Looks like I had a long line :)

But you are correct, it works when I remove this comment. During testing of course I did not copy the comment and was thrown to a wrong conclusion. But now it works with the UNIONs.

Still the UNION is much faster than any other approach I tested so far.

>As I said try to remove the question mark in your comment
>

> /* Not necessary ? */
>

>
>to
>

> /* Not necessary */
>