Chapter 10. The Database Reorganization Process

This chapter provides an overview of the database reorganization tasks that an IMS Database Administrator performs.

Specifically, this chapter:

• Introduces the requirements for and the process of IMS database reorganization.

• Describes the available IMS utilities for reorganizing HD databases.

• Describes how to use the utilities for particular situations, including which utility must be run to reorganize an HD database with and without logical relationships or secondary indexes.

• Includes a short discussion about initially loading databases with logical relationships and secondary indexes, because doing so also requires the reorganization utilities to build the logical relationships and secondary indexes.

• Discusses reorganizing HALDBs, which have a simpler and shortened reorganization process than do the other full-function databases. As of IMS Version 9, you can reorganize HALDB databases without taking them offline.

Related Reading:

• For more information about reorganizing HALDBs, see "Reorganizing HALDBs" on page 128.

• For a complete discussion on the topic of database reorganization, see IMS Version 9: Administration Guide: Database Manager.

In This Chapter:

• "Purpose of Database Reorganization"

• "When to Reorganize Databases"

• "Overview of the Database Reorganization Process" on page 128