sql - oracle comments on column of object type table -

i have object type

create or replace type header_o object( col1 number,  col2 number,  col3 number); 

then create table

create table tab1( id number,  header header_o); 

so want make comment on header.col1
when try

comment on column tab1.header.col1 'comment goes here'; 

oracle raises missing keyword.
how can make work?

oracle comments on column of object type table

no, cannot. oracle doesn't support feature.

from documentation, add comments to:

• table, view, or materialized view
• indextype
• operator

while, trying add comment object type. add comments table column.

for example,

sql> create or replace type header_o   2    3    object   4    (   5      col1 number,   6      col2 number,   7      col3 number)   8  /  type created.  sql> create table tab1   2    ( id number, header header_o   3    )   4  /  table created.  sql> comment on column tab1.header 'comment goes here'   2  /  comment created.