Function create_functionscan_path

src/backend/optimizer/util/pathnode.c:3078–3254

* create_functionscan_path * Creates a path corresponding to a sequential scan of a function, * returning the pathnode. */

 *	  returning the pathnode.
 */
Path *
create_functionscan_path(PlannerInfo *root, RelOptInfo *rel,
						 RangeTblEntry *rte,
						 List *pathkeys, Relids required_outer)
{
	Path	   *pathnode = makeNode(Path);
	ListCell   *lc;

	pathnode->pathtype = T_FunctionScan;
	pathnode->parent = rel;
	pathnode->pathtarget = rel->reltarget;
	pathnode->param_info = get_baserel_parampathinfo(root, rel,
													 required_outer);
	pathnode->parallel_aware = false;
	pathnode->parallel_safe = rel->consider_parallel;
	pathnode->parallel_workers = 0;
	pathnode->pathkeys = pathkeys;

	/*
	 * Decide where to execute the FunctionScan.
	 */
	if (Gp_role == GP_ROLE_DISPATCH)
	{
		char		exec_location = PROEXECLOCATION_ANY;
		bool		contain_mutables = false;
		bool		contain_outer_params = false;

		/*
		 * If the function desires to run on segments, mark randomly-distributed.
		 * If expression contains mutable functions, evaluate it on entry db.
		 * Otherwise let it be evaluated in the same slice as its parent operator.
		 */
		Assert(rte->rtekind == RTE_FUNCTION);

		foreach (lc, rel->baserestrictinfo)
		{
			RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);

			if (rinfo->contain_outer_query_references)
			{
				contain_outer_params = true;
				break;
			}
		}

		foreach (lc, rte->functions)
		{
			RangeTblFunction *rtfunc = (RangeTblFunction *) lfirst(lc);

			if (rtfunc->funcexpr && IsA(rtfunc->funcexpr, FuncExpr))
			{
				FuncExpr   *funcexpr = (FuncExpr *) rtfunc->funcexpr;
				char		this_exec_location;

				this_exec_location = func_exec_location(funcexpr->funcid);

				switch (this_exec_location)
				{