximum	Minimum
MAXDATAFILES	32	65534*	N/A
MAXINSTANCES	1	15	N/A
MAXLOGFILES	32	256	N/A
MAXLOGMEMBERS	2	5	N/A
MAXLOGHISTORY	100	65534	N/A
*Specifying MAXDATAFILES larger than 40,000 requires using a database default blocksize (DB_BLOCK_SIZE INITORA parameter value) of 8K or larger. Note: N/A means that the platform-specific value is the same as the generic value.

CREATE DATABASE

Table B-3 CREATE DATABASE Parameters

Parameter	Default	Maximum	Minimum
DATAFILE	Refer to "Oracle Database Files".	N/A	16K or one VSAM control area, whichever is larger
LOGFILE	Refer to "Oracle Database Files".	N/A	N/A
MAXDATAFILES	32	65534*	N/A
MAXINSTANCES	1	15	N/A
MAXLOGFILES	32	256	2
MAXLOGMEMBERS	2	5	N/A
MAXLOGHISTORY	N/A	N/A	N/A
*Specifying MAXDATAFILES larger than 40,000 requires using a database default blocksize (DB_BLOCK_SIZE INITORA parameter value) of 8K or larger. Note: N/A means that the platform-specific value is the same as the generic value.

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.