Re: [HACKERS] WITH RECURSIVE patch V0.1

[ catching up on back email ]

Gregory Stark <stark(at)enterprisedb(dot)com> writes:
> "Yoshiyuki Asaba" <y-asaba(at)sraoss(dot)co(dot)jp> writes:
>> Recursive query does not consume stack. The server enters an infinite
>> loop without consuming stack. Stack-depth error does not happen.

> We could have a separate guc variable which limits the maximum number of
> levels of recursive iterations. That might be a useful feature for DBAs that
> want to limit their users from issuing an infinite query.

This whole thread seems to be proposing more and more complicated
solutions for what is really a non-problem given Yoshiyuki-san's point.
It's trivial to construct SQL queries that will run for longer than the
MTBF of your hardware --- eg, forget a few join constraints. We've
gotten along fine with nothing but query cancel and statement_timeout
for that, and I've seen no one proposing that we need to "fix it".
We don't disallow you from writing an infinite loop in plpgsql, either.

I think this patch is plenty complicated enough without adding useless
restrictive options.

regards, tom lane