Function ExecConditionalAssignProjectionInfo

src/backend/executor/execUtils.c:611–636

---------------- * ExecConditionalAssignProjectionInfo * * as ExecAssignProjectionInfo, but store NULL rather than building projection * info if no projection is required * ---------------- */

 * ----------------
 */
void
ExecConditionalAssignProjectionInfo(PlanState *planstate, TupleDesc inputDesc,
									Index varno)
{
	if (tlist_matches_tupdesc(planstate,
							  planstate->plan->targetlist,
							  varno,
							  inputDesc))
	{
		planstate->ps_ProjInfo = NULL;
		planstate->resultopsset = planstate->scanopsset;
		planstate->resultopsfixed = planstate->scanopsfixed;
		planstate->resultops = planstate->scanops;
	}
	else
	{
		if (!planstate->ps_ResultTupleSlot)
		{
			ExecInitResultSlot(planstate, &TTSOpsVirtual);
			planstate->resultops = &TTSOpsVirtual;
			planstate->resultopsfixed = true;
			planstate->resultopsset = true;
		}
		ExecAssignProjectionInfo(planstate, inputDesc);
	}
}

static bool
tlist_matches_tupdesc(PlanState *ps, List *tlist, Index varno, TupleDesc tupdesc)