l to h

    A compression clause for all-numeric columns that translates the
    column values into a compact, encoded form. You can mix mapped
    and unmapped columns, but the most storage space is gained by
    building indexes of multiple columns of data type SMALLINT or
    INTEGER. Oracle Rdb attempts to compress all such columns into
    the smallest possible space.

    The l (low) through h (high) specifies the range of integers as
    the value of the index key.

    The Oracle Rdb SQL Reference Manual describes addiional
    restrictions about this argument.