Re: Avoid needless copy in nodeMaterial - Mailing list pgsql-patches

From Neil Conway
Subject Re: Avoid needless copy in nodeMaterial
Date
Msg-id 1192510535.6133.28.camel@goldbach
Whole thread Raw
In response to Re: Avoid needless copy in nodeMaterial  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-patches
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



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