Remove Converting transform and step.

src/Functions/materialize.cpp

-#include <Functions/IFunctionImpl.h>
 #include <Functions/FunctionFactory.h>
+#include <Functions/materialize.h>
 
 
 namespace DB
 {
-namespace
-{
-
-/** materialize(x) - materialize the constant
-  */
-class FunctionMaterialize : public IFunction
-{
-public:
-    static constexpr auto name = "materialize";
-    static FunctionPtr create(const Context &)
-    {
-        return std::make_shared<FunctionMaterialize>();
-    }
-
-    bool useDefaultImplementationForNulls() const override
-    {
-        return false;
-    }
-
-    /// Get the function name.
-    String getName() const override
-    {
-        return name;
-    }
-
-    size_t getNumberOfArguments() const override
-    {
-        return 1;
-    }
-
-    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
-    {
-        return arguments[0];
-    }
-
-    ColumnPtr executeImpl(ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t /*input_rows_count*/) const override
-    {
-        return arguments[0].column->convertToFullColumnIfConst();
-    }
-};
-
-}
 
 void registerFunctionMaterialize(FunctionFactory & factory)
 {

src/Functions/materialize.h

+#pragma once
+#include <Functions/IFunctionImpl.h>
+#include <Functions/FunctionFactory.h>
+
+namespace DB
+{
+
+/** materialize(x) - materialize the constant
+  */
+class FunctionMaterialize : public IFunction
+{
+public:
+    static constexpr auto name = "materialize";
+    static FunctionPtr create(const Context &)
+    {
+        return std::make_shared<FunctionMaterialize>();
+    }
+
+    bool useDefaultImplementationForNulls() const override
+    {
+        return false;
+    }
+
+    /// Get the function name.
+    String getName() const override
+    {
+        return name;
+    }
+
+    size_t getNumberOfArguments() const override
+    {
+        return 1;
+    }
+
+    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
+    {
+        return arguments[0];
+    }
+
+    ColumnPtr executeImpl(ColumnsWithTypeAndName & arguments, const DataTypePtr &, size_t /*input_rows_count*/) const override
+    {
+        return arguments[0].column->convertToFullColumnIfConst();
+    }
+};
+
+}

src/Interpreters/ActionsDAG.cpp

@@ -5,6 +5,7 @@
 #include <Functions/IFunction.h>
 #include <Functions/IFunctionAdaptors.h>
 #include <Functions/FunctionsConversion.h>
+#include <Functions/materialize.h>
 #include <Interpreters/Context.h>
 #include <Interpreters/ExpressionJIT.h>
 #include <IO/WriteBufferFromString.h>
@@ -575,6 +576,11 @@ ActionsDAGPtr ActionsDAG::makeConvertingActions(
     FunctionOverloadResolverPtr func_builder_cast =
             std::make_shared<FunctionOverloadResolverAdaptor>(CastOverloadResolver::createImpl(false));
 
+    FunctionOverloadResolverPtr func_builder_materialize =
+            std::make_shared<FunctionOverloadResolverAdaptor>(
+                    std::make_unique<DefaultOverloadResolver>(
+                            std::make_shared<FunctionMaterialize>()));
+
     std::map<std::string_view, std::list<size_t>> inputs;
     if (mode == MatchColumnsMode::Name)
     {
@@ -641,6 +647,12 @@ ActionsDAGPtr ActionsDAG::makeConvertingActions(
             src_node = &actions_dag->addFunction(func_builder_cast, std::move(children), {}, true);
         }
 
+        if (src_node->column && isColumnConst(*src_node->column))
+        {
+            Inputs children = {src_node};
+            src_node = &actions_dag->addFunction(func_builder_materialize, std::move(children), {}, true);
+        }
+
         if (src_node->result_name != res_elem.name)
             src_node = const_cast<Node *>(&actions_dag->addAlias(src_node->result_name, res_elem.name, true));