Yes, shortly after I posted, i saw poj's reply and thought "Hey, that's even better!". The only nag was, that it's not Perl :-)

On the latter point (and your point), there may still be different views, how the database distinguishes true from false, and how Perl (and/or the respective script) does that. The best way to minimize conflicts seems to be laid out over there (CHECK constraint on the column). But of course, a real Boolean column type would be better.