SCOTT@orcl_11g> CREATE TABLE users
  2    (name_col  VARCHAR2 (30))
  3  /

Table created.

SCOTT@orcl_11g> INSERT ALL
  2  INTO users (name_col) VALUES ('ahm')
  3  INTO users (name_col) VALUES ('ahmm')
  4  INTO users (name_col) VALUES ('ahm ahm ahm')
  5  SELECT * FROM DUAL
  6  /

3 rows created.

SCOTT@orcl_11g> INSERT INTO users (name_col)
  2  SELECT object_name
  3  FROM   user_objects
  4  /

606 rows created.

SCOTT@orcl_11g> CREATE INDEX users_name_col_idx
  2  ON users (name_col)
  3  INDEXTYPE IS CTXSYS.CONTEXT
  4  /

Index created.

SCOTT@orcl_11g> select score(1), Name_Col
  2  from   Users
  3  where  contains (Name_Col, '?ahm',1) > 0
  4  order  by score(1) DESC
  5  /

  SCORE(1) NAME_COL
---------- ------------------------------
        31 ahm ahm ahm
        10 ahm
        10 ahmm

SCOTT@orcl_11g>