Identifies a compiled Oracle Rdb request. RDML generates request
    handles for statements that contain record selection expressions.
    In almost all cases, it is unnecessary for you to explicitly
    specify request handles.

    You can use a request handle in the following RDML statements:

    o  GET

    o  FOR

    o  START_STREAM

    o  STORE

    o  Statistical Functions (AVERAGE, COUNT, MAX, MIN, TOTAL)