1. DB functions are specialized procedures having any number of input parameters but just one output parameter. The output parameter is the result of the function, thus also defining the data type of the function's result.
2. In SQL statements, DB functions can be used like predefined functions. DB functions can be used to transfer functionality from the application programming to the ADABAS server. If DB functions are used in search conditions, the size of the result, if any, can be decreased considerably. This reduces both the storage space required by the result and the overhead to transfer the result into the application program.
3. DB functions can be used in all SQLMODEs, except ANSI. They can be nested with predefined functions and DB functions.
4. Names of DB functions should differ from the names of predefined functions in any of the SQLMODEs. If a predefined function is available in an SQLMODE, the predefined function is used, not the DB function.
5. No SQL statements are valid within a DB function.
6. For the programming of DB functions, refer to the manuals of the corresponding ADABAS components.