attempt to fix duplicate rows (issue #155)

Author: funbringer

Diff for: src/hooks.c

@@ -369,6 +369,8 @@ pathman_rel_pathlist_hook(PlannerInfo *root,
 		 *					   FROM test.tmp2 t2
 		 *					   WHERE id = t.id);
 		 *
+		 * or unions, multilevel partitioning, etc.
+		 *
 		 * Since we disable optimizations on 9.5, we
 		 * have to skip parent table that has already
 		 * been expanded by standard inheritance.
@@ -378,23 +380,18 @@ pathman_rel_pathlist_hook(PlannerInfo *root,
 			foreach (lc, root->append_rel_list)
 			{
 				AppendRelInfo  *appinfo = (AppendRelInfo *) lfirst(lc);
-				RangeTblEntry  *cur_parent_rte,
-							   *cur_child_rte;
-
-				/*  This 'appinfo' is not for this child */
-				if (appinfo->child_relid != rti)
-					continue;
-
-				cur_parent_rte = root->simple_rte_array[appinfo->parent_relid];
-				cur_child_rte  = rte; /* we already have it, saves time */
 
-				/* This child == its own parent table! */
-				if (cur_parent_rte->relid == cur_child_rte->relid)
+				/*
+				 * If there's an 'appinfo', it means that somebody
+				 * (PG?) has already processed this partitioned table
+				 * and added its children to the plan.
+				 */
+				if (appinfo->child_relid == rti)
 					return;
 			}
 		}
 
-		/* Make copy of partitioning expression and fix Var's  varno attributes */
+		/* Make copy of partitioning expression and fix Var's varno attributes */
 		part_expr = PrelExpressionForRelid(prel, rti);
 
 		/* Get partitioning-related clauses (do this before append_child_relation()) */

Diff for: src/planner_tree_modification.c

@@ -343,10 +343,7 @@ disable_standard_inheritance(Query *parse, transform_query_cxt *context)
 			/* Proceed if table is partitioned by pg_pathman */
 			if ((prel = get_pathman_relation_info(rte->relid)) != NULL)
 			{
-				/*
-				 * HACK: unset the 'inh' flag to disable standard
-				 * planning. We'll set it again later.
-				 */
+				/* HACK: unset the 'inh' flag to disable standard planning */
 				rte->inh = false;
 
 				/* Try marking it using PARENTHOOD_ALLOWED */
@@ -569,7 +566,7 @@ partition_filter_visitor(Plan *plan, void *context)
 void
 assign_rel_parenthood_status(RangeTblEntry *rte,
 							 rel_parenthood_status new_status)
-{	
+{
 	Assert(rte->rtekind != RTE_CTE);
 
 	/* HACK: set relevant bits in RTE */