ABAP Dictionary
You use the ABAP Dictionary to create and manage data definitions (metadata). The ABAP Dictionary permits a central description of all the data used in the system without redundancies. New or modified information is automatically provided for all the system components. This ensures data integrity, data consistency and data security.
The ABAP Dictionary supports the definition of user-defined types (data elements, structures and table types). You can create the corresponding objects (tables or views) in the underlying relational database using these data definitions. The ABAP Dictionary describes the logical structure of the objects used in application development and shows how they are mapped to the underlying relational database in tables or views.
The ABAP Dictionary also provides standard functions for editing fields on the screen, for example for assigning input help to a screen field.
The ABAP Dictionary is completely integrated in an ABAP system. The ABAP system works interpretatively, permitting the ABAP Dictionary to be actively integrated in the development environment. Instead of the original objects, the interpreters see only internal representations of these objects.
These internal representations are adjusted automatically when the system finds that changes have been made in the ABAP Dictionary. This ensures that the screen and ABAP interpreters, input help, database interface, and development tools always access current data.
When you work on development projects, objects of the ABAP Dictionary can be changed any number of times before being activated and made available to the operative components of the system. Objects can have both an active and an inactive version in the ABAP Dictionary at the same time.
Inactive ABAP Dictionary objects have no effect on the runtime system (ABAP processor, database interface). This permits greater changes to several objects without impairing the executability of the system. The objects can be activated together only when they all have been changed.