trigger functions can only be called as triggers

Peter Eisentraut <peter_e@gmx.net> writes:

Is there a reason why the function manager allows calling trigger functions
outside of triggers and forces the PLs to catch this case themselves? Is
there a case where calling trigger functions directly is useful?

I think it's a matter of not wanting to slow down *all* function calls
with an error check that's useless for most.

regards, tom lane