> Hmm how if an upper level node needs to store (for future use) the > TupleTableSlot* returned by lower level node, e.g. I create a specialized > Sort Node which needs to read all tuples from lower level nodes. In this > case, would it be necessary and sufficient to make a copy the TupleTableSlot
It would be a pretty crummy way to approach it, because a Slot is not intended to be a compact representation. You probably want to use a tuplestore or tuplesort object instead.
