[remove before merging] Shuffle CHECK TABLE results

src/Interpreters/InterpreterCheckQuery.cpp

@@ -11,6 +11,7 @@
 #include <Common/typeid_cast.h>
 #include <Interpreters/ProcessList.h>
 #include <algorithm>
+#include <random>
 
 #include <Columns/IColumn.h>
 
@@ -140,6 +141,44 @@ private:
     std::atomic_bool is_value_emitted{false};
 };
 
+
+class RandomShuffleTransform : public IAccumulatingTransform
+{
+public:
+    RandomShuffleTransform(const Block & header)
+        : IAccumulatingTransform(header, header)
+    {}
+
+    String getName() const override { return "TableCheckResultEmitter"; }
+
+    void consume(Chunk chunk) override
+    {
+        chunks.emplace_back(std::move(chunk));
+    }
+
+    Chunk generate() override
+    {
+        if (!is_shuffled.exchange(true))
+        {
+            std::random_device rd;
+            std::mt19937 gen(rd());
+            std::shuffle(chunks.begin(), chunks.end(), gen);
+        }
+
+        if (chunks.empty())
+            return {};
+
+        auto chunk = std::move(chunks.back());
+        chunks.pop_back();
+        return chunk;
+    }
+
+private:
+    Chunks chunks;
+    std::atomic_bool is_shuffled{false};
+};
+
+
 }
 
 InterpreterCheckQuery::InterpreterCheckQuery(const ASTPtr & query_ptr_, ContextPtr context_)
@@ -190,6 +229,18 @@ BlockIO InterpreterCheckQuery::execute()
             resize_outport = &resize_processor->getOutputs().front();
         }
 
+        /// TODO: for tesing only, remove after CI passed once
+        if (num_streams > 1)
+        {
+            auto shuffle_processor = std::make_shared<RandomShuffleTransform>(resize_outport->getHeader());
+            auto * input_port = &shuffle_processor->getInputPort();
+            connect(*resize_outport, *input_port);
+            processors->emplace_back(shuffle_processor);
+
+            assert(resize_processor->getOutputs().size() == 1);
+            resize_outport = &shuffle_processor->getOutputs().front();
+        }
+
         if (settings.check_query_single_value_result)
         {
             auto emitter_processor = std::make_shared<TableCheckResultEmitter>();