Re: This script will crash the connection

Is there a TODO item here, Tom?

> "Steve Howe" <howe(at)carcass(dot)dhs(dot)org> writes:
> > create rule blah_update as
> > on update to blah
> > do
> > notify TestEvent;
>
> > UPDATE blah SET n1=n1+1; -- Won't crash the connection
> > UPDATE blah SET n1=2 WHERE var_field='aaa' AND n1=1 AND n2=2 AND arr_str IS
> > NULL AND m IS NULL; -- Will crash the connection
>
> The problem here is that the query rewriter tries to hang the query's
> qualification (WHERE clause) onto the rule's action query, so that
> the action query won't be done unless the query finds at least one
> row to update.
>
> NOTIFY commands, being utility statements, don't have qualifications.
> In 7.0 and before, the qual clause just vanished into the ether, and
> so in this example the NOTIFY would execute whether the UPDATE updated
> any rows or not. In 7.1 there is physically noplace to hang the qual
> (no jointree) and thus a crash.
>
> Not sure what to do here. Adding quals to utility statements is right
> out, however --- even if we weren't late in beta, the concept doesn't
> make any sense to me. For one reason, utility statements don't have
> FROM clauses against which to evaluate the quals. I am leaning to the
> idea that we should forbid NOTIFY in rules altogether. Jan, what's your
> thought?
>
> Steve, your immediate move is to use a trigger rather than a rule to
> execute the NOTIFY. Meanwhile, we have to think about what to do...
>
> regards, tom lane
>

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