Oracle Relation Query - DBA_CONSTRAINTS

Ref. http://www.shutdownabort.com/dbaqueries/Structure_Constraints.php
Ref. http://docs.oracle.com/cd/B19306_01/server.102/b14237/statviews_1037.htm

-- View The Relation of The Specific Table

col type format a10
col cons_name format a30
select decode(constraint_type,
  'C', 'Check',
  'O', 'R/O View',
  'P', 'Primary',
  'R', 'Foreign',
  'U', 'Unique',
  'V', 'Check view') type
, constraint_name cons_name
, status
, last_change
, R_CONSTRAINT_NAME
, RELY
from dba_constraints
where owner like '&owner'
and table_name like '&table_name'
order by 1
/

-- View The PK column of The Specific Table

SELECT cols.table_name, cols.column_name, cols.position, cons.status, cons.owner
FROM all_constraints cons, all_cons_columns cols
WHERE cols.table_name = '&table_name'
AND cons.constraint_type = 'P'
AND cons.constraint_name = cols.constraint_name
AND cons.owner = cols.owner
AND cons.owner ='&owner'
ORDER BY cols.table_name, cols.position;