Using a 'magic value' to represent an unknown value generally does not seem to be a good idea.  Most of us have been in the situation where the user has...

Very good. For a while there I was convinced that the lunatics had finally taken control of the asylum.

to be fair, it does cover backup as well 🙂

Overall any backup and recovery is complicated in complicated cases - but many cases are not complicated and the GUI interface despised by some is generally easy to use and...

Ok guys, so the spelling etc could have been better but as someone whose first language is English English, I despair at some of the spelling I see from people...

Lutz was correct is saying that the behaviour of the examples is caused by the behaviour of sql predicates involving nulls rather than outer join, as was his description of...