Thomas Munro <thomas.munro@enterprisedb.com> writes:
> One practical problem that came up was the need for executor nodes to
> get a chance to do that kind of cleanup before the DSM segment is
> detached. In my patch series I introduced a new node API
> ExecNodeDetach to allow for that. Andres objected that the need for
> that is evidence that the existing protocol is broken and should be
> fixed instead. I'm looking into that.
The thing that you really have to worry about for this kind of proposal
is "what if the query errors out and we never get to ExecEndNode"?
It's particularly nasty if you're talking about parallel queries where
maybe only one or some of the processes involved detect an error.
regards, tom lane