right recursive joins should be handled by pushdown planner

src/backend/distributed/planner/multi_join_order.c

@@ -71,8 +71,6 @@ static JoinOrderNode * EvaluateJoinRules(List *joinedTableList,
 										 TableEntry *candidateTable,
 										 List *joinClauseList, JoinType joinType);
 static List * RangeTableIdList(List *tableList);
-static JoinType JoinTypeBetweenTables(TableEntry *table1, TableEntry *table2,
-									  JoinRestrictionContext *joinRestrictionContext);
 static RuleEvalFunction JoinRuleEvalFunction(JoinRuleType ruleType);
 static char * JoinRuleName(JoinRuleType ruleType);
 static JoinOrderNode * ReferenceJoin(JoinOrderNode *joinNode, TableEntry *candidateTable,
@@ -327,43 +325,13 @@ JoinOrderList(List *tableEntryList, List *joinClauseList)
 }
 
 
-/*
- * JoinTypeBetweenTables returns join type between given tables.
- */
-static JoinType
-JoinTypeBetweenTables(TableEntry *table1, TableEntry *table2,
-					  JoinRestrictionContext *joinRestrictionContext)
-{
-	uint32 rteIdx1 = table1->rangeTableId;
-	uint32 rteIdx2 = table2->rangeTableId;
-
-	JoinRestriction *joinRestriction = NULL;
-	foreach_ptr(joinRestriction, joinRestrictionContext->joinRestrictionList)
-	{
-		if (bms_is_member(rteIdx1, joinRestriction->innerrelRelids) &&
-			bms_is_member(rteIdx2, joinRestriction->outerrelRelids))
-		{
-			return joinRestriction->joinType;
-		}
-		else if (bms_is_member(rteIdx2, joinRestriction->innerrelRelids) &&
-				 bms_is_member(rteIdx1, joinRestriction->outerrelRelids))
-		{
-			return joinRestriction->joinType;
-		}
-	}
-
-	ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					errmsg("no join is found between tables")));
-}
-
-
 /*
  * FixedJoinOrderList returns the best fixed join order according to
  * applicable join rules for the nodes in the list.
  */
 List *
 FixedJoinOrderList(List *tableEntryList, List *joinClauseList,
-				   JoinRestrictionContext *joinRestrictionContext)
+				   List *joinExprList)
 {
 	List *joinOrderList = NIL;
 	List *joinedTableList = NIL;
@@ -377,8 +345,7 @@ FixedJoinOrderList(List *tableEntryList, List *joinClauseList,
 	{
 		TableEntry *currentTable = (TableEntry *) list_nth(tableEntryList, tableIdx - 1);
 		TableEntry *nextTable = (TableEntry *) list_nth(tableEntryList, tableIdx);
-		JoinType joinType = JoinTypeBetweenTables(currentTable, nextTable,
-												  joinRestrictionContext);
+		JoinType joinType = ((JoinExpr *) list_nth(joinExprList, tableIdx - 1))->jointype;
 
 		if (firstTable)
 		{

src/backend/distributed/planner/multi_logical_planner.c

@@ -153,8 +153,7 @@ MultiLogicalPlanCreate(Query *originalQuery, Query *queryTree,
 	}
 	else
 	{
-		multiQueryNode = MultiNodeTree(queryTree,
-									   plannerRestrictionContext->joinRestrictionContext);
+		multiQueryNode = MultiNodeTree(queryTree);
 	}
 
 	/* add a root node to serve as the permanent handle to the tree */
@@ -563,7 +562,7 @@ SubqueryEntryList(Query *queryTree)
  * group, and limit nodes if they appear in the original query tree.
  */
 MultiNode *
-MultiNodeTree(Query *queryTree, JoinRestrictionContext *joinRestrictionContext)
+MultiNodeTree(Query *queryTree)
 {
 	List *rangeTableList = queryTree->rtable;
 	List *targetEntryList = queryTree->targetList;
@@ -638,8 +637,7 @@ MultiNodeTree(Query *queryTree, JoinRestrictionContext *joinRestrictionContext)
 		}
 
 		/* recursively create child nested multitree */
-		MultiNode *subqueryExtendedNode = MultiNodeTree(subqueryTree,
-														joinRestrictionContext);
+		MultiNode *subqueryExtendedNode = MultiNodeTree(subqueryTree);
 
 		SetChild((MultiUnaryNode *) subqueryCollectNode, (MultiNode *) subqueryNode);
 		SetChild((MultiUnaryNode *) subqueryNode, subqueryExtendedNode);
@@ -667,10 +665,11 @@ MultiNodeTree(Query *queryTree, JoinRestrictionContext *joinRestrictionContext)
 			/* consider outer join qualifications as well */
 			List *allRestrictionClauseList = QualifierList(queryTree->jointree);
 			joinClauseList = JoinClauseList(allRestrictionClauseList);
+			List *joinExprList = JoinExprList(queryTree->jointree);
 
 			/* we simply donot commute joins as we have at least 1 outer join */
 			joinOrderList = FixedJoinOrderList(tableEntryList, joinClauseList,
-											   joinRestrictionContext);
+											   joinExprList);
 		}
 		else
 		{

src/backend/distributed/planner/query_pushdown_planning.c

@@ -111,7 +111,8 @@ static Var * PartitionColumnForPushedDownSubquery(Query *query);
 static bool ContainsReferencesToRelids(Query *query, Relids relids, int *foundRelid);
 static bool ContainsReferencesToRelidsWalker(Node *node,
 											 RelidsReferenceWalkerContext *context);
-
+static bool HasRightRecursiveJoin(FromExpr *fromExpr);
+static bool RightRecursiveJoinExprWalker(Node *node, void *context);
 
 /*
  * ShouldUseSubqueryPushDown determines whether it's desirable to use
@@ -173,6 +174,11 @@ ShouldUseSubqueryPushDown(Query *originalQuery, Query *rewrittenQuery,
 		return true;
 	}
 
+	/* if there is right recursive join, fix join order can not handle it */
+	if (HasRightRecursiveJoin(rewrittenQuery->jointree))
+	{
+		return true;
+	}
 
 	/*
 	 * We process function and VALUES RTEs as subqueries, since the join order planner
@@ -204,6 +210,53 @@ ShouldUseSubqueryPushDown(Query *originalQuery, Query *rewrittenQuery,
 }
 
 
+/*
+ * HasRightRecursiveJoin returns true if join tree contains any right recursive join.
+ * That method should be removed when we support right recursive outer joins at join
+ * order planner.
+ */
+static bool
+HasRightRecursiveJoin(FromExpr *fromExpr)
+{
+	JoinExpr *joinExpr = NULL;
+	foreach_ptr(joinExpr, fromExpr->fromlist)
+	{
+		if (RightRecursiveJoinExprWalker((Node *) joinExpr, NULL))
+		{
+			return true;
+		}
+	}
+
+	return false;
+}
+
+
+/*
+ * RightRecursiveJoinExprWalker returns true if it finds right recursive join
+ * in given join tree.
+ */
+static bool
+RightRecursiveJoinExprWalker(Node *node, void *context)
+{
+	if (node == NULL)
+	{
+		return false;
+	}
+
+	if (IsA(node, JoinExpr))
+	{
+		JoinExpr *joinExpr = (JoinExpr *) node;
+
+		if (joinExpr->rarg && IsA(joinExpr->rarg, JoinExpr))
+		{
+			return true;
+		}
+	}
+
+	return expression_tree_walker(node, RightRecursiveJoinExprWalker, NULL);
+}
+
+
 /*
  * JoinTreeContainsSubquery returns true if the input query contains any subqueries
  * in the join tree (e.g., FROM clause).

src/include/distributed/multi_join_order.h

@@ -93,7 +93,7 @@ extern bool EnableSingleHashRepartitioning;
 extern List * JoinExprList(FromExpr *fromExpr);
 extern List * JoinOrderList(List *rangeTableEntryList, List *joinClauseList);
 extern List * FixedJoinOrderList(List *rangeTableEntryList, List *joinClauseList,
-								 JoinRestrictionContext *joinRestrictionContext);
+								 List *joinExprList);
 extern bool IsApplicableJoinClause(List *leftTableIdList, uint32 rightTableId,
 								   Node *joinClause);
 extern List * ApplicableJoinClauses(List *leftTableIdList, uint32 rightTableId,

src/include/distributed/multi_logical_planner.h

@@ -229,8 +229,7 @@ extern MultiProject * MultiProjectNode(List *targetEntryList);
 extern MultiExtendedOp * MultiExtendedOpNode(Query *queryTree, Query *originalQuery);
 extern DeferredErrorMessage * DeferErrorIfUnsupportedSubqueryRepartition(Query *
 																		 subqueryTree);
-extern MultiNode * MultiNodeTree(Query *queryTree,
-								 JoinRestrictionContext *joinRestrictionContext);
+extern MultiNode * MultiNodeTree(Query *queryTree);
 
 
 #endif   /* MULTI_LOGICAL_PLANNER_H */