Index Oracle PLSQL

SQL>
SQL>
SQL> set echo on
SQL>
SQL> create table t as
  2  select * from all_objects;
Table created.
SQL>
SQL> create index t_idx1 on t(object_name);
Index created.
SQL>
SQL> create index t_idx2 on t(object_type);
Index created.
SQL>
SQL> set autotrace traceonly
SQL> select * from t t1 where object_type in( 'FUNCTION','PROCEDURE', 'TRIGGER' );
520 rows selected.
Execution Plan
--------------------------------------------------
Plan hash value: 831817202
--------------------------------------------------
-------------------------------------
| Id  | Operation                    | Name   | Ro
ws  | Bytes | Cost (%CPU)| Time     |
--------------------------------------------------
-------------------------------------
|   0 | SELECT STATEMENT             |        |
596 | 76288 |     7   (0)| 00:00:01 |
|   1 |  INLIST ITERATOR             |        |
    |       |            |          |
|   2 |   TABLE ACCESS BY INDEX ROWID| T      |
596 | 76288 |     7   (0)| 00:00:01 |
|*  3 |    INDEX RANGE SCAN          | T_IDX2 |
 52 |       |     3   (0)| 00:00:01 |
--------------------------------------------------
-------------------------------------
Predicate Information (identified by operation id)
:
--------------------------------------------------
-
   3 - access("OBJECT_TYPE"='FUNCTION' OR "OBJECT_
TYPE"='PROCEDURE' OR
              "OBJECT_TYPE"='TRIGGER')
Note
-----
   - dynamic sampling used for this statement
Statistics
--------------------------------------------------
        248  recursive calls
          0  db block gets
        243  consistent gets
          3  physical reads
          0  redo size
      28155  bytes sent via SQL*Net to client
        754  bytes received via SQL*Net from clien
t
         36  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
        520  rows processed
SQL>
SQL> set autotrace off
SQL>
SQL> drop table t;
Table dropped.
SQL>
SQL> --