When blank-padded comparison semantics is used, if the two values have
different lengths, Oracle first adds blanks to the end of the shorter one
so their lengths are equal. Oracle then compares the values character
by character up to the first character that differs. The value with the
greater character in the first differing position is considered greater. If
two values have no differing characters, then they are considered equal.
This rule means that two values are equal if they differ only in the number
of trailing blanks. Oracle uses blank-padded comparison semantics only
when both values in the comparison are either expressions of data type
char, text literals, or values returned by the user-defined function.