The New Oracle8 ROWID format

The Oracle8.0 "new features" courses talk about the file number
component of the ROWID as being the relative data file number within the
tablespace. (In Oracle7 the datafile component of ROWID is the absolute
data file number within the database.)

I cannot produce an example that shows the difference. My attempt below
shows a partitioned table with two partitions containing two rows, one
in each partition, with each partition being in a different tablespace.
When I compare the relative data file numbers with the absolute data
file numbers I do not see any difference. I would have expected the
relative file number to be, say, 1 (meaning first data file within
tablespace).

Can anyone give me an example which would show the difference.

Test is on 8.0.4.

CREATE TABLE junk (ord_id NUMBER)
   PARTITION BY RANGE (ord_id)
   (PARTITION p1 VALUES LESS THAN (10)       TABLESPACE data01,
    PARTITION p2 VALUES LESS THAN (MAXVALUE) TABLESPACE data02);
INSERT INTO junk VALUES (1);
INSERT INTO junk VALUES (11);
COMMIT;

SELECT RPAD(o.object_name,10) object,
       o.object_id,
       p.tablespace_name tablespace
  FROM user_objects o, user_tables p
 WHERE o.object_type = 'TABLE'
   AND o.object_name = 'JUNK'
   AND o.object_name = p.table_name
 UNION
SELECT RPAD(o.object_name||'.'||o.subobject_name,10) object,
       o.object_id,
       p.tablespace_name tablespace
  FROM user_objects o, user_tab_partitions p
 WHERE o.object_type = 'TABLE PARTITION'
   AND o.object_name = 'JUNK'
   AND o.object_name = p.table_name
   AND o.subobject_name = p.partition_name;

SELECT DBMS_ROWID.ROWID_OBJECT(ROWID) object,
       DBMS_ROWID.ROWID_RELATIVE_FNO(ROWID) relative_fno,
       DBMS_ROWID.ROWID_TO_ABSOLUTE_FNO(ROWID,user,'JUNK') absolute_fno,
       DBMS_ROWID.ROWID_BLOCK_NUMBER(ROWID) block_number,
       ord_id
  FROM junk;
 

Output is

OBJECT      OBJECT_ID TABLESPACE
---------- ---------- ------------------------------
JUNK             3474
JUNK.P1          3475 DATA01
JUNK.P2          3476 DATA02

    OBJECT RELATIVE_FNO ABSOLUTE_FNO BLOCK_NUMBER     ORD_ID
---------- ------------ ------------ ------------ ----------
      3475            5            5            3          1
      3476            7            7            3         11
 

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Before you buy.

Answer:

you would have to create a database with lots (thousands) of files.
The relative file number will be a 2 byte integer.  The absolute file
name is a 4 byte integer in 8.  The relative will equal the absolute
until you get a whole mess of files in there.  The relative file number
is by tablespace and was kept a short integer to avoid have to change
the internal format of a rowid.