I wrote:
> I still think that we really need to add a check in ExecProcNode().
Actually ... to what extent could a check in ExecInitNode() substitute
for that? Or do we need both? How about ExecEndNode() and ExecReScan()?
You could argue that the latter two tree traversals are unlikely either to
consume more stack than ExecInitNode() or to be called from a more deeply
nested point. So maybe they're okay. But I'm not sure I believe that
initialization stack needs always exceed execution stack needs, though
sometimes they might.
regards, tom lane