PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> It seems that the bitwise shift left operator ignores overflow:
> Is this an expected behavior (a kind of UB)? It's not like an arithmetic
> shift. (The semantic of '1::int4<<-1' is questionable too.)
It's defined to do whatever the C << operator does. That will certainly
not involve throwing an error.
regards, tom lane