Function ExecFindMatchingSubPlans

src/backend/executor/execPartition.c:2245–2345

* ExecFindMatchingSubPlans * Determine which subplans match the pruning steps detailed in * 'prunestate' for the current comparison expression values. * * Here we assume we may evaluate PARAM_EXEC Params. * * GPDB: 'join_prune_paramids' can contain a list of PARAM_EXEC Param IDs * containing results that were computed earlier by PartitionSelector * nodes. */

 * nodes.
 */
Bitmapset *
ExecFindMatchingSubPlans(PartitionPruneState *prunestate,
						 EState *estate,
						 int nplans, List *join_prune_paramids)
{
	Bitmapset  *result = NULL;
	MemoryContext oldcontext;
	int			i;
	Bitmapset  *join_selected = NULL;

	if (join_prune_paramids)
	{
		ListCell   *lc;

		join_selected = bms_add_range(join_selected, 0, nplans - 1);

		foreach (lc, join_prune_paramids)
		{
			int			paramid = lfirst_int(lc);
			ParamExecData *param;
			PartitionSelectorState *psstate;

			param = &(estate->es_param_exec_vals[paramid]);
			Assert(param->execPlan == NULL);
			Assert(!param->isnull);
			psstate = (PartitionSelectorState *) DatumGetPointer(param->value);

			if (psstate == NULL)
			{
				/*
				 * The planner should have ensured that the Partition Selector
				 * is fully executed before the Append.
				 */
				elog(WARNING, "partition selector was not fully executed");
			}
			else
			{
				Assert(IsA(psstate, PartitionSelectorState));

				join_selected = bms_intersect(join_selected,
											  psstate->part_prune_result);
			}
		}


		if (!prunestate)
		{
			/* rely entirely on partition selectors */
			return join_selected;
		}
	}

	/*
	 * If !do_exec_prune, we've got problems because
	 * ExecFindInitialMatchingSubPlans will not have bothered to update
	 * prunestate for whatever pruning it did.
	 */
	Assert(prunestate->do_exec_prune);