Data base functions are a type of [stored procedure] that returns a value to a calling program.  

The function may take parameters or not, but will generally perform a computation or a data retrieval to determine a value and will then return that value to the calling program.

At its simplest, an Oracle function like [SYSDATE] returns to the calling program, the current date/time.  

A moderately more complex function is the [P2K_SMGLX] function which takes two parameters, and executes a data base retrieval to determine the descriptive value of a [lexicon].

A more complex function is [P2K_SEGR] which takes a number of parameters, some of which are optional, and will retrieve data and perform computations to determine a wage in a variety of [rate basis] values.

See the list of [Callable Functions] that can be used by interfaces and discoverer.