Re: Avoid needless copy in nodeMaterial

On Tue, 2007-10-16 at 00:34 -0400, Tom Lane wrote:
> Seems like this needs more comments about what's happening, rather
> than less ...

Fair point.

> Also, it looks to me like the plan node's own resultslot might never be
> assigned to at all, when the subplan returns zero rows.  Does this
> corner case still work correctly?

ISTM the node's own result slot wouldn't be assigned to in this case
regardless: (nodeMaterial.c, circa 116)

    outerslot = ExecProcNode(outerNode);
    if (TupIsNull(outerslot))
    {
        node->eof_underlying = true;
        return NULL;
    }

There's no requirement that we must assign to the result slot, AFAICS.

-Neil