B
Logical Names and Parameters

This appendix provides information about Oracle9i logical names and utilities, and the default and recommended values for various initialization parameters. Refer to the Oracle9i Database Administrator's Guide for general information about all the initialization parameters.

This appendix contains the following topics:

• "Oracle9i Logical Names"

• "System-Dependent Initialization Parameters"

B.1 Oracle9i Logical Names

During installation, several logical names are set up. These assignments will be referenced via the ORA_ROOT:[bin]ora_db_logicals.com file that is referenced whenever you start up, upgrade, link, or relink Oracle9i or other Oracle products.

B.1.1 Process Quota Logical Names

If you don't set quotas for Oracle's background processes, Oracle9i uses its own formulas to determine how to set the quota logical names. Table B-1 shows each quota logical name, along with the minimum and maximum values that you can use if you are setting the logical names yourself, as well as the current formula.

Table B-1  Oracle Quota Limits

Quota Logical Name	Minimum	Maximum	Default
PQL$_ASTLM	0	65536	500
PQL$_BIOLM	0	4096	0
PQL$_BYTLM	1024	1024*1024*1024	4000000
PQL$_CPULM	0	0	0
PQL$_DIOLM	0	4096	0
PQL$_ENQLM	256	16000000	50000
PQL$_FILLM	100	65535	30000
PQL$_JTQUOTA	0	0	0
PQL$_PGFLQUOTA	20480	4,194,304	200000
PQL$_PRCLM	0	20	10
PQL$_TQELM	10	2048	100
PQL$_WSDEFAULT	2048	100000	8000
PQL$_WSEXTENT	2048	1,048,576	100000 (Refer to Table B-2 below)
PQL$_WSQUOTA	2048	1,048,576	20000 (Refer to Table B-2 below)
PQL$_LISTEND	0	0	0

In Table B-2, note the following components of the logicals described in Table B-1, and their values or formulas used to calculate the values:

Table B-2  Components of Oracle Logical Names

Calculation Component	Value or Formula
COMFORT_ZONE	2.5 MB
P0_DYNAMIC_SIZE	Process private storage + room for expansion. 20 MB
P0_IMAGE_SIZE	30 MB size of P0 image.
P0_TABLE_SIZE	Size of page tables needed to map SGA.
PQL$_PGFLQUOTA	PAGE_TABLE_SIZE(SGA)+P0_DYNAMIC_SIZE+ COMFORT_ZONE.
PQL$_WSEXTENT	If backing file used: PAGE_TABLE_SIZE (SGA) + 4 * P0_IMAGE_SIZE + P0_DYNAMIC_SIZE + COMFORT_ZONE))/512 + 1 Without backing file used: 4 * (P0_IMAGE_SIZE + P0_DYNAMIC_SIZE + - COMFORT_ZONE))/512 + 1
PQL$_WSQUOTA	If backing file used: (SGA_SIZE/512 + PAGE_TABLE_SIZE (SGA_SIZE) + 4 * (P0_IMAGE_SIZE (PAGE_IMAGE_SIZE) + .6 * (P0_DYNAMIC_SIZE) + COMFORT_ZONE))/512 +1 Without backing file used: PAGE_TABLE_SIZE (SGA_SIZE) + 4 * (PAGE_TABLE_SIZE (P0_IMAGE_SIZE) + .6 * (P0_DYNAMIC_SIZE) + COMFORT_ZONE))/512 +1

For more information about modifying Oracle process quotas through logical names, refer to "Process Quotas" in this guide.

B.2 System-Dependent Initialization Parameters

All parameters used in init.ora require an equal sign (=).  For example, DB_BLOCK_SIZE = 8192 is correct.

B.2.1 BACKGROUND_ DUMP_DEST

Purpose:

Identifies the directory where the trace files created by the detached Oracle9i processes are sent.

Recommended Value:

None.

Default Value:

ORA_ROOT:[admin.<dbname>.bdump] 

Distributed Value:

None.

B.2.2 DB_BLOCK_SIZE

Purpose:

Identifies size (in bytes) of Oracle9i database blocks and the database buffers in the SGA.

Recommended Value:

A binary multiple of 512 bytes (which is the HP OpenVMS Alpha I/O block size). The maximum value is 32768.

Default Value:

8192

Distributed Value:

None

B.2.3 LOG_ARCHIVE_DEST

Purpose:

Specifies a default text string to indicate the location and name of the disk file when archiving log files. Archiving directly to tape is not supported.

Recommended Value:

Any valid disk filename.

Default Value:

ORA_ARCHIVE

Distributed Value:

None

B.2.4 LOG_ARCHIVE_ FORMAT

Purpose:

Specifies a default filename format for archived redo log files. LOG_ARCHIVE_FORMAT is appended to the string specified in the LOG_ARCHIVE_DEST parameter.

The redo log file format specifications can contain variables that are substituted with a unique archived redo log file name. Refer to the "Recovering a Database" chapter of the Oracle9i Database Administrator's Guide for more information on these variables

Recommended Value:

Any valid file name format

Default Value:

ARCH%T_%S.ARC

Distributed Value:

None

B.2.5 PRE_PAGE_SGA

Purpose:

Determines whether the SGA pages will be paged into each user's working set at connect time. This parameter can be manipulated to reduce page faults.

Recommended Value:

Define this parameter as TRUE if the current system load has not produced a high rate of page faults.

Default Value:

False

Distributed Value:

None

B.2.6 SHARED_POOL_SIZE

Purpose:

Determines the size of the shared pool. The shared pool contains shared cursors and stored procedures.

Recommended Value:

Larger values of this parameter improve performance in multi-user systems. Smaller values use less memory. This parameter's minimum is 300 KB and its maximum is determined by the size of your SGA. Although there are no SGA size limitations on HP OpenVMS Alpha, the minimum value is 15 MB.

Default Value:

112 MB

Distributed Value:

None

B.2.7 SORT_AREA_SIZE

Purpose:

Identifies the size of real memory (in bytes) that will be available for sorting processes.

Recommended Value:

The amount of real memory that you can reasonably expect to have available for sorting. For example, on a system with 256 MB of real memory, with 1/8 available to sort processes and 4 sorts occurring at the same time, you might set this parameter to 256/8/4 = 8 MB.

Default Value:

Generally, a larger size only improves the efficiency of large sorts. However, the default is usually fine for most database operations.

Distributed Value:

None

B.2.8 USER_DUMP_DEST

Purpose:

Identifies the location to which trace files created by user processes are sent.

Recommended Value:

None.

Default Value:

ORA_ROOT:[admin.<dbname>.udump]

Distributed Value:

None

B.2.9 VLM_BACKING_STORAGE_FILE

Purpose:

Determines whether to use a backing file for the SGA instead of using a memory resident global section.

Recommended Value:

FALSE, unless there is a well understood need to allow the SGA to page.

Setting this parameter to TRUE will disable the use of OpenVMS Fast I/O, slow process startup, and in most cases reduce performance.

Default Value:

FALSE

Distributed Value:

None