Originally Posted by
Andy33
Well, seriously, the Schengen area updates its records of non-EU/EEA citizens who have arrived and departed by scanning passports. The rubber stamp is only essential on non-machine-readable passports which are rare these days, and increasingly airport immigration personnel (most obviously at CDG) don't bother to stamp passports they've successfully scanned even though they're still supposed to. EU passports are never stamped whether the issuing country is in Schengen or not as this is against the rules.
The US and the UK have no visible exit checks at airports at all, but information is fed into immigration databases by the airlines scanning passports at check-in or at the gate. The immigration officers still know next time you arrive when you were last there and how long you stayed. It would be unwise to assume that this source of information doesn't reach Schengen immigration too at airports within the Area.
As far as I'm aware the scanning of the passport does NOT lead to a database check because there is no such database. The only way to check your immigration status are the stamps.
But I am not a law enforcement officer, so don't take me by my word on that. That's the info that is on Wikipedia on the matter and I believe it's true, as I think I can remember that after the Charlie Hebdo attacks there was a discussion going on whether such a database should be introduced.