Table indexes

COLUMN index_name          FORMAT A40                HEADING "Index Name"
COLUMN column_name         FORMAT A30                HEADING "Column Name"
COLUMN column_length                                 HEADING "Column Length"

BREAK ON index_name SKIP 1

SELECT 
    index_owner || '.' || index_name  index_name
  , column_name
  , column_length
FROM
    dba_ind_columns
WHERE
      table_owner  = UPPER('&sch')
  AND table_name   = UPPER('&tab')
ORDER BY
    index_name
  , column_position
/