Re: Final Patch for GROUPING SETS

On Fri, Jan 02, 2015 at 03:55:23PM -0600, Jim Nasby wrote:
> On 12/31/14, 3:05 PM, Noah Misch wrote:
> >On Wed, Dec 31, 2014 at 05:33:43PM +0000, Andrew Gierth wrote:
> >>>>>>>> >>>>>"Noah" == Noah Misch<noah(at)leadboat(dot)com> writes:
> >>>
> >>> Noah> Suppose one node orchestrated all sorting and aggregation.
> >>>
> >>>Well, that has the downside of making it into an opaque blob, without
> >>>actually gaining much.
> >The opaque-blob criticism is valid. As for not gaining much, well, the gain I
> >sought was to break this stalemate. You and Tom have expressed willingness to
> >accept the read I/O multiplier of the CTE approach. You and I are willing to
> >swallow an architecture disruption, namely a tuplestore acting as a side
> >channel between executor nodes. Given your NACK, I agree that it fails to
> >move us toward consensus and therefore does not gain much. Alas.
>
> I haven't read the full discussion in depth, but is what we'd want here is the ability to feed tuples to more than one node simultaneously?

A similar comment appeared shortly upthread. Given a planner and executor
capable of that, we would do so here. Changing the planner and executor
architecture to support it is its own large, open-ended project.