IBM manual Updating an existing installation, 240 DB2 Deployment Guide

5.5 Updating an existing installation

It is not uncommon that the changes on the database object definitions are required due the application requirements changed. Frequently, the changes are taken place at the test system first then deployed to the production system. The data in the production system sure should be preserved.

To discuss this type of pre-configured database deployment, we define a few terms used in this section:

￿Database configuration:

This is the database layout along with the database objects.

￿Database migration:

Update a database from one configuration to another while preserving its data. In short, “migration” is also used.

￿Current configuration:

This is the configuration of the database in the runtime environment (target environment), thereby, the configuration to be updated.

￿New configuration:

This is the configuration that the current configuration will be changed to. The new configuration is derived from the source system.

We use script, that is DDL and SQL statements, as our basic tool. Using the database backup image is not considered, because the data preservation is a challenging task.

Two major tasks are necessary for migrating a database. The first is to identify the changes between the current configuration and the new configuration and second, apply these changes.

Figure 5-3illustrates the basic idea of how to migrate the database. Our starting point is the ITSODB sample database. We make changes on some of the database objects on the source database ITSODB2 and create a new configuration. Our task is to migrate ITSODB to have this new configuration.

240DB2 Deployment Guide