Block Space Calculation - note 10640.1

 Hello,

I use the note 10640.1, Extent and Block Space Calculation and Usage in Oracle Databases.  My database is 9.2.0.8.

Using the results from above, we can calculate the total average row size (or
the minimum amount of space required by a row) in a non-clustered table with 
the formula:

   average row size = row header + F + V + D (bytes per row)  

      where:
         row header = 3 bytes per row of a non-clustered table

         F          = total length bytes of all columns with 1 byte column 
                      lengths (CHAR, NUMBER, DATE, and ROWID types)

         V          = total length bytes of all columns with 3 byte column 
                      lengths (VARCHAR2, LONG, RAW, LONG RAW datatypes)