Function ExecInitTableFuncScan

src/backend/executor/nodeTableFuncscan.c:109–205

---------------------------------------------------------------- * ExecInitTableFuncscan * ---------------------------------------------------------------- */

 * ----------------------------------------------------------------
 */
TableFuncScanState *
ExecInitTableFuncScan(TableFuncScan *node, EState *estate, int eflags)
{
	TableFuncScanState *scanstate;
	TableFunc  *tf = node->tablefunc;
	TupleDesc	tupdesc;
	int			i;

	/* check for unsupported flags */
	Assert(!(eflags & EXEC_FLAG_MARK));

	/*
	 * TableFuncscan should not have any children.
	 */
	Assert(outerPlan(node) == NULL);
	Assert(innerPlan(node) == NULL);

	/*
	 * create new ScanState for node
	 */
	scanstate = makeNode(TableFuncScanState);
	scanstate->ss.ps.plan = (Plan *) node;
	scanstate->ss.ps.state = estate;
	scanstate->ss.ps.ExecProcNode = ExecTableFuncScan;

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

	/*
	 * initialize source tuple type
	 */
	tupdesc = BuildDescFromLists(tf->colnames,
								 tf->coltypes,
								 tf->coltypmods,
								 tf->colcollations);
	/* and the corresponding scan slot */
	ExecInitScanTupleSlot(estate, &scanstate->ss, tupdesc,
						  &TTSOpsMinimalTuple);

	/*
	 * Initialize result type and projection.
	 */
	ExecInitResultTypeTL(&scanstate->ss.ps);
	ExecAssignScanProjectionInfo(&scanstate->ss);

	/*
	 * initialize child expressions
	 */
	scanstate->ss.ps.qual =
		ExecInitQual(node->scan.plan.qual, &scanstate->ss.ps);

	/* Only XMLTABLE is supported currently */
	scanstate->routine = &XmlTableRoutine;