Svein Erling Tysvaer wrote:

> > (b.transdate > (select transdate from vlastpay v
> > where company=2 and v.custno = b.custno))
>
> There is no alias to company, so it could be either v.company or
> b.company. I would expect Firebird to give an error for such ambiguous
> queries, but maybe I'm wrong or you not using Firebird 1.5.3.

It does work even with "company=2", but it seems to become another
6-hour job :-)

The server is "WI-V6.3.0.4306 Firebird 1.5", according to IBExpert.
Does this mean "1.5.0"?

I'm going to do some experiments concerning indexes, views, and
stored procedures. Perhaps I'll find a way which is significantly
faster than the others.

Anyway, thank you for your discussion on that topic - I've learnt
many new things about optimization and WHERE and HAVING and
subSELECTs :-)

Matthias