Re: poll: CHECK TRIGGER?

On tor, 2012-03-08 at 23:15 +0100, Pavel Stehule wrote:
> But you propose some little bit different than is current plpgsql
> checker and current design.

Is it?  Why?  It looks like exactly the same thing, except that the
interfaces you propose are tightly geared toward checking SQL-like
languages, which looks like a mistake to me.

> It's not bad, but it is some different and it is not useful for
> plpgsql - external stored procedures are different, than SQL
> procedures and probably you will check different issues.
>
> I don't think so multiple checkers and external checkers are necessary
> - if some can living outside, then it should to live outside. Internal
> checker can be one for PL language. It is parametrized - so you can
> control goals of checking.

What would be the qualifications for being an internal or an external
checker?  Why couldn't your plpgsql checker be an external checker?