From b45c5a8be0f5c0babfd6af86b9d06bdd76d15e00 Mon Sep 17 00:00:00 2001
From: Karol Sobczak <karol.sobczak@karolsobczak.com>
Date: Thu, 11 Oct 2018 16:25:46 +0200
Subject: [PATCH] Extract addJoinsWithDifferentDistributions method

---
 .../rule/DetermineJoinDistributionType.java   | 27 +++++++++----------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/DetermineJoinDistributionType.java b/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/DetermineJoinDistributionType.java
index cf898b36e5b0..9059e7fcf248 100644
--- a/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/DetermineJoinDistributionType.java
+++ b/presto-main/src/main/java/com/facebook/presto/sql/planner/iterative/rule/DetermineJoinDistributionType.java
@@ -92,23 +92,10 @@ public static boolean canReplicate(JoinNode joinNode, Context context)
 
     private PlanNode getCostBasedJoin(JoinNode joinNode, Context context)
     {
-        CostProvider costProvider = context.getCostProvider();
         List<PlanNodeWithCost> possibleJoinNodes = new ArrayList<>();
 
-        if (!mustPartition(joinNode) && canReplicate(joinNode, context)) {
-            possibleJoinNodes.add(getJoinNodeWithCost(costProvider, joinNode.withDistributionType(REPLICATED)));
-        }
-        if (!mustReplicate(joinNode, context)) {
-            possibleJoinNodes.add(getJoinNodeWithCost(costProvider, joinNode.withDistributionType(PARTITIONED)));
-        }
-
-        JoinNode flipped = joinNode.flipChildren();
-        if (!mustPartition(flipped) && canReplicate(flipped, context)) {
-            possibleJoinNodes.add(getJoinNodeWithCost(costProvider, flipped.withDistributionType(REPLICATED)));
-        }
-        if (!mustReplicate(flipped, context)) {
-            possibleJoinNodes.add(getJoinNodeWithCost(costProvider, flipped.withDistributionType(PARTITIONED)));
-        }
+        addJoinsWithDifferentDistributions(joinNode, possibleJoinNodes, context);
+        addJoinsWithDifferentDistributions(joinNode.flipChildren(), possibleJoinNodes, context);
 
         if (possibleJoinNodes.stream().anyMatch(result -> result.getCost().hasUnknownComponents()) || possibleJoinNodes.isEmpty()) {
             return getSyntacticOrderJoin(joinNode, context, AUTOMATIC);
@@ -119,6 +106,16 @@ private PlanNode getCostBasedJoin(JoinNode joinNode, Context context)
         return planNodeOrderings.min(possibleJoinNodes).getPlanNode();
     }
 
+    private void addJoinsWithDifferentDistributions(JoinNode joinNode, List<PlanNodeWithCost> possibleJoinNodes, Context context)
+    {
+        if (!mustPartition(joinNode) && canReplicate(joinNode, context)) {
+            possibleJoinNodes.add(getJoinNodeWithCost(context.getCostProvider(), joinNode.withDistributionType(REPLICATED)));
+        }
+        if (!mustReplicate(joinNode, context)) {
+            possibleJoinNodes.add(getJoinNodeWithCost(context.getCostProvider(), joinNode.withDistributionType(PARTITIONED)));
+        }
+    }
+
     private PlanNode getSyntacticOrderJoin(JoinNode joinNode, Context context, JoinDistributionType joinDistributionType)
     {
         if (mustPartition(joinNode)) {