Add MaterializingStep.

src/Processors/QueryPlan/MaterializingStep.cpp

@@ -0,0 +1,39 @@
+#include <Processors/QueryPlan/MaterializingStep.h>
+#include <Processors/QueryPipeline.h>
+#include <Processors/Transforms/MaterializingTransform.h>
+
+#include <DataStreams/materializeBlock.h>
+
+namespace DB
+{
+
+static ITransformingStep::Traits getTraits()
+{
+    return ITransformingStep::Traits
+    {
+        {
+            .preserves_distinct_columns = true,
+            .returns_single_stream = false,
+            .preserves_number_of_streams = true,
+            .preserves_sorting = true,
+        },
+        {
+            .preserves_number_of_rows = true,
+        }
+    };
+}
+
+MaterializingStep::MaterializingStep(const DataStream & input_stream_)
+    : ITransformingStep(input_stream_, materializeBlock(input_stream_.header), getTraits())
+{
+}
+
+void MaterializingStep::transformPipeline(QueryPipeline & pipeline)
+{
+    pipeline.addSimpleTransform([&](const Block & header)
+    {
+        return std::make_shared<MaterializingTransform>(header);
+    });
+}
+
+}

src/Processors/QueryPlan/MaterializingStep.h

@@ -0,0 +1,18 @@
+#pragma once
+#include <Processors/QueryPlan/ITransformingStep.h>
+
+namespace DB
+{
+
+/// Convert one block structure to another. See ConvertingTransform.
+class MaterializingStep : public ITransformingStep
+{
+public:
+    explicit MaterializingStep(const DataStream & input_stream_);
+
+    String getName() const override { return "Materializing"; }
+
+    void transformPipeline(QueryPipeline & pipeline) override;
+};
+
+}

src/Processors/ya.make

@@ -105,6 +105,7 @@ SRCS(
     QueryPlan/ITransformingStep.cpp
     QueryPlan/LimitByStep.cpp
     QueryPlan/LimitStep.cpp
+    QueryPlan/MaterializingStep.cpp
     QueryPlan/MergeSortingStep.cpp
     QueryPlan/MergingAggregatedStep.cpp
     QueryPlan/MergingSortedStep.cpp