Tailoring for Performance

When building access paths within your model, you should pay attention to certain aspects of system design that will enable you to obtain the best system performance. Some issues regarding access paths could affect the performance of your application. This chapter explains the issues for i OS logical files and relates them to the default values for access paths. Depending on your design, you might want to consider the following topics.

Considering the Types of Data in the Physical File
Minimizing the Number of Active Indexes
Maintaining Access Paths (Immediate, Delay, Rebuild)
Using Select/Omit Criteria
Using Virtual Fields (Join Logical Files)
Multi-format Access Paths
Using Open Data Paths
Creating Default Retrieval Access Paths

For more information about system performance considerations, refer to CA Xtras Performance Expert User Guide and IBM i Database Guide.

This section contains the following topics:

Considering the Types of Data in the Physical File

Minimizing the Number of Active Indexes

Access Path Maintenance (Immediate, Delay, or Rebuild)

Using Select/Omit Maintenance

Using Join Logicals

Using Multi-Format Access Paths

Using Open Data Paths

Creating Default Retrieval Access Paths