You've to use 11 as a second parameter to display JOIN optimization

SYS(3054,11,"cmemvar")

>This was part of what I couldn't quite work out. The two seemd to conflict.
>
>The SYS(3054,1,"cmemvar") doesn't display info on the actual JOIN.
>
>My understanding is that this will be optimized if a key is exists that matches the right side of the JOIN???
>
>Regards
>Geoff