Oracle ODI 12c performance tuning how to add hint

In Oracle Data Integrator 12c I have a job that's selecting from quite few number of tables and writing to a file. As suggested by DBA he wanted me to add HINT at the begining of the select query ex:

SELECT
   a.fname,
   a.lname,
   l.abc
FROM
   customers  a,
   location   l,
   region     r
WHERE
 a.xyz =l.xyz and
     l.coloumn = r.coloumn and
       a.id = 1243
   AND b.city = 'new york' .... 

the above needs to be changed to

SELECT
    /*+ leading (a) */ a.fname,
    a.lname,
    l.abc
FROM
    customers  a,
    location   l,
    region     r
WHERE
      a.xyz =l.xyz and
      l.coloumn = r.coloumn and 
        a.id = 1243
    AND b.city = 'new york'....

how to achieve this in ODI and where can I observer the change.

Thank you all