Oracle SQL: show table columns, their data types and primary key positions

select
   case when nvl(lag(tabc.owner || '.' || tabc.table_name) over (order by tabc.owner, tabc.table_name, tabc.column_id), 'n/a') <> tabc.owner || '.' || tabc.table_name then tabc.owner      end owner,
   case when nvl(lag(tabc.owner || '.' || tabc.table_name) over (order by tabc.owner, tabc.table_name, tabc.column_id), 'n/a') <> tabc.owner || '.' || tabc.table_name then tabc.table_name end table_name,
   tabc.column_name,
   tabc.data_type,
   tabc.data_length,
   tabc.data_precision,
   tabc.data_scale,
   tabc.nullable,
   pkcl.position           primary_key_position
from
   dba_tab_columns     tabc                                                     left join
   dba_constraints     conp  on tabc.table_name      = conp.table_name      and
                                tabc.owner           = conp.owner           and
                                conp.constraint_type = 'P'                      left join
   dba_cons_columns    pkcl  on conp.constraint_name = pkcl.constraint_name and
                                conp.owner           = pkcl.owner           and
                                tabc.column_name     = pkcl.column_name
order by
   tabc.owner,
   tabc.table_name,
   tabc.column_id
;