Database Tuning

This section describes the other tunable parameters available to an Oracle Internet Directory installation.

The following table gives a quick overview of the recommended values of RDBMS parameters for various client loads. These parameters are configurable in the initialization parameter file.

Parameters	500 Concurrent LDAP Clients	1000 Concurrent LDAP Clients	1500 Concurrent LDAP Clients	2000 Concurrent LDAP Clients
Open_cursors	200	200	200	200
Sessions	225	600	800	1200
Database_block_buffers	200 to 250 MB	200 to 250 MB	200 to 250 MB	200 to 250 MB
Database_block_size	8192	8192	8192	8192
Shared_pool_size	30 to 40 MB	30 to 40 MB	30 to 40 MB	30 to 40 MB
Processes	400	800	1000	1500

This section describes each of the RDBMS tunable parameters in more detail. It contains these topics:

• Required Parameter

• Parameters Dependent on Oracle Internet Directory Server Configuration

• SGA Parameters Dependent on Hardware Resources

Required Parameter

Configure the OPEN_CURSORS parameter as follows:

OPEN_CURSORS=200

The Oracle9i default of 50 or so is too small to accommodate Oracle Internet Directory server cursor cache. Note that this value is not dependent on other Oracle Internet Directory server parameters, such as # SERVERS and # WORKERS. The value of 200 is sufficient for any size DIT.

Parameters Dependent on Oracle Internet Directory Server Configuration

Configure the SESSIONS parameter as follows:

PROCESSES = (# OID server processes for each instance) x 

        (# DB Connections for each server + 1) x 
        (# of OID instances) + 20

SESSIONS = 1.1 * PROCESSES + 5

Each Oracle Internet Directory server process requires a number of concurrent database connections equal to the number of worker threads configured for that server plus one. The total number of concurrent database connections allowed must therefore include this number for each server, for each instance. The additional 20 connections added to the parameter value accounts for the Oracle background processes plus other Oracle Internet Directory processes such as OID Monitor, OID Control, Oracle directory replication server, and bulk tools.

Using Shared Server Process

Depending on the total number of concurrent database connections required, and as determined by the setting for the SESSIONS parameter, enabling shared server process may help balance overall system load better. If the total number of concurrent database connections required is over 300, then configure the shared server. One shared server should be configured for every 10 database connections required.

Note: The number of required concurrent database connections depends on the hardware selected. See Oracle9i Net Services Administrator's Guide and Oracle9i Database Administrator's Guide, both in the Oracle Database Documentation Library, for further information about the shared server configuration.

SGA Parameters Dependent on Hardware Resources

The main parameters that contribute to the SGA are discussed in "Memory Tuning". The following are a few more parameters that may be tuned:

• Sort area

  Set to 262144 (256k) to ensure sufficient sort area available to prevent sorts on disk.

• Redo Log Buffers

  Set to 32768 (32k) as an initial estimate. If log write performance becomes a performance problem, use a large enough value to make sure (redo log space requests / redo entries) > 1/5000 to prevent the LGWR process from falling behind. This overall has little size effect on the variable SGA size, so making this a little bit too large should not be a problem.