A data dictionary in computing terms is the source of information in which the system data is defined in a logical way. The data dictionary is the centralized and structured source of information for business applications.
The ABAP data dictionary (DDIC) can be seen as a logical representation or a superior layer over the physical underlying database.
The elements that make up a DDIC are known as metadata. Metadata is the computing term for the data whose function is to describe other data.
An advantage of having a DDIC is avoiding inconsistencies when defining data types that will later be used in different parts of an application; this avoids redundancies and considerably decreases the cost of maintenance.
When a type of data is defined in DDIC, it is available to any program or function module in the application. A change in the definition of a type of data in the DDIC automatically affects any other data, module, function, or program which has data or variables defined using the modified data type.
The ABAP DDIC is the core of the R/3 development system. It is the source of every definition within R/3, from the very basic domains to the company model. It is totally integrated with the other tools of the development environment.
Transaction code SE11 for Data Dictionary and SE16 for Data Browser.
Data Dictionary Objects
- Database Tables
- Data Elements
- Table Types
- Type Groups
- Search Helps
- Lock Objects