Get Table/View/Index Definition and Indexed Columns

1. Get View Definition

SQL> SELECT test 
SQL> FROM dba_views
SQL> WHERE owner='' AND view_name='';

2. Get Table Definition

SQL> SET PAGESIZE 0
SQL> SET LONG 100000
SQL> EXEC DBMS_METADATA.SET_TRANSFORM_PARAM(DBMS_METADATA.SESSION_TRANSFORM, 'SQLTERMINATOR', true);
SQL> SELECT DBMS_METADATA.GET_DDL('TABLE','','') FROM dual;

3. Get Index Definition

SQL> SET PAGESIZE 0
SQL> SET LONG 100000
SQL> SELECT DBMS_METADATA.GET_DDL('INDEX','','') FROM dual;

If you are only interested in the indexed column names, simply query COLUMN_NAME of table DBA_IND_COLUMNS.

SQL> SELECT column_name
SQL> FROM dba_ind_columns
SQL> WHERE index_owner='' AND index_name='';