C Initialization Parameters and the Parameter File

Every time SQL*Plus starts an Oracle Database instance, it uses a set of parameters which specify the characteristics of the instance's operation. These parameters are kept in a file, typically named sid.DBS.INIT.ORA.This appendix lists unsupported parameters, and lists other parameters that you may need to change to customize the Oracle Database for the system. Refer to the Oracle Database Reference manual for general descriptions of the parameters listed in this Appendix.

Example Parameter File

The $ORAC1020.DEMO.DBS.INIT.ORA parameter file is created upon initial installation and can be edited as a text file.

Unsupported Parameters

The following initialization file parameters, described in the generic documentation are not supported by Oracle Database 10g for BS2000/OSD.

MAX_DUMP_FILE_SIZE
OS_ROLES
AUDIT_SYSLOG_LEVEL

Specifying these parameters in the initialization file results in an Oracle Database error during startup. The workaround is to remove such lines from the file.

Additional Notes on Initialization Parameters

This section contains additional information on initialization parameters.

BACKGROUND_DUMP_DEST

This parameter specifies the path name (directory or prefix) where debugging trace files for the background processes (LGWR, DBWn, and so on.) are written during Oracle operations. Furthermore, it specifies the path name for the alert file. The default value for this parameter is the current BS2000 user ID of the Oracle background processes. You can specify a prefix for the trace and alert files in the following format:

BACKGROUND_DUMP_DEST=BDD

You can also specify a POSIX directory for this parameter, if you have enabled the POSIX subsystem.

USER_DUMP_DEST

This parameter specifies the path name (directory or prefix) where the server will write debugging trace files on behalf of a user process. The default value for this parameter is the current BS2000 user ID of the Oracle Database processes.

You can specify a prefix for the trace files as follows:

USER_DUMP_DEST=UDD

You can also specify a POSIX directory for this parameter, if you have enabled the POSIX subsystem.

AUDIT_FILE_DEST

This parameter specifies the path name (directory or prefix) into which the audit trail is written when the AUDIT_TRAIL initialization parameter is set to OS. Usually this value is used as a prefix for BS2000 file names. You can also specify a POSIX directory for this parameter, if you have enabled the POSIX subsystem. The default value for this parameter is <sid>.ADUMP. The name of the audit files is <tsn>.<pgm>.AUD, where tsn is the task sequence number of the current task and pgm is the program name. Bear in mind that regardless of whether database auditing is enabled, Oracle/BS2000 always records some database-related actions into the operating system audit file: instance startup, shutdown and connections with administrator privileges.

DB_BLOCK_SIZE

This parameter can have one of the following values:

2K, 4K, 6K, 8K, 16K, 32K, if you use BS2000 2K pubset format.
4K, 8K, 16K, 32K, if you use BS2000 4K pubset format.

DB_FILE_MULTIBLOCK_READ_COUNT

The default value of this parameter is 64K/DB_BLOCK_SIZE, which is also the maximum value. Setting this parameter beyond this limit has no effect.

DB_FILES

If you plan to create a large database, you should set this value to the maximum of 2044 before creating the database.

LOCK_SGA

This parameter is ignored on Oracle Database 10g for BS2000/OSD. Buffers in the SGA are page fixed only during I/O operations. Otherwise, the SGA on BS2000 is pageable.

SGA_MAX_SIZE

This parameter should not be specified on Oracle Database 10g for BS2000/OSD. Because the SGA is not permanently pagefixed as it is on some other systems, there is little benefit in reserving SGA expansion space with the SGA_MAX_SIZE parameter. It will default to the actual SGA size.

LOG_ARCHIVE_BUFFER_SIZE

The value of this parameter should always be set so that when multiplied by the value of SF_PBLKSIZE the result equals 32K.

LOG_ARCHIVE_DEST

This parameter can indicate a pubset, such as LOG_ARCHIVE_DEST=:PUB1:to store all archived redo logs on special media.