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Guidelines for Configuring Settings in the init.ora File

The init.ora file contains parameters that have a major effect on the performance of Siebel Business Applications using Oracle Database.

Use the following settings as guidelines for your initial configuration. Your final settings will vary depending on the hardware configuration, the number of users, and the type of workload.

In the init.ora file, default parameter values are provided for small, medium, and large database deployments. Unless the configuration parameters are specified in the following settings, set them to the large database values. For detailed descriptions of each of the parameters and their effects on database performance and system resource utilization, see Oracle Database documentation.

This topic is part of Configuring an Oracle Database for Siebel Business Applications.

Brief descriptions follow for several parameters for which you might have to adjust values:

• CURSOR_SHARING. This parameter is set to EXACT by default and must not be changed.

  CAUTION:  Changing this value might lead to failure of some Siebel Server components.

• DB_FILE_MULTIBLOCK_READ_COUNT. The database buffer cache parameter dictates the number of data blocks that are read in a single Oracle I/O operation during a table scan. For most implementations, set this parameter to an initial value of 32. If you are using NAS storage (such as a NetApp Filer), then set the value to 8 to reduce potential network traffic problems.
• MEMORY_TARGET. This parameter specifies the Oracle system-wide usable memory. A common recommendation is to set it to a value equalling the physical memory minus 1 GB. For example, if the Oracle Database server has 16 GB of memory, then set MEMORY_TARGET to 15 GB.
• NLS_DATE_FORMAT. Set this parameter as needed. The default setting is DD-MON-YY. For information about the supported formats, see Oracle Database documentation and see Specifying the Locale for Siebel Business Applications.
• NLS_SORT. The sort order is specified during the initial installation of a database and defines the way in which the database sorts character data. Sort order support depends on both the code page of the database and whether it will be used in a development or a production environment. For more information, see Specifying the Locale for Siebel Business Applications.

  Considerations for development and production environments are as follows:

  • Development environment databases. The repository object names in your development environment database must sort using a binary sort order, because Siebel Tools uses this sort order internally. Specify the same sort order at the database client level, so that output there does not have to be resorted.

    NOTE:  Binary sort order is the simplest and fastest sort order to perform in the database. Binary sorting is case-sensitive and is based on the numeric values (for example, 0 through 255 for an 8-bit character set) of the characters in the installed character set.

    Customers are responsible for making sure their data is backed up and restored correctly.

  • Production environment databases. For information about production environment database restrictions, see the Certifications tab on My Oracle Support. See also Oracle Database documentation.
• OPEN_CURSORS. This parameter controls the amount of spaces that are reserved for the maximum number of cursors (a cursor being the same as an open query). The minimum open cursor requirement for Oracle Database is 1000 and the maximum is 2000. Within these limits, this parameter can be adjusted according to observed usage patterns.
• OPTIMIZER_FEATURES_ENABLE. This is an umbrella parameter for enabling a series of optimizer features that are based on an Oracle release number. For example, set this parameter to a value corresponding to the current release level of your Oracle Database. For more information, see Oracle Database documentation. For more information about performance tuning for Siebel CRM with an Oracle Database, see 781927.1 (Article ID) on My Oracle Support.
• OPTIMIZER_INDEX_COST_ADJ. It is recommended that you set this parameter to 1. Use this parameter to tune the optimizer to use index access path over a full table scan. However, depending on the data shape for your Siebel database, how statistics are gathered, and the nature of your Siebel configuration changes, other values might provide better results.
• OPTIMIZER_MODE. Set this parameter to ALL_ROWS (the default) for the Cost-Based Optimizer (CBO).

  NOTE:  For more information about performance tuning for Siebel CRM with an Oracle Database, see 781927.1 (Article ID) on My Oracle Support. See also Siebel Database Upgrade Guide.