From d0842ee937c61f0a62f87fa7b5bae781edf53acd Mon Sep 17 00:00:00 2001
From: Nikita Taranov <nikita.taranov@clickhouse.com>
Date: Sun, 17 Nov 2024 15:36:22 +0100
Subject: [PATCH] don't squash output for ordinary join for now

---
 src/Processors/QueryPlan/JoinStep.cpp         |  7 +++++--
 .../02236_explain_pipeline_join.reference     | 19 +++++++++----------
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/Processors/QueryPlan/JoinStep.cpp b/src/Processors/QueryPlan/JoinStep.cpp
index 86bc818d266..d81ce2fda17 100644
--- a/src/Processors/QueryPlan/JoinStep.cpp
+++ b/src/Processors/QueryPlan/JoinStep.cpp
@@ -80,8 +80,11 @@ QueryPipelineBuilderPtr JoinStep::updatePipeline(QueryPipelineBuilders pipelines
         keep_left_read_in_order,
         &processors);
 
-    pipeline->addSimpleTransform([&](const Block & header)
-                                 { return std::make_shared<SimpleSquashingChunksTransform>(header, 0, min_block_size_bytes); });
+    if (join->supportParallelJoin())
+    {
+        pipeline->addSimpleTransform([&](const Block & header)
+                                     { return std::make_shared<SimpleSquashingChunksTransform>(header, 0, min_block_size_bytes); });
+    }
 
     return pipeline;
 }
diff --git a/tests/queries/0_stateless/02236_explain_pipeline_join.reference b/tests/queries/0_stateless/02236_explain_pipeline_join.reference
index ba366d89139..73d0ca8cb5e 100644
--- a/tests/queries/0_stateless/02236_explain_pipeline_join.reference
+++ b/tests/queries/0_stateless/02236_explain_pipeline_join.reference
@@ -1,18 +1,17 @@
 (Expression)
 ExpressionTransform
   (Join)
-  SimpleSquashingTransform
-    JoiningTransform 2 → 1
-      (Expression)
+  JoiningTransform 2 → 1
+    (Expression)
+    ExpressionTransform
+      (Limit)
+      Limit
+        (ReadFromSystemNumbers)
+        NumbersRange 0 → 1
+    (Expression)
+    FillingRightJoinSide
       ExpressionTransform
         (Limit)
         Limit
           (ReadFromSystemNumbers)
           NumbersRange 0 → 1
-      (Expression)
-      FillingRightJoinSide
-        ExpressionTransform
-          (Limit)
-          Limit
-            (ReadFromSystemNumbers)
-            NumbersRange 0 → 1