What Is the Process for Implementing Database Modifications?

This section describes the procedure required to build the data dictionary and reorganize the database, after you create or modify product lines. You can use this procedure with a single product line or a product line with multiple data areas and data IDs, depending on the options you specify during the process.

Multiple data area reorganizations can occur simultaneously, as long as the product line dictionary is up-to-date. There are two options for building and reorganizing the dictionary for a product line with multiple data areas:

  • Full Product Line Dictionary Build and Reorganization

    When you make structural changes to the product line, such as adding a system code, you must do a full dictionary build and reorganization for the product line and all associated data areas and data IDs.

    When multiple data areas exist, blddbdict creates or rebuilds the structure dictionary first, then the data area dictionaries. If all dictionaries generate without error, they are moved to the appropriate files.

  • Data Area or Data ID Dictionary Build and Reorganization

    When you make changes to data area information, such as file size or location, to one or more data areas, you must do a data area/data ID build and reorganization of the specific data area/data ID dictionaries.

Process flow: Full dictionary and data area/data ID dictionary builds

The following steps describe the procedures shown in the preceding figure.

Implement database modifications

  1. Create or modify the database definition using dbdef.

    At this point, you can make the following changes:

    • add new fields

    • change the definition of existing fields

    • delete unused fields

    • add new files

    • add new system codes

    • assign a database space to the data area or product line

  2. Build the data dictionary.
  3. Create and verify a list of database changes.
  4. Reorganize the database to implement the changes.

    The dbreorg process rebuilds only the tables for which the structure has changed.

  5. Verify successful reorganization.
  6. If you have added or removed fields from the database, modify the associated application programs and recompile the product line.