>>>Yeah I spotted that ;-)
>>>
>>>Thanks for both of your responses, however I'm getting the same results :-(
>>
>>Can you post SYS(3054,11) output?
>
>Rushmore optimization level for table p: none
>Rushmore optimization level for table rr: none
>Rushmore optimization level for intermediate result: none
>Joining intermediate result and table rr using index tag Referra5
>Rushmore optimization level for table p: none
>Rushmore optimization level for table r: none
>Rushmore optimization level for intermediate result: none
>Joining intermediate result and table p using index tag Client1
>Joining intermediate result and table r using index tag Referra5
>
>>How many records are in each table?
>
>Person = 19650
>Referral = 52186
>
>>Is query optimizable if you run it w/o WHERE caluse ?
>
>No.
>
>>Can you create an index on cl_dob field and run query again?
>
>There is already an index on cl_dob.
>
>Kev


So the Filtering I was expecting on cl_dob probably is exchanged for the use of the index Client1 ?
I'ld try to get to my result in single steps and time/optimize those - even if at first sight at least some operations can be made in a single step. Just typing along without too much thinking so check your needs...

select ;
      cl_ref as Ref_CL, min(EVL(re_date, {^9000-12-31})) as dMin, {..} as dGoMonth 
    from referral ;
    where re_date<>{..} ; && Dunno if this clashes with your business case if only checked here - think about it
    group by 1 ;
    into cursor T_Border readwrite

&& probably the worst place, but gives you a baseline to compare different approaches !
replace all dGoMonth with  GOMONTH(dMin, -216) in T_Border 

select * ;
  from person ;
  join T_Border ;
    on cl_ref = Ref_CL  and cl_dob > dGoMonth

*-- or 

select * ;
  from person ;
  join T_Border ;
    on cl_ref = Ref_CL  
    where cl_dob > dGoMonth 

*-- or 

select * ;
  from person ;
  join T_Border ;
    on cl_ref = Ref_CL  
    where cl_dob > GOMONTH(dMin, -216)  && substract time for replace here <g>

*-- or 

select * ;
  from person ;
  join T_Border ;
    on cl_ref = Ref_CL  
    where cl_dob + 1 > dGoMonth +1  && surely rushmore turned off here !

*-- or 

select *, dGoMonth ;
  from person ;
  join T_Border ;
    on cl_ref = Ref_CL  
    having cl_dob > dGoMonth    & second step for second step - doesn' t look good, but try anyway

this is a two step process - I hope I haven't overlooked a reason for your 3 Table join..

HTH

thomas