Question on Oracle rowid column in every table
I found the answer of my own question. The so called object number from DBMS_ROWID.Rowid_object corresponds to dba_objects.data_object_id, not object_id.

sys@ORCL&gt;select owner, object_name, object_id, data_object_id from dba_objects where data_object_id = 73321;

OWNER    OBJECT_NAME OBJECT_ID  DATA_OBJECT_ID
-------- ----------- ---------- --------------
HR       EMPLOYEES   73953      73321

sys@ORCL&gt;