BLANK_TRIMMING

Property	Description
Parameter type	Boolean
Default value	false
Modifiable	No
Range of values	true | false
Basic	No

BLANK_TRIMMING specifies the data assignment semantics of character datatypes.

Values:

· TRUE

Allows the data assignment of a source character string or variable to a destination character column or variable even though the source length is longer than the destination length. In this case, however, the additional length over the destination length is all blanks. This value complies with the semantics of SQL92 Transitional Level and above.

· FALSE

Disallows the data assignment if the source length is longer than the destination length and reverts to SQL92 Entry Level semantics.

Note:

1. Query for the current value of the parameter

select name, value, isdefault, isses_modifiable, issys_modifiable,

isinstance_modifiable, isdeprecated, description

from v$parameter where upper(name) = 'BLANK_TRIMMING';

NAME	VALUE	IS DEFAULT	ISSES_ MODIFIABLE	ISSYS_ MODIFIABLE	ISINSTANCE_ MODIFIABLE	IS DEPRECATED	DESCRIPTION
blank_trimming	FALSE	TRUE	FALSE	FALSE	FALSE	FALSE	blank trimming semantics parameter

Oracle initializatoin parameters

BITMAP_MERGE_AREA_SIZE

Property	Description
Parameter type	Integer
Default value	1048576 (1 MB)
Modifiable	No
Range of values	Operating system-dependent
Basic	No

Note:

1. Oracle does not recommend using the BITMAP_MERGE_AREA_SIZE parameter unless the instance is configured with the shared server option. Oracle recommends that you enable automatic sizing of SQL working areas by setting PGA_AGGREGATE_TARGET instead. BITMAP_MERGE_AREA_SIZE is retained for backward compatibility.

2. BITMAP_MERGE_AREA_SIZE is relevant only for systems containing bitmap indexes. It specifies the amount of memory Oracle uses to merge bitmaps retrieved from a range scan of the index. The default value is 1 MB. A larger value usually improves performance, because the bitmap segments must be sorted before being merged into a single bitmap.

3. Related: CREATE_BITMAP_AREA_SIZE

This parameter is not dynamically alterable at the session level.

4. Query for the current value of the parameter

select name, value, isdefault, isses_modifiable, issys_modifiable,

isinstance_modifiable, isdeprecated, description

from v$parameter where upper(name) = 'BITMAP_MERGE_AREA_SIZE';

NAME	VALUE	IS DEFAULT	ISSES_ MODIFIABLE	ISSYS_ MODIFIABLE	ISINSTANCE_ MODIFIABLE	IS DEPRECATED	DESCRIPTION
bitmap_merge_area_size	1048576	TRUE	FALSE	FALSE	FALSE	FALSE	maximum memory allow for BITMAP MERGE

Oracle initializatoin parameters

BACKUP_TAPE_IO_SLAVES

Property	Description
Parameter type	Boolean
Default value	false
Modifiable	ALTER SYSTEM ... DEFERRED
Range of values	true | false
Basic	No

BACKUP_TAPE_IO_SLAVES specifies whether I/O server processes (also called slaves) are used by Recovery Manager to back up, copy, or restore data to tape. When the value is set to true, Oracle uses an I/O server process to write to or read from a tape device. When the value is set to false (the default), Oracle does not use I/O server process for backups. Instead, the shadow process engaged in the backup accesses the tape device.

Note:

1. You cannot perform duplexed backups unless you enable this parameter. Otherwise, Oracle returns an error. When this parameter is enabled, Recovery Manager will configure as many server processes as needed for the number of backup copies requested.

2. This parameter was introduced in Oracle 8.0

3. Query for the current value of the parameter

select name, value, isdefault, isses_modifiable, issys_modifiable,

isinstance_modifiable, isdeprecated, description

from v$parameter where upper(name) = 'BACKUP_TAPE_IO_SLAVES';

NAME	VALUE	IS DEFAULT	ISSES_ MODIFIABLE	ISSYS_ MODIFIABLE	ISINSTANCE_ MODIFIABLE	IS DEPRECATED	DESCRIPTION
backup_tape_io_slaves	FALSE	TRUE	FALSE	DEFERRED	TRUE	FALSE	BACKUP Tape I/O slaves

Oracle initializatoin parameters

BACKGROUND_DUMP_DEST

Property	Description
Parameter type	String
Syntax	BACKGROUND_DUMP_DEST = { pathname | directory }
Default value	Operating system-dependent
Modifiable	ALTER SYSTEM
Range of values	Any valid local path, directory, or disk
Basic	No

BACKGROUND_DUMP_DEST specifies the pathname (directory or disc) where debugging trace files for the background processes (LGWR, DBWn, and so on) are written during Oracle operations.

An alert file in the directory specified by BACKGROUND_DUMP_DEST logs significant database events and messages. Anything that affects the database instance or global database is recorded here. The alert file is a normal text file. Its filename is operating system-dependent. For platforms that support multiple instances, it takes the form alert_sid.log, where sid is the system identifier. This file grows slowly, but without limit, so you might want to delete it periodically. You can delete the file even when the database is running.

Note:

1. This parameter is ignored by the new diagnosability infrastructure introduced in Oracle Database 11g Release 1, which places trace and core files in a location controlled by the DIAGNOSTIC_DEST initialization parameter.

2. Related: USER_DUMP_DEST

BACKGROUND_CORE_DUMP

SHADOW_CORE_DUMP

This parameter is deprecated in 11g due to a new diagnostic / trace infrastructure. See Note 422893.1 for more details of the new diagnostic repository.

3. In some error cases a trace file may be written before BACKGROUND_DUMP_DEST has been determined properly. In this case traces may be written to the $ORACLE_HOME/rdbms/log directory instead.

% cd $ORACLE_HOME/rdbms/log % ls -l total 2 -rw-r--r-- 1 oracle dba 116 Sep 15 09:52 dp.log % more dp.log Data Pump default directory object created: directory object name: DATA_PUMP_DIR creation date: 15-SEP-2008 09:52

4. Query for the current value of the parameter

select name, value, isdefault, isses_modifiable, issys_modifiable,

isinstance_modifiable, isdeprecated, description

from v$parameter where upper(name) = 'BACKGROUND_DUMP_DEST';

NAME	VALUE	IS DEFAULT	ISSES_ MODIFIABLE	ISSYS_ MODIFIABLE	ISINSTANCE_ MODIFIABLE	IS DEPRECATED	DESCRIPTION
background_dump_dest	/oracle/admin/mydb/bdump	FALSE	FALSE	IMMEDIATE	TRUE	FALSE	Detached process dump directory

BACKGROUND_CORE_DUMP

Property	Description
Parameter type	String
Syntax	BACKGROUND_CORE_DUMP = { partial | full }
Default value	partial
Modifiable	No
Basic	No

BACKGROUND_CORE_DUMP specifies whether Oracle includes the SGA in the core file for Oracle background processes.

Values:

· partial

Oracle does not include the SGA in the core dump.

· full

Oracle includes the SGA in the core dump.

Note:

1. Related:

This parameter can significantly affect the size of the dumped core files. In order to dump FULL core dumps any Unix limits (eg: the Unix coredumpsize OS limit) should also be sufficiently large to dump the Oracle image with the SGA attached.

2. Query for the current value of the parameter

select name, value, isdefault, isses_modifiable, issys_modifiable,

isinstance_modifiable, isdeprecated, description

from v$parameter where upper(name) = 'BACKGROUND_CORE_DUMP';

NAME	VALUE	IS DEFAULT	ISSES_ MODIFIABLE	ISSYS_ MODIFIABLE	ISINSTANCE_ MODIFIABLE	IS DEPRECATED	DESCRIPTION
background_core_dump	partial	TRUE	FALSE	FALSE	FALSE	FALSE	Core Size for Background Processes

Oracle initializatoin parameters