Hint clause in XC?

I came to this idea.   This could be a wicked idea though.   In the future, we will see many statement which we cannot generate the best plan.   So, to do this, we may need to accept a hint which distribution to rely on, as

SELECT * FROM A,B,C WHERE A.A=B.B and B.B=C.C A.A in (SELECT Z from X WHERE Y=100) /*+ USE_PUSHDOWN TO ALL */

Looks tempting ....