Changing an External Database Schema

Use the External Schema Wizard to maintain an existing external database schema selected in the External Databases Browser. If the definition of the external relational database changes, the transformed (external database schema) definition that is stored in the JADE database may be incomplete or wrong.

To ensure that the external relational database and your external database schema retain concurrency, JADE performs the following actions.

1. Stores a complete description of the parts of the original external schema that are transformed, to allow comparison against any later version of the same schema.

2. Detects differences when establishing a connection to an external database and prevents access at a table level when such differences are detected.

3. Enables you to update the transformed (external database schema) definition, including the removal of obsolete elements. This process indicates new, out-of-date, or deleted elements.

To change an external database definition

1. Select the external database schema in the External Databases Browser.

2. Select the Change command from the Databases menu.

When you change an existing external database schema, the Name text box in the first sheet of the External Schema Wizard displays the name of your external database schema. As you cannot change the name of an existing external database schema, this text box is disabled.

The External Schema Wizard is then displayed. For details about using the External Schema Wizard, see "Adding an External Database Schema", earlier in this chapter.