>>>Why do you need SET EXECT OFF for this type of the index expression to work?
>>
>>Because you are setting relation into the child table on the part of the current index key.
>
>Thank you very much for your help.
>
>Just wanted to be sure I am doing it right, since I have not used the SET RELATION in a long time.
>
>When I switched to the index expression I set relation to
>
>

>SET RELATION TO STR(ORDER_NO,6) INTO MYCHILDTABLE
>

>
>The above is correct, right?

Looks right to me.