6
Configuring the Server Parameter File in Real Application Clusters Environments

This chapter describes server parameter file placement and configuration in Real Application Clusters environments. The topics in this chapter are:

• Parameter Files and Real Application Clusters

• Using The Server Parameter File in Real Application Clusters

• Parameter File Search Order

• Migrating to the Server Parameter File in Real Application Clusters Environments

• Server Parameter File Errors

• Backing Up the Server Parameter File

  See Also: Oracle9i Real Application Clusters Administration for more information on parameters in Real Application Clusters environments and Oracle9i Real Application Clusters Deployment and Performance for a discussion of parallel execution-related parameters in Real Application Clusters data warehousing environments

Parameter Files and Real Application Clusters

Oracle uses parameter settings in parameter files to determine how to control various database resources. You can use two types of files for parameter administration: the server parameter file or one or more traditional client-side parameter files.

Oracle Corporation recommends that you administer parameters using the server parameter file. If you use the traditional client-side parameter files, parameter changes that Oracle makes as a result of self-tuning are not preserved after shutdown.

Using The Server Parameter File in Real Application Clusters

By default, Oracle creates the server parameter file based on one SPFILE. You can only change parameter settings in the server parameter file using Oracle Enterprise Manager or ALTER SYSTEM SET SQL statements; the server parameter file is a binary file that you cannot directly edit.

If you are migrating from a previous Oracle release, create and configure the server parameter file for Real Application Clusters using the procedures described in the following section.

Location of The Server Parameter File

The default location of the server parameter file when the database creates it from PFILEs is platform-dependent.

The default location of the server parameter file on UNIX is:

$ORACLE_HOME/dbs/spfile$ORACLE_sid.ora 

The default location of the server parameter file on Windows NT and Windows 2000 is:

%ORACLE_HOME%\database\SPFILE%ORACLE_sid%.ORA 

The default location of the server parameters file is inappropriate for Real Application Clusters databases because all instances must use the same server parameter file.

Instead, for UNIX platforms Oracle Corporation recommends that you use a PFILE in:

$ORACLE_HOME/dbs/initsid.ora

For Windows NT and Windows 2000 platforms Oracle Corporation recommends that you use a PFILE in:

%ORACLE_HOME%\database\initsid.ora

This file is for each instance and it references a single, shared initialization parameter file. The file must contain the entry:

SPFILE='/dev/vx/rdsk/oracle_dg/db_spfile'

However, if your platform supports a cluster file system, use an alternate file location of:

SPFILE= $ORACLE_HOME/dbs/spfile.ora

You must use the correct location so that all instances use the same the server parameter file at startup.

To use the DBCA to create your database and to use the server parameter file, on the Initialization Parameters page, select the Create server parameter file (spfile) box under the File Locations tab and enter the raw device path name in the Persistent Parameters Filename field as shown in Figure 6-1.

Figure 6-1 File Locations Tab For Initialization Parameters

Parameter File Search Order

Oracle searches for your initialization parameter file, on UNIX platforms for example, by examining directories in the following order:

1. $ORACLE_HOME/dbs/spfilesid.ora

2. $ORACLE_HOME/dbs/spfile.ora

3. $ORACLE_HOME/dbs/initsid.ora

The search order on Windows NT and Windows 2000 is:

1. %ORACLE_HOME%\database\spfilesid.ora

2. %ORACLE_HOME%\database\spfile.ora

3. %ORACLE_HOME%\database\initsid.ora

Migrating to the Server Parameter File in Real Application Clusters Environments

If you migrate to the server parameter file, create and edit the server parameter file using the procedures described in this section.

Server Parameter File Placement in Real Application Clusters

Put the server parameter file on a raw device that is at least 5MB in size. For single-node multi-instance configurations, or if you are using a cluster file system, you can place the server parameter file on a file system.

Procedures for Migrating to the Server Parameter File

Migrate to the server parameter file by completing the following procedures:

1. Combine the initialization parameter files for all instances into a single initdbname.ORA file by copying all shared IFILE contents as is. All the parameters defined in your IFILE parameter files are global. Therefore, create them as "parameter=value" without sid prefixes.

2. Copy all instance-specific parameter definitions from INITsid.ORA files using the following syntax where sid is the sid of the instance:

   sid.parameter=value 
   
   

3. Create the server parameter file using the CREATE SPFILE statement. For example:

   CREATE SPFILE='/dev/vx/rdsk/oracle_dg/db_spfile' 
   FROM PFILE='?/dbs/init.ora'
   
   

   This statement reads your combined initdbname.ORA file that you created by merging your IFILEs and transfers the settings for parameters from the merged file into your the server parameter file.

   
   

STARTUP PFILE=$ORACLE_HOME/dbs/initsid.ora

SPFILE='/dev/vx/rdsk/oracle_dg/db_spfile'

CREATE PFILE='?/dbs/initdbname.ora'
FROM SPFILE='/dev/vx/rdsk/oracle_dg/db_spfile'