The following query returns the result ' RIGHTT TRIM': the trailing spaces are removed, but the leading spaces are not removed.
Since the expr2 argument is not explicitly specified in the query, the default of a single space is used.
RTRIM removes spaces from the right side of expr1 argument, and it stops removing characters when it encounters 'M' because 'M' is not in the expr2 argument.
SELECT RTRIM(' RIGHTT TRIM ');