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Oracle8i Database Specifications for Windows NT

Oracle8i uses initialization parameters on Windows NT to enable various features of the database every time an instance is started.

Specific topics discussed are:

• Initialization Parameter File (INIT.ORA) Overview

• Initialization Parameters Without Windows NT-Specific Values

• Calculating Database Limits

Initialization Parameter File (INIT.ORA) Overview

An initialization parameter file is an ASCII text file containing parameters. By changing the parameters and values in an initialization file, you can specify, for example:

• the amount of memory the database uses

• whether to archive filled online redo logs

• which control files currently exist for the database

Every database instance has a corresponding initialization parameter file and ORACLE_SID registry parameter that points to the system identifier (SID) for the instance.

The initialization parameter file name takes the form INIT.ORA. A single instance might have several initialization parameter files, each having some differences that affect system performance.

See: Your INIT.ORA file for initialization parameters set by Oracle Universal Installer during an Oracle8i typical installation type. These parameters may vary, depending on your hardware configuration. Oracle8i Reference for descriptions of all initialization parameters and instructions for setting and displaying their values.

Location of the Initialization Parameter File

By default, Oracle8i uses the initialization parameter files located in ORACLE_BASE\ADMIN\DB_NAME\PFILE, unless you specify a different initialization file with the PFILE option at database startup.

Editing the Initialization Parameter File

To customize Oracle8i database functions, you may need to edit the initialization parameter files. Only use an ASCII text editor to modify the file.

Sample File

A sample file called INITSMPL.ORA is located in the ORACLE_BASE \ADMIN\SAMPLE\PFILE directory.

Note: If you create a database manually using the BUILD_DB.SQL script, you need to create an INIT.ORA file or copy an existing INIT.ORA file and modify the contents. If you use Oracle Database Configuration Assistant to create a database, the INIT.ORA file is automatically created for you.

If you want to use the sample INITSMPL.ORA file as part of database creation:

1. Rename the file INIT.ORA.

2. Edit this file to reflect the correct location of your database control files and the name of your database, as a minimum.

If you installed a starter database, the initialization parameter file INIT.ORA used by the starter database is located in ORACLE_BASE\ADMIN\DB_NAME\PFILE. You can use either INITSMPL.ORA or the starter database INIT.ORA as a basis for creating a new Oracle8i database initialization parameter file.

The annotated, sample initialization parameter file contains alternative values for the initialization parameters. These values and the annotations are preceded by comment signs (#), which prevent them from being processed. To activate a particular parameter, remove the preceding # sign. When you no longer want to use a particular parameter, edit the initialization parameter file to add a comment sign.

For example, several initialization parameters are specified with three different values to create small, medium, or large System Global Areas (SGAs), respectively. The parameter that creates a small SGA is active in the following example:

  db_block_buffers = 200		 # SMALL 

# db_block_buffers = 550		 # MEDIUM 

# db_block_buffers = 3200	 	# LARGE 

To create a medium-sized SGA, comment out the small parameter definition and activate the medium parameter definition. Edit the initialization parameter file as follows:

# db_block_buffers = 200		 # SMALL 

  db_block_buffers = 550		 # MEDIUM 

# db_block_buffers = 3200	 	# LARGE 

Initialization Parameters Without Windows NT-Specific Values

Oracle8i Reference describes the default values for many initialization parameters as being operating system-specific. However, not all the parameters that Oracle8i Reference describes as having operating system-specific values affect Windows NT. In these cases, Windows NT uses either the default value set in the Oracle8i kernel or does not use the parameter. This table describes these initialization parameters:

Parameter	Description
AUDIT_FILE_DEST	Not supported on Windows NT and should not be added to the initialization parameter file.
DB_WRITER_PROCESSES	Not applicable or necessary on Windows NT.
COMPATIBLE_NO_RECOVERY	Uses default value set in Oracle8i kernel (no Windows NT-specific value).
CORE_DUMP_DEST	Not applicable to Windows NT.
CPU_COUNT	Oracle8i automatically sets value to number of CPUs available for your Oracle instance.
HI_SHARED_MEMORY_ADDRESS	Not applicable to Windows NT.
SHARED_MEMORY_ADDRESS	Not applicable to Windows NT.
LARGE_POOL_SIZE	Uses maximum value limited by available memory.
LOG_BUFFER	Starter database uses value set in Oracle8i kernel (no Windows NT-specific value). The Custom database creation option of the Oracle Database Configuration Assistant enables you to customize the value for this parameter.
ORACLE_TRACE_COLLECTION_PATH	Uses default value set in Oracle8i kernel (no Windows NT-specific value).
ORACLE_TRACE_FACILITY_NAME	Uses default value set in Oracle8i kernel (no Windows NT-specific value).
ORACLE_TRACE_FACILITY_PATH	Uses default value set in Oracle8i kernel (no Windows NT-specific value).
SPIN_COUNT	Uses default value set in Oracle8i kernel (no Windows NT-specific value).

Displaying Initialization Parameter Values

Windows NT-specific parameter values can be viewed by using an ASCII editor to open the ORACLE_BASE\ADMIN\DB_NAME\PFILE\INIT.ORA file. To display all parameter values (whether set in the INIT.ORA file or the Oracle8i kernel), enter the following command at the SQL*Plus command prompt:

SQL> SHOW PARAMETER PARAMETER_NAME

where PARAMETER_NAME is the name of a specific initialization parameter.

The value for this parameter, whether defined in the ORACLE_BASE\ADMIN\DB_NAME\PFILE\INIT.ORA file or the Oracle8i kernel, displays on-screen.

Database Initialization Parameters

Check the following initialization parameters when creating a new database. They cannot be modified after you have created the database. See Chapter 6, "Post-Installation Database Creation" for details on creating a new database, including the part of the procedure when you modify these parameters.

Parameter	Description
CHARACTER SET1	Specifies the database National Language Support (NLS) character set to use. This parameter can be set only when you create the database.
DB_BLOCK_SIZE	Specifies the size in bytes of Oracle database blocks.
DB_NAME	Specifies the name of the database to be created. The database name is a string of eight characters or less. You cannot change the name of a database.

1 Not an initialization parameter, but rather a clause in the CREATE DATABASE statement. See Chapter 6, "Post-Installation Database Creation" for an example of using this clause. Calculating Database Limits Use the size guidelines in the following table to calculate Oracle8i database limits using the equations given in the Oracle8i Administrator's Guide.

Type	Size
Maximum block size	16,384 bytes or 16 kilobytes (KB)
Maximum blocks per file	4,194,304 blocks
Maximum possible file size with 16 K sized blocks	64 Gigabytes (GB) (4,194,304 * 16,384) = 64 gigabytes (GB)
Maximum number of files per database (depends on block size):
2 K sized blocks	20,000 files
4 K sized blocks	40,000 files
8 K sized blocks	65,536 files
16 K sized blocks	65,536 files
Maximum file size for a FAT file	4 GB
Maximum file size in NTFS	16 Exabytes (EB)
Maximum database size	65,536 * 64 GB equals approximately 4 Petabytes (PB)
Maximum number of extents per database (depends on block size). Typical values are:
2 KB sized blocks	121 extents
4 KB sized blocks	255 extents
8 KB sized blocks	504 extents
16 KB sized blocks	1032 extents
32 KB sized blocks	2070 extents
Shadow Process Memory:
Release 8.1.6	335 K
Release 8.1.3	265 K
Release 8.0.4	254 K
Release 8.0.5	254 K

See: To calculate the space required by an index, use the equations given in Oracle8i Administrator's Guide.