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Setting Database Initialization Parameters

Table: Initial Settings for Database Parameters identifies the parameters that affect the performance of Oracle OLAP. Alter your server parameter file or init.ora file to these values, then restart your database instance. You can monitor the effectiveness of these settings and adjust them as necessary.

To set the system parameters: 

  1. Open the init.ora initialization file in a text editor.

  2. Add or change the settings in the file, as described in Table: Initial Settings for Database Parameters.

  3. Stop and restart the database.

    On Windows, use the Services utility to stop and restart OracleService.

    On Linux, use commands like the following. Be sure to identify the initialization file in the STARTUP command.

    SQLPLUS '/ AS SYSDBA'
    SHUTDOWN IMMEDIATE
    STARTUP pfile=$ORACLE_BASE/admin/orcl/pfile/init.ora.724200516420
    

See Also:


Initial Settings for Database Parameters

Parameter Default Value Recommended Setting Description

JOB_QUEUE_PROCESSES

1000

If you reduce this value to limit the maximum number of job slaves running on an instance, then calculate the following number of processes for use by OLAP:

Number of CPUs, plus one additional process for every three CPUs; in a multi-core CPU, each core counts as a CPU

For example, JOB_QUEUE_PROCESSES=5 for a four-processor computer

Controls the degree of parallelism in OLAP builds, as described in "Parallelism"

PARALLEL_DEGREE_POLICY

MANUAL

AUTO or LIMITED

Controls how the degree of parallelism is determined

When set to AUTO or LIMITED, Oracle determines whether a SQL statement executes in parallel and, if so, the degree of parallelism used

SESSIONS

Derived

2.5 * maximum number of simultaneous OLAP users

Provides sufficient background processes for each user

UNDO_MANAGEMENT

AUTO

(MANUAL in 10g)

AUTO

Specifies use of an undo tablespace

UNDO_TABLESPACE

Derived

Name of the undo tablespace, which must be defined previously

Identifies the undo tablespace defined for OLAP use, as shown in "Creating an Undo Tablespace for OLAP".