Finding size of a ito

create table iot (a primary key, owner) organization index as
select object_id, owner from dba_objects where object_id is not null and rownum < 11

Table created.

explain plan for select * from iot;

Explained.

@utlxpls


PLAN_TABLE_OUTPUT
-------------------------------------------------------------------------------------------
Plan hash value: 12198353

-------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
-------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 10 | 300 | 2 (0)| 00:00:01 |
| 1 | INDEX FAST FULL SCAN| SYS_IOT_TOP_128290 | 10 | 300 | 2 (0)| 00:00:01 |
-------------------------------------------------------------------------------------------



Notice it only read SYS_OIT_TOP_128290 object.


select owner, index_name, index_type from dba_indexes where table_name ='IOT';

OWNER INDEX_NAME INDEX_TYPE
------------------------------ ------------------------------ ---------------------------
SYS SYS_IOT_TOP_128290 IOT - TOP

select index_name, column_name from dba_ind_columns where index_name = 'SYS_IOT_TOP_128290';

INDEX_NAME COLUMN_NAME
------------------------------ ------------------------------
SYS_IOT_TOP_128290 A


Where is the column owner?

When i issue a query on my iot, it only access the object SYS_IOT_TOP_128290.
When i query SYS_IOT_TOP_128290, in dba_ind_columns, only column a show up. Not owner.

Where does the column owner is stored?

Its in DBA_TABLES, ALL_IND_COLUMNS

Columns do not have an owner, objects do.

Follows layout of the view you are quering...

Code:

---

SQL> desc dba_ind_columns
 Name                                      Null?    Type
 ----------------------------------------- -------- ------------------
 INDEX_OWNER                              NOT NULL VARCHAR2(30)
 INDEX_NAME                                NOT NULL VARCHAR2(30)
 TABLE_OWNER                              NOT NULL VARCHAR2(30)
 TABLE_NAME                                NOT NULL VARCHAR2(30)
 COLUMN_NAME                                        VARCHAR2(4000)
 COLUMN_POSITION                          NOT NULL NUMBER
 COLUMN_LENGTH                            NOT NULL NUMBER
 DESCEND                                            VARCHAR2(4)

---

Did not got u. As PAVB said, columns does not have an owner. They belongs to a table and the table has owner.

The plan on the other hand seems completely OK