Re: Add CREATE support to event triggers

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> If it were a question of writing this code once and being done with
> it, that would be unobjectionable in my view. But it isn't.
> Practically every change to gram.y is going to require a corresponding
> change to this stuff. As far as I can see, nobody except me has
> commented on the burden that places on everyone who may wish to add
> syntax support for a new construct in the future, which might mean
> that I'm worrying about something that isn't worth worrying about, but
> what I think is more likely is that nobody's worrying about it right
> now because they haven't had to do it yet.

I haven't been paying much attention to this thread, but I concur with
Robert that adding yet another set of overhead requirements to any
addition of new SQL is not a good thing.

> Just to illustrate the point, consider the CREATE TABLE name OF type
> syntax that Peter added a few years ago. That patch
> (e7b3349a8ad7afaad565c573fbd65fb46af6abbe) had the following impact on
> gram.y:

This analysis is kind of cheating, because adding new syntax hasn't been
only a matter of touching gram.y for a very long time. You invariably
have to touch pg_dump, and you have to touch ruleutils.c unless it's
strictly a DDL-command change. But people are used to those, and the
value of keeping pg_dump working is clear to everybody. Adding a similar
level of burden to support a feature with a narrow use-case seems like
a nonstarter from here. ESPECIALLY if we also have to manually add
regression test cases because there's no easy way to test it directly.

regards, tom lane