(1) A relationship between a set of input data values and a set of result values that is used to extend and customize SQL or XQuery. Functions are invoked from elements of SQL statements such as the select list or the FROM clause and from XQuery as primary expressions. See also aggregate function, built-in function, external function, scalar function, sourced function, table function, user-defined function, SQL function, row function, routine.
(2) Any instruction or set of related instructions that perform a specific operation.
(3) A named group of statements that can be called and evaluated and can return a value to the calling statement. See also built-in function.
(4) In REXX, a series of instructions that a REXX procedure calls to perform a specific task and to return a value. The three types of routines that can be called as functions are internal, built-in, and external.
(5) In SQL, an operation that supplies a single value from another value or from a set of values. A function obtains a single value by applying the function name (for example, AVG) to the result of the expression (for example, column-name).
(6) A machine action such as carriage return or line feed.
(7) In ADSI, an ADSI instruction, or group of instructions.