Function build_path_tlist

src/backend/optimizer/plan/createplan.c:898–931

* Build a target list (ie, a list of TargetEntry) for the Path's output. * * This is almost just make_tlist_from_pathtarget(), but we also have to * deal with replacing nestloop params. */

 * deal with replacing nestloop params.
 */
static List *
build_path_tlist(PlannerInfo *root, Path *path)
{
	List	   *tlist = NIL;
	Index	   *sortgrouprefs = path->pathtarget->sortgrouprefs;
	int			resno = 1;
	ListCell   *v;

	foreach(v, path->pathtarget->exprs)
	{
		Node	   *node = (Node *) lfirst(v);
		TargetEntry *tle;

		/*
		 * If it's a parameterized path, there might be lateral references in
		 * the tlist, which need to be replaced with Params.  There's no need
		 * to remake the TargetEntry nodes, so apply this to each list item
		 * separately.
		 */
		if (path->param_info)
			node = replace_nestloop_params(root, node);

		tle = makeTargetEntry((Expr *) node,
							  resno,
							  NULL,
							  false);
		if (sortgrouprefs)
			tle->ressortgroupref = sortgrouprefs[resno - 1];

		tlist = lappend(tlist, tle);
		resno++;
	}
	return tlist;
}

/*
 * use_physical_tlist