Performance Tuning for Content Manager

Chapter 8. Tuning DB2 for Content Manager 177

The following commands (which are discussed in detail later in this chapter) will

configure DB2 to initialize the Library Server’s database processes:

db2 update dbm cfg using NUM_POOLAGENTS <n>

db2 update dbm cfg using NUM_INITAGENTS <n>

db2 update dbm cfg using MAXAGENTS <m>

In these examples:

 <n> is the expected number of concurrent users, and

 <m> is at least twice <n>.

If other databases share this instance, you can increase the MAXAGENTS

parameter to reflect all the total number of agents that are working on all

applications.

8.2.5 Create attribute indexes

The Library Server and the Resource Manager databases are installed with the

appropriate indexes to optimize create, retrieve, update, and delete operations.

When you define a new item type, the appropriate indexes are created

automatically. Indexes on user-defined item attributes are not generated

automatically. For the attributes that are frequently used for regular searches,

creating indexes on these attributes often improves response time and reduces

resource usage for queries using these attributes.

Indexes can negatively affect response times for create, update, and delete

operations for that item type as well as increase the database size and buffer

pool usage. You should monitor overall system performance and response time

before and after adding an index to evaluate its overall value. A part of this

process should be running your SQL through the DB2 Explain function to verify

that the new indexes are being used.

How to create an index

You can use the Content Manager system administration client or the DB2

Control Center to add an index for a single attribute. If you want to create an

index over multiple attributes, then you must create it manually. In order to be

effective, manually created indexes must include certain key system-defined

attributes.