Oracle 12 has introduced the concept of invisible
columns. The idea of invisible columns is similar to
the idea of creating a view on a table while leaving out the
columns that you do not want the end-user to see.
The invisible columns can be controlled by commands.
Used as an argument to the create table and
alter table commands, you can easily create an
invisible column. Note that the dba_tab_cols view also
has a new column named hidden_column:
create table
temp
( a number,
b number invisible,
c number);
Table
created.
SQL> desc
temp
Name
Null? Type
-----------------------------------------------------
-------- ---------------------------
A NUMBER
C NUMBER
select
column_name,
hidden_column,
column_id
from
user_tab_cols
where
table_name='TEMP';
COLUMN_NAM HID COLUMN_ID
---------- --- ----------
A
NO 1
B
YES
C
NO
2
alter table
temp
modify
(b visible;
Table
altered.
SQL>
desc
temp
Name
Null?
Type
-----------------------------------------
-------- ------------------------
A NUMBER
C NUMBER
select
column_name,
hidden_column,
column_id
from
user_tab_cols
where
table_name='TEMP';
COLUMN_NAM HID COLUMN_ID
---------- --- ----------
A
NO
1
B
NO
3
C NO 2
 |
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