Performance Tuning for Content Manager

Chapter 8. Tuning DB2 for Content Manager 209

Our recommendation

The Content Manager installation program changes this value to 200 for the

Library Server database, and to 512 for the Resource Manager database.

Change these values depending on your environment, based on how many

concurrent users you have.

Increasing the value of this parameter without lowering the MAXLOCKS

parameter or increasing the LOCKLIST parameter could cause you to reach the

database limit on locks (LOCKLIST) rather than the application limit and as a

result cause pervasive lock escalation problems.

Keep in mind that an application can connect to the database only if there is an

available connection (MAXAPPLS) as well as an available agent (MAXAGENTS).

In addition, the maximum number of applications is also controlled by the

MAX_COORDAGENTS configuration parameter, because no new applications

(that is, coordinator agents) can be started if MAX_COORDAGENTS has been

reached.

8.6.4 Average number of active applications (AVG_APPLS)

Impact

DB - Low

Description

This parameter specifies the average number of active applications. It is used by

the SQL optimizer to help estimate how much buffer pool will be available at run

time for each application. With a value of 1, for example, the optimizer assumes

that the entire buffer pool will be available to one application.

Default values (range)

1 (1 - MAXAPPLS)

To update

Run the following DB2 command:

db2 update db cfg for <database name> using AVG_APPLS <parameter value>

Our recommendation

The Content Manager installation program changes this value to 5 for the Library

Server database, which should be sufficient.

When running DB2 in a multi-user environment, particularly with complex queries

and a large buffer pool, you might want the SQL optimizer to know that multiple