Greg Stark <stark@mit.edu> writes:
> It's hard to imagine how the planner could possibly be pluggable in a
> generally useful way. It sounds like putting an insurmountable barrier
> in place that blocks a feature that would be useful in the Executor.
But it's *not* useful without a credible way to modify the planner.
> Frankly I think the planner is hard enough to change when you have
> full access to the source I can't imagine trying to manipulate it from
> a distance like this.
Yeah. To tell the truth, I'm not really convinced that purely-plugin
addition of new plan node types is going to be worth anything. I think
pretty much any interesting project (for example, the parallelization of
Append nodes that was mumbled about above) is going to require changes
that won't fit within such an infrastructure. Still, I'm willing to
accept a patch for plugin plan nodes, *if* it addresses the hard part
of that problem and not only the easy part.
regards, tom lane
