CREATE [OR REPLACE] FUNCTION [Function Name] [Parameter List]
RETURN [Data type]
[AUTHID DEFINER | CURRENT_USER]
[DETERMINISTIC | PARALLEL_ENABLED | PIPELINES]
[RESULT_CACHE [RELIES_ON (table name)]]
IS
  [Declaration Statements]
BEGIN
  [Executable Statements]
  RETURN [Value]
EXCEPTION
  [Exception handlers]
END [Function Name];