LocalJoin

multi_column.txt

@@ -31,6 +31,11 @@
 - [ ] PostprocessAlterTableStmtAttachPartition()
 - [x] TargetListOnPartitionColumn()
 - [ ] PartitionColumnForPushedDownSubquery()
+- [ ] CoPartitionedTables()
+- [x] LocalJoin()
+- [ ] SinglePartitionJoin()
+- [ ] ApplySinglePartitionJoin()
+- [ ] MultiJoinTree()
 
 # query pushdown planner
 - [x] RestrictionEquivalenceForPartitionKeys()

src/backend/distributed/planner/multi_join_order.c

@@ -97,7 +97,8 @@ static JoinOrderNode * CartesianProduct(JoinOrderNode *joinNode,
 										JoinType joinType);
 static JoinOrderNode * MakeJoinOrderNode(TableEntry *tableEntry,
 										 JoinRuleType joinRuleType,
-										 List *partitionColumnList, char partitionMethod,
+										 List *partitionColumnListList,
+										 char partitionMethod,
 										 TableEntry *anchorTable);
 
 
@@ -343,11 +344,18 @@ JoinOrderForTable(TableEntry *firstTable, List *tableEntryList, List *joinClause
 	/* create join node for the first table */
 	Oid firstRelationId = firstTable->relationId;
 	uint32 firstTableId = firstTable->rangeTableId;
-	Var *firstPartitionColumn = PartitionColumn(firstRelationId, firstTableId);
+	List *firstPartitionColumnListList = NIL;
+	Var *partitionColumn = NULL;
+	List *partitionColumnList = PartitionColumns(firstRelationId, firstTableId);
+	foreach_ptr(partitionColumn, partitionColumnList)
+	{
+		firstPartitionColumnListList = lappend(
+			firstPartitionColumnListList, list_make1(partitionColumn));
+	}
 	char firstPartitionMethod = PartitionMethod(firstRelationId);
 
 	JoinOrderNode *firstJoinNode = MakeJoinOrderNode(firstTable, firstJoinRule,
-													 list_make1(firstPartitionColumn),
+													 firstPartitionColumnListList,
 													 firstPartitionMethod,
 													 firstTable);
 
@@ -829,7 +837,7 @@ ReferenceJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 		return NULL;
 	}
 	return MakeJoinOrderNode(candidateTable, REFERENCE_JOIN,
-							 currentJoinNode->partitionColumnList,
+							 currentJoinNode->partitionColumnListList,
 							 currentJoinNode->partitionMethod,
 							 currentJoinNode->anchorTable);
 }
@@ -881,7 +889,7 @@ CartesianProductReferenceJoin(JoinOrderNode *currentJoinNode, TableEntry *candid
 		return NULL;
 	}
 	return MakeJoinOrderNode(candidateTable, CARTESIAN_PRODUCT_REFERENCE_JOIN,
-							 currentJoinNode->partitionColumnList,
+							 currentJoinNode->partitionColumnListList,
 							 currentJoinNode->partitionMethod,
 							 currentJoinNode->anchorTable);
 }
@@ -905,8 +913,8 @@ LocalJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 {
 	Oid relationId = candidateTable->relationId;
 	uint32 tableId = candidateTable->rangeTableId;
-	Var *candidatePartitionColumn = PartitionColumn(relationId, tableId);
+	List *candidatePartitionColumnList = PartitionColumns(relationId, tableId);
-	List *currentPartitionColumnList = currentJoinNode->partitionColumnList;
+	List *currentPartitionColumnListList = currentJoinNode->partitionColumnListList;
 	char candidatePartitionMethod = PartitionMethod(relationId);
 	char currentPartitionMethod = currentJoinNode->partitionMethod;
 	TableEntry *currentAnchorTable = currentJoinNode->anchorTable;
@@ -926,14 +934,30 @@ LocalJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 		return NULL;
 	}
 
-	bool joinOnPartitionColumns = JoinOnColumns(currentPartitionColumnList,
+	/*
-												candidatePartitionColumn,
+	 * If the number of partition columns don't match then we cannot do a local
-												applicableJoinClauses);
+	 * join.
-	if (!joinOnPartitionColumns)
+	 */
+	if (list_length(candidatePartitionColumnList) != list_length(
+			currentPartitionColumnListList))
 	{
 		return NULL;
 	}
 
+	Var *candidatePartitionColumn = NULL;
+	List *currentPartitionColumnList = NIL;
+	forboth_ptr(candidatePartitionColumn, candidatePartitionColumnList,
+				currentPartitionColumnList, currentPartitionColumnListList)
+	{
+		bool joinOnPartitionColumns = JoinOnColumns(currentPartitionColumnList,
+													candidatePartitionColumn,
+													applicableJoinClauses);
+		if (!joinOnPartitionColumns)
+		{
+			return NULL;
+		}
+	}
+
 	/* shard interval lists must have 1-1 matching for local joins */
 	bool coPartitionedTables = CoPartitionedTables(currentAnchorTable->relationId,
 												   relationId);
@@ -949,11 +973,20 @@ LocalJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 	 * subsequent joins colocated with this candidate table to correctly be recognized as
 	 * a local join as well.
 	 */
-	currentPartitionColumnList = list_append_unique(currentPartitionColumnList,
+	ListCell *candidatePartitionColumnCell = NULL;
-													candidatePartitionColumn);
+	ListCell *currentPartitionColumnListCell = NULL;
+	forboth(candidatePartitionColumnCell, candidatePartitionColumnList,
+			currentPartitionColumnListCell, currentPartitionColumnListList)
+	{
+		candidatePartitionColumn = lfirst(candidatePartitionColumnCell);
+		currentPartitionColumnList = lfirst(currentPartitionColumnListCell);
+		lfirst(currentPartitionColumnListCell) =
+			list_append_unique(currentPartitionColumnList,
+							   candidatePartitionColumn);
+	}
 
 	JoinOrderNode *nextJoinNode = MakeJoinOrderNode(candidateTable, LOCAL_PARTITION_JOIN,
-													currentPartitionColumnList,
+													currentPartitionColumnListList,
 													currentPartitionMethod,
 													currentAnchorTable);
 
@@ -973,7 +1006,7 @@ static JoinOrderNode *
 SinglePartitionJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 					List *applicableJoinClauses, JoinType joinType)
 {
-	List *currentPartitionColumnList = currentJoinNode->partitionColumnList;
+	List *currentPartitionColumnListList = currentJoinNode->partitionColumnListList;
 	char currentPartitionMethod = currentJoinNode->partitionMethod;
 	TableEntry *currentAnchorTable = currentJoinNode->anchorTable;
 	JoinRuleType currentJoinRuleType = currentJoinNode->joinRuleType;
@@ -981,8 +1014,6 @@ SinglePartitionJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 
 	Oid relationId = candidateTable->relationId;
 	uint32 tableId = candidateTable->rangeTableId;
-	Var *candidatePartitionColumn = PartitionColumn(relationId, tableId);
-	char candidatePartitionMethod = PartitionMethod(relationId);
 
 	/* outer joins are not supported yet */
 	if (IS_OUTER_JOIN(joinType))
@@ -1000,8 +1031,17 @@ SinglePartitionJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 		return NULL;
 	}
 
+	if (list_length(currentPartitionColumnListList) > 1)
+	{
+		/*
+		 * TODO: Implement single partition join for multi column distributed
+		 * tables.
+		 */
+		return NULL;
+	}
 	OpExpr *joinClause =
-		SinglePartitionJoinClause(currentPartitionColumnList, applicableJoinClauses);
+		SinglePartitionJoinClause(currentPartitionColumnListList,
+								  applicableJoinClauses);
 	if (joinClause != NULL)
 	{
 		if (currentPartitionMethod == DISTRIBUTE_BY_HASH)
@@ -1016,29 +1056,41 @@ SinglePartitionJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 			}
 
 			return MakeJoinOrderNode(candidateTable, SINGLE_HASH_PARTITION_JOIN,
-									 currentPartitionColumnList,
+									 currentPartitionColumnListList,
 									 currentPartitionMethod,
 									 currentAnchorTable);
 		}
 		else
 		{
 			return MakeJoinOrderNode(candidateTable, SINGLE_RANGE_PARTITION_JOIN,
-									 currentPartitionColumnList,
+									 currentPartitionColumnListList,
 									 currentPartitionMethod,
 									 currentAnchorTable);
 		}
 	}
 
+	char candidatePartitionMethod = PartitionMethod(relationId);
+
 	/* evaluate re-partitioning the current table only if the rule didn't apply above */
 	if (candidatePartitionMethod != DISTRIBUTE_BY_NONE)
 	{
+		List *candidatePartitionColumnList = PartitionColumns(relationId, tableId);
+		if (list_length(currentPartitionColumnListList) > 1)
+		{
+			/*
+			 * TODO: Implement single partition join for multi column distributed
+			 * tables.
+			 */
+			return NULL;
+		}
+
 		/*
 		 * Create a new unique list (set) with the partition column of the candidate table
 		 * to check if a single repartition join will work for this table. When it works
 		 * the set is retained on the MultiJoinNode for later local join verification.
 		 */
-		List *candidatePartitionColumnList = list_make1(candidatePartitionColumn);
+		List *candidatePartitionColumnListList = list_make1(candidatePartitionColumnList);
-		joinClause = SinglePartitionJoinClause(candidatePartitionColumnList,
+		joinClause = SinglePartitionJoinClause(candidatePartitionColumnListList,
 											   applicableJoinClauses);
 		if (joinClause != NULL)
 		{
@@ -1055,7 +1107,7 @@ SinglePartitionJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 
 				return MakeJoinOrderNode(candidateTable,
 										 SINGLE_HASH_PARTITION_JOIN,
-										 candidatePartitionColumnList,
+										 candidatePartitionColumnListList,
 										 candidatePartitionMethod,
 										 candidateTable);
 			}
@@ -1063,7 +1115,7 @@ SinglePartitionJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 			{
 				return MakeJoinOrderNode(candidateTable,
 										 SINGLE_RANGE_PARTITION_JOIN,
-										 candidatePartitionColumnList,
+										 candidatePartitionColumnListList,
 										 candidatePartitionMethod,
 										 candidateTable);
 			}
@@ -1080,13 +1132,19 @@ SinglePartitionJoin(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
  * clause exists, the function returns NULL.
  */
 OpExpr *
-SinglePartitionJoinClause(List *partitionColumnList, List *applicableJoinClauses)
+SinglePartitionJoinClause(List *partitionColumnListList, List *applicableJoinClauses)
 {
-	if (list_length(partitionColumnList) == 0)
+	if (list_length(partitionColumnListList) == 0)
 	{
 		return NULL;
 	}
 
+	/*
+	 * TODO: Support multi column distributed tables.
+	 */
+	Assert(list_length(partitionColumnListList) == 1);
+	List *partitionColumnList = linitial(partitionColumnListList);
+
 	Var *partitionColumn = NULL;
 	foreach_ptr(partitionColumn, partitionColumnList)
 	{
@@ -1210,7 +1268,7 @@ CartesianProduct(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 	{
 		/* Because of the cartesian product, anchor table information got lost */
 		return MakeJoinOrderNode(candidateTable, CARTESIAN_PRODUCT,
-								 currentJoinNode->partitionColumnList,
+								 currentJoinNode->partitionColumnListList,
 								 currentJoinNode->partitionMethod,
 								 NULL);
 	}
@@ -1222,14 +1280,14 @@ CartesianProduct(JoinOrderNode *currentJoinNode, TableEntry *candidateTable,
 /* Constructs and returns a join-order node with the given arguments */
 JoinOrderNode *
 MakeJoinOrderNode(TableEntry *tableEntry, JoinRuleType joinRuleType,
-				  List *partitionColumnList, char partitionMethod,
+				  List *partitionColumnListList, char partitionMethod,
 				  TableEntry *anchorTable)
 {
 	JoinOrderNode *joinOrderNode = palloc0(sizeof(JoinOrderNode));
 	joinOrderNode->tableEntry = tableEntry;
 	joinOrderNode->joinRuleType = joinRuleType;
 	joinOrderNode->joinType = JOIN_INNER;
-	joinOrderNode->partitionColumnList = partitionColumnList;
+	joinOrderNode->partitionColumnListList = partitionColumnListList;
 	joinOrderNode->partitionMethod = partitionMethod;
 	joinOrderNode->joinClauseList = NIL;
 	joinOrderNode->anchorTable = anchorTable;

src/backend/distributed/planner/multi_logical_planner.c

@@ -62,7 +62,7 @@ typedef struct QualifierWalkerContext
 
 /* Function pointer type definition for apply join rule functions */
 typedef MultiNode *(*RuleApplyFunction) (MultiNode *leftNode, MultiNode *rightNode,
-										 List *partitionColumnList, JoinType joinType,
+										 List *partitionColumnListList, JoinType joinType,
 										 List *joinClauses);
 
 typedef bool (*CheckNodeFunc)(Node *);
@@ -94,38 +94,40 @@ static bool IsSelectClause(Node *clause);
 
 /* Local functions forward declarations for applying joins */
 static MultiNode * ApplyJoinRule(MultiNode *leftNode, MultiNode *rightNode,
-								 JoinRuleType ruleType, List *partitionColumnList,
+								 JoinRuleType ruleType, List *partitionColumnListList,
 								 JoinType joinType, List *joinClauseList);
 static RuleApplyFunction JoinRuleApplyFunction(JoinRuleType ruleType);
 static MultiNode * ApplyReferenceJoin(MultiNode *leftNode, MultiNode *rightNode,
-									  List *partitionColumnList, JoinType joinType,
+									  List *partitionColumnListList, JoinType joinType,
 									  List *joinClauses);
 static MultiNode * ApplyLocalJoin(MultiNode *leftNode, MultiNode *rightNode,
-								  List *partitionColumnList, JoinType joinType,
+								  List *partitionColumnListList, JoinType joinType,
 								  List *joinClauses);
 static MultiNode * ApplySingleRangePartitionJoin(MultiNode *leftNode,
 												 MultiNode *rightNode,
-												 List *partitionColumnList,
+												 List *partitionColumnListList,
 												 JoinType joinType,
 												 List *applicableJoinClauses);
 static MultiNode * ApplySingleHashPartitionJoin(MultiNode *leftNode,
 												MultiNode *rightNode,
-												List *partitionColumnList,
+												List *partitionColumnListList,
 												JoinType joinType,
 												List *applicableJoinClauses);
 static MultiJoin * ApplySinglePartitionJoin(MultiNode *leftNode, MultiNode *rightNode,
-											List *partitionColumnList, JoinType joinType,
+											List *partitionColumnListList, JoinType
+											joinType,
 											List *joinClauses);
 static MultiNode * ApplyDualPartitionJoin(MultiNode *leftNode, MultiNode *rightNode,
-										  List *partitionColumnList, JoinType joinType,
+										  List *partitionColumnListList, JoinType
+										  joinType,
 										  List *joinClauses);
 static MultiNode * ApplyCartesianProductReferenceJoin(MultiNode *leftNode,
 													  MultiNode *rightNode,
-													  List *partitionColumnList,
+													  List *partitionColumnListList,
 													  JoinType joinType,
 													  List *joinClauses);
 static MultiNode * ApplyCartesianProduct(MultiNode *leftNode, MultiNode *rightNode,
-										 List *partitionColumnList, JoinType joinType,
+										 List *partitionColumnListList, JoinType joinType,
 										 List *joinClauses);
 
 
@@ -1663,16 +1665,18 @@ MultiJoinTree(List *joinOrderList, List *collectTableList, List *joinWhereClause
 		{
 			JoinRuleType joinRuleType = joinOrderNode->joinRuleType;
 			JoinType joinType = joinOrderNode->joinType;
-			List *partitionColumnList = joinOrderNode->partitionColumnList;
+			List *partitionColumnListList = joinOrderNode->partitionColumnListList;
 			List *joinClauseList = joinOrderNode->joinClauseList;
 
 			/*
 			 * Build a join node between the top of our join tree and the next
 			 * table in the join order.
+			 * TODO: Don't use linitial(partitionColumnListList)
 			 */
 			MultiNode *newJoinNode = ApplyJoinRule(currentTopNode,
 												   (MultiNode *) collectNode,
-												   joinRuleType, partitionColumnList,
+												   joinRuleType,
+												   partitionColumnListList,
 												   joinType,
 												   joinClauseList);
 
@@ -2025,7 +2029,7 @@ pull_var_clause_default(Node *node)
  */
 static MultiNode *
 ApplyJoinRule(MultiNode *leftNode, MultiNode *rightNode, JoinRuleType ruleType,
-			  List *partitionColumnList, JoinType joinType, List *joinClauseList)
+			  List *partitionColumnListList, JoinType joinType, List *joinClauseList)
 {
 	List *leftTableIdList = OutputTableIdList(leftNode);
 	List *rightTableIdList = OutputTableIdList(rightNode);
@@ -2041,7 +2045,8 @@ ApplyJoinRule(MultiNode *leftNode, MultiNode *rightNode, JoinRuleType ruleType,
 
 	/* call the join rule application function to create the new join node */
 	RuleApplyFunction ruleApplyFunction = JoinRuleApplyFunction(ruleType);
-	MultiNode *multiNode = (*ruleApplyFunction)(leftNode, rightNode, partitionColumnList,
+	MultiNode *multiNode = (*ruleApplyFunction)(leftNode, rightNode,
+												partitionColumnListList,
 												joinType, applicableJoinClauses);
 
 	if (joinType != JOIN_INNER && CitusIsA(multiNode, MultiJoin))
@@ -2096,7 +2101,7 @@ JoinRuleApplyFunction(JoinRuleType ruleType)
  */
 static MultiNode *
 ApplyReferenceJoin(MultiNode *leftNode, MultiNode *rightNode,
-				   List *partitionColumnList, JoinType joinType,
+				   List *partitionColumnListList, JoinType joinType,
 				   List *applicableJoinClauses)
 {
 	MultiJoin *joinNode = CitusMakeNode(MultiJoin);
@@ -2118,7 +2123,7 @@ ApplyReferenceJoin(MultiNode *leftNode, MultiNode *rightNode,
  */
 static MultiNode *
 ApplyCartesianProductReferenceJoin(MultiNode *leftNode, MultiNode *rightNode,
-								   List *partitionColumnList, JoinType joinType,
+								   List *partitionColumnListList, JoinType joinType,
 								   List *applicableJoinClauses)
 {
 	MultiJoin *joinNode = CitusMakeNode(MultiJoin);
@@ -2139,7 +2144,7 @@ ApplyCartesianProductReferenceJoin(MultiNode *leftNode, MultiNode *rightNode,
  */
 static MultiNode *
 ApplyLocalJoin(MultiNode *leftNode, MultiNode *rightNode,
-			   List *partitionColumnList, JoinType joinType,
+			   List *partitionColumnListList, JoinType joinType,
 			   List *applicableJoinClauses)
 {
 	MultiJoin *joinNode = CitusMakeNode(MultiJoin);
@@ -2160,11 +2165,11 @@ ApplyLocalJoin(MultiNode *leftNode, MultiNode *rightNode,
  */
 static MultiNode *
 ApplySingleRangePartitionJoin(MultiNode *leftNode, MultiNode *rightNode,
-							  List *partitionColumnList, JoinType joinType,
+							  List *partitionColumnListList, JoinType joinType,
 							  List *applicableJoinClauses)
 {
 	MultiJoin *joinNode =
-		ApplySinglePartitionJoin(leftNode, rightNode, partitionColumnList, joinType,
+		ApplySinglePartitionJoin(leftNode, rightNode, partitionColumnListList, joinType,
 								 applicableJoinClauses);
 
 	joinNode->joinRuleType = SINGLE_RANGE_PARTITION_JOIN;
@@ -2179,11 +2184,11 @@ ApplySingleRangePartitionJoin(MultiNode *leftNode, MultiNode *rightNode,
  */
 static MultiNode *
 ApplySingleHashPartitionJoin(MultiNode *leftNode, MultiNode *rightNode,
-							 List *partitionColumnList, JoinType joinType,
+							 List *partitionColumnListList, JoinType joinType,
 							 List *applicableJoinClauses)
 {
 	MultiJoin *joinNode =
-		ApplySinglePartitionJoin(leftNode, rightNode, partitionColumnList, joinType,
+		ApplySinglePartitionJoin(leftNode, rightNode, partitionColumnListList, joinType,
 								 applicableJoinClauses);
 
 	joinNode->joinRuleType = SINGLE_HASH_PARTITION_JOIN;
@@ -2199,10 +2204,11 @@ ApplySingleHashPartitionJoin(MultiNode *leftNode, MultiNode *rightNode,
  */
 static MultiJoin *
 ApplySinglePartitionJoin(MultiNode *leftNode, MultiNode *rightNode,
-						 List *partitionColumnList, JoinType joinType,
+						 List *partitionColumnListList, JoinType joinType,
 						 List *applicableJoinClauses)
 {
-	Var *partitionColumn = linitial(partitionColumnList);
+	Assert(list_length(partitionColumnListList) == 1);
+	Var *partitionColumn = linitial(linitial(partitionColumnListList));
 	uint32 partitionTableId = partitionColumn->varno;
 
 	/* create all operator structures up front */
@@ -2215,7 +2221,7 @@ ApplySinglePartitionJoin(MultiNode *leftNode, MultiNode *rightNode,
 	 * column against the join clause's columns. If one of the columns matches,
 	 * we introduce a (re-)partition operator for the other column.
 	 */
-	OpExpr *joinClause = SinglePartitionJoinClause(partitionColumnList,
+	OpExpr *joinClause = SinglePartitionJoinClause(partitionColumnListList,
 												   applicableJoinClauses);
 	Assert(joinClause != NULL);
 
@@ -2339,7 +2345,7 @@ ApplyDualPartitionJoin(MultiNode *leftNode, MultiNode *rightNode,
 /* Creates a cartesian product node that joins the left and the right node. */
 static MultiNode *
 ApplyCartesianProduct(MultiNode *leftNode, MultiNode *rightNode,
-					  List *partitionColumnList, JoinType joinType,
+					  List *partitionColumnListList, JoinType joinType,
 					  List *applicableJoinClauses)
 {
 	MultiCartesianProduct *cartesianNode = CitusMakeNode(MultiCartesianProduct);

src/include/distributed/listutils.h

@@ -54,7 +54,6 @@ typedef struct ListCellAndListWrapper
 		 (((var) = lfirst(var ## CellDoNotUse)) || true); \
 		 var ## CellDoNotUse = lnext_compat(l, var ## CellDoNotUse))
 
-
 /*
  * foreach_int -
  *	  a convenience macro which loops through an int list without needing a
@@ -80,6 +79,35 @@ typedef struct ListCellAndListWrapper
 		 (((var) = lfirst_oid(var ## CellDoNotUse)) || true); \
 		 var ## CellDoNotUse = lnext_compat(l, var ## CellDoNotUse))
 
+/*
+ * forboth_ptr -
+ *	  a convenience macro which loops through a pointer list without needing a
+ *	  ListCell, just a declared pointer variable to store the pointer of the
+ *	  cell in.
+ *
+ *   How it works:
+ *	  - A ListCell is declared with the name {var}CellDoNotUse and used
+ *	    throughout the for loop using ## to concat.
+ *	  - To assign to var it needs to be done in the condition of the for loop,
+ *	    because we cannot use the initializer since a ListCell* variable is
+ *	    declared there.
+ *	  - || true is used to always enter the loop when cell is not null even if
+ *	    var is NULL.
+ */
+#define forboth_ptr(var1, l1, var2, l2) \
+	for (ListCell \
+		 *(var1 ## CellDoNotUse) = list_head(l1) \
+		 , *(var2 ## CellDoNotUse) = list_head(l2) \
+		 ; \
+		 (var1 ## CellDoNotUse) != NULL \
+		 && (((var1) = lfirst(var1 ## CellDoNotUse)) || true) \
+		 && (var2 ## CellDoNotUse) != NULL \
+		 && (((var2) = lfirst(var2 ## CellDoNotUse)) || true) \
+		 ; \
+		 var1 ## CellDoNotUse = lnext_compat(l1, var1 ## CellDoNotUse) \
+		 , var2 ## CellDoNotUse = lnext_compat(l2, var2 ## CellDoNotUse) \
+		 )
+
 /*
  * foreach_ptr_append -
  *	  a convenience macro which loops through a pointer List and can append list

src/include/distributed/multi_join_order.h

@@ -75,7 +75,7 @@ typedef struct JoinOrderNode
 	 * We keep track of all unique partition columns in the relation to correctly find
 	 * join clauses that can be applied locally.
 	 */
-	List *partitionColumnList;
+	List *partitionColumnListList;
 
 	char partitionMethod;
 	List *joinClauseList;       /* not relevant for the first table */

src/test/regress/expected/multi_column_distribution.out

@@ -252,51 +252,16 @@ SELECT * FROM (
     FROM t2 JOIN t3 ON t2.id = t3.id
 ) foo
 ORDER BY 1, 2, 3, 4;
- id | id2 | a | b
+ERROR:  the query contains a join that requires repartitioning
----------------------------------------------------------------------
+HINT:  Set citus.enable_repartition_joins to on to enable repartitioning
-  1 |   1 | 1 | 1
-  1 |   1 | 2 | 1
-  1 |   1 | 4 | 1
-  2 |   3 | 4 | 2
-  2 |   3 | 4 | 4
-  2 |   3 | 5 | 2
-  2 |   3 | 5 | 4
-  2 |   4 | 5 | 2
-  2 |   4 | 5 | 4
-(9 rows)
-
 EXPLAIN
 SELECT * FROM (
     SELECT t2.id, t2.id2, a, b
     FROM t2 JOIN t3 ON t2.id = t3.id
 ) foo
 ORDER BY 1, 2, 3, 4;
-                                                       QUERY PLAN
+ERROR:  the query contains a join that requires repartitioning
----------------------------------------------------------------------
+HINT:  Set citus.enable_repartition_joins to on to enable repartitioning
- Custom Scan (Citus Adaptive)  (cost=0.00..0.00 rows=0 width=0)
-   ->  Distributed Subplan XXX_1
-         ->  Custom Scan (Citus Adaptive)  (cost=0.00..0.00 rows=100000 width=16)
-               Task Count: 4
-               Tasks Shown: One of 4
-               ->  Task
-                     Node: host=localhost port=xxxxx dbname=regression
-                     ->  Merge Join  (cost=285.08..607.40 rows=20808 width=16)
-                           Merge Cond: (t2.id = t3.id)
-                           ->  Sort  (cost=142.54..147.64 rows=2040 width=12)
-                                 Sort Key: t2.id
-                                 ->  Seq Scan on t2_27905504 t2  (cost=0.00..30.40 rows=2040 width=12)
-                           ->  Sort  (cost=142.54..147.64 rows=2040 width=8)
-                                 Sort Key: t3.id
-                                 ->  Seq Scan on t3_27905508 t3  (cost=0.00..30.40 rows=2040 width=8)
-   Task Count: 1
-   Tasks Shown: All
-   ->  Task
-         Node: host=localhost port=xxxxx dbname=regression
-         ->  Sort  (cost=59.83..62.33 rows=1000 width=16)
-               Sort Key: intermediate_result.id, intermediate_result.id2, intermediate_result.a, intermediate_result.b
-               ->  Function Scan on read_intermediate_result intermediate_result  (cost=0.00..10.00 rows=1000 width=16)
-(22 rows)
-
 -- Cannot pushdown if not joining on both distribution columns
 SELECT * FROM (
     SELECT t2.id, t2.id2, a, b