Hi Helmut and Alexander!

What happens if you modify your select just a little bit and add 0 to
a.id?

select a.f1,a.f2,b.f1,b.f2,c.f1,c.f2 from t1 a, t2 b, t3 c
where a.id+0=b.t1id and b.id =c.t2id
and a.f1 is null and a.f2 is not null

I generally like the optimizer. If I treat it decently, it gives me
the information I want pretty quickly (it is just that I sometimes
have to feed Firebird with queries that are a bit too demanding for my
liking).

> BTW, when anwsering is something bug in some version or not and what
> about future version, it is very convenient to know version which
> you use :)

Well Ded, I also tend to skip subject lines occationally ;o)

HTH,
Set