SQL> CREATE TABLE ttt (col1 varchar2(100));

TABLE created.

SQL> CREATE INDEX ttt_idx ON ttt(col1);

INDEX created.

SQL> INSERT INTO ttt VALUES('one');

1 ROW created.

SQL> SET autotrace traceonly
SQL> SELECT * FROM ttt;


Execution Plan
----------------------------------------------------------
Plan hash VALUE: 774701505

--------------------------------------------------------------------------
| Id  | Operation         | Name | ROWS  | Bytes | Cost (%CPU)| TIME     |
--------------------------------------------------------------------------
|   0 | SELECT STATEMENT  |      |     1 |    52 |     2   (0)| 00:00:01 |
|   1 |  TABLE ACCESS FULL| TTT  |     1 |    52 |     2   (0)| 00:00:01 |
--------------------------------------------------------------------------

Note
-----
   - dynamic sampling used FOR this statement (level=2)


Statistics
----------------------------------------------------------
          5  recursive calls
          0  db block gets
          8  consistent gets
          0  physical reads
          0  redo SIZE
        527  bytes sent via SQL*Net TO client
        523  bytes received via SQL*Net FROM client
          2  SQL*Net roundtrips TO/FROM client
          0  sorts (memory)
          0  sorts (disk)
          1  ROWS processed