SQL> create table t as select object_name from all_objects;


SQL> insert into t select 'SMITH' from t where rownum <= 196;

SQL> select count(*) from t;


COUNT(*)
--------
   17303

SQL> create index t_idx on t(object_name);


SQL> analyze table t compute statistics;

SQL> set autotrace traceonly explain;

SQL> select * from t where object_name = 'SMITH';


Execution Plan
----------------------------------------------------------------------   
0   SELECT STATEMENT Optimizer=CHOOSE (Cost=1 Card=2 Bytes=48)
    1    0   INDEX (RANGE SCAN) OF 'T_IDX' (NON-UNIQUE) (Cost=1 Card=2 Bytes=48)