Christian Rank <christian(dot)rank(at)rz(dot)uni-passau(dot)de> writes:
> ... according to the docs, the validity of a constraint should be
> checked after each statement unless this behaviour is altered with a SET
> CONSTRAINTS statement.
"Statement" means "interactive command" in that context --- in other
words, the constraints won't be checked until after control returns from
your function.
regards, tom lane