How to know the specific size of a field in oracle table

Question

Hello,
oracle 11.2.0.3 on redhat
i have three tables with same structure, table0, table50, table100:
create table table0 (id number, shipment RAW(2000), options RAW(2000));
i inserted 10000 rows in each but with some differences:
table0 has 10000 id, but shipment and options has null values
table50 has 10000 id, but shipment and options has only 5000 rows, the other 5000 are null values
table100 has 10000 rows of id, shipment and options. No null values.
I want to know the specific size of each column, also the size of each row, to know the exactly size of the field.
for example:
row 1, column options of table100 has "asdfasdfagasdgasbabsdgoasdpgiahnwe1129u412094u12"
row 2, column options of table100 has "a".
both are raw datatype, but i think its space will has different size (bytes), how to know it? any query?
I found this query:
select owner,tablespace_name,segment_name,sum((bytes/1024/1024)) Bytes
from sys.dba_extents
where owner in 'MAA' and segment_type='TABLE' and segment_name ='TABLE00'
group by tablespace_name,owner,segment_name
order by owner,tablespace_name,segment_name, bytes; but i think it isn't my solution.

Answer 1

thx mr. sb92075
i tried with vsize too but same result:
with table50
SELECT VSIZE(OPTIONS) FROM TABLE00;
VSIZE(OPTIONS)
             1000
             1000
             1000
             1000
               *with table100
SELECT VSIZE(OPTIONS) FROM TABLE100;
VSIZE(C_ELECCION)
             2000
             2000
             2000
             2000
                  *it's the same size for 'a' like 'abcasdfjañldngaosnbaposnbpaosuqroiwejrklasndiaoshbaposdjgajs'?? It's hard for me to believe.
data is saved in blocks, a extents is a contiguos number of blocks and a group of extensions are segments. If you insert some text in a table field, Oracle create a extension and insert there the data but depend the bytes you insert Oracle will create one or more extents. How to know this specific space in that field?