Function ExecInitResult

src/backend/executor/nodeResult.c:247–318

---------------------------------------------------------------- * ExecInitResult * * Creates the run-time state information for the result node * produced by the planner and initializes outer relations * (child nodes). * ---------------------------------------------------------------- */

 * ----------------------------------------------------------------
 */
ResultState *
ExecInitResult(Result *node, EState *estate, int eflags)
{
	ResultState *resstate;

	/* check for unsupported flags */
	Assert(!(eflags & (EXEC_FLAG_MARK | EXEC_FLAG_BACKWARD)) ||
		   outerPlan(node) != NULL);

	/*
	 * create state structure
	 */
	resstate = makeNode(ResultState);
	resstate->ps.plan = (Plan *) node;
	resstate->ps.state = estate;
	resstate->ps.ExecProcNode = ExecResult;

	resstate->rs_done = false;
	resstate->rs_checkqual = (node->resconstantqual == NULL) ? false : true;

	/*
	 * Miscellaneous initialization
	 *
	 * create expression context for node
	 */
	ExecAssignExprContext(estate, &resstate->ps);

	/*
	 * initialize child nodes
	 */
	outerPlanState(resstate) = ExecInitNode(outerPlan(node), estate, eflags);

	/*
	 * we don't use inner plan
	 */
	Assert(innerPlan(node) == NULL);

	/*
	 * Initialize result slot, type and projection.
	 */
	ExecInitResultTupleSlotTL(&resstate->ps, &TTSOpsVirtual);
	ExecAssignProjectionInfo(&resstate->ps, NULL);

	/*
	 * initialize child expressions
	 */
	resstate->ps.qual =
		ExecInitQual(node->plan.qual, (PlanState *) resstate);
	resstate->resconstantqual =
		ExecInitQual((List *) node->resconstantqual, (PlanState *) resstate);

	/*
	 * initialize hash filter
	 */
	if (node->numHashFilterCols > 0)
	{
		int			currentSliceId = estate->currentSliceId;
		ExecSlice *currentSlice = &estate->es_sliceTable->slices[currentSliceId];