Data Independence

This section describes how you can change the database without recompiling the programs that access the database.

If the structure of a table is changed in a way that does not affect the indexing, then the data independence mechanism allows records with the old and new structure to co-exist on the database. The application program 'sees' the old or new structure of the database as appropriate.

This section is divided into the following topics:

• Use of Generation Numbers

• Preserving Data Independence

• Data Type Conversion