What a simply question - stupid!
What a puzzle it is!
As the result of the function length I performed using the database Oracle 10g installed on my machine, it is 9.
Which one is the correct answer?
Ref:
7: http://www.psoug.org/reference/datatypes.html
8: http://wiki.answers.com/Q/How_many_bytes_does_date_datatype_occupy_in_oracle_9i