diff --git a/dbms/CMakeLists.txt b/dbms/CMakeLists.txt
index f83a6590b9f..ae1b09c4bb8 100644
--- a/dbms/CMakeLists.txt
+++ b/dbms/CMakeLists.txt
@@ -279,7 +279,7 @@ add_library (dbms
 	include/DB/Dictionaries/Embedded/RegionsHierarchies.h
 	include/DB/Dictionaries/Embedded/RegionsNames.h
 	include/DB/Dictionaries/Embedded/TechDataHierarchy.h
-	include/DB/Dictionaries/ExternalDatabaseHelper.h
+	include/DB/Dictionaries/ExternalResultDescription.h
 	include/DB/Interpreters/InterpreterAlterQuery.h
 	include/DB/Interpreters/AggregationCommon.h
 	include/DB/Interpreters/ProcessList.h
diff --git a/dbms/include/DB/Dictionaries/ExternalResultDescription.h b/dbms/include/DB/Dictionaries/ExternalResultDescription.h
new file mode 100644
index 00000000000..453ddc3cd93
--- /dev/null
+++ b/dbms/include/DB/Dictionaries/ExternalResultDescription.h
@@ -0,0 +1,92 @@
+#pragma once
+
+#include <ext/range.hpp>
+#include <DB/Core/Block.h>
+
+
+namespace DB
+{
+
+namespace ErrorCodes
+{
+	extern const int UNKNOWN_TYPE;
+}
+
+/** Общая часть реализации MySQLBlockInputStream, MongoDBBlockInputStream, ODBCBlockInputStream.
+  */
+struct ExternalResultDescription
+{
+	enum struct value_type_t
+	{
+		UInt8,
+		UInt16,
+		UInt32,
+		UInt64,
+		Int8,
+		Int16,
+		Int32,
+		Int64,
+		Float32,
+		Float64,
+		String,
+		Date,
+		DateTime
+	};
+
+	Block sample_block;
+	std::vector<value_type_t> types;
+	std::vector<std::string> names;
+	ConstColumnPlainPtrs sample_columns;
+
+	void init(const Block & sample_block_)
+	{
+		sample_block = sample_block_;
+
+		const auto num_columns = sample_block.columns();
+		types.reserve(num_columns);
+		names.reserve(num_columns);
+		sample_columns.reserve(num_columns);
+
+		for (const auto idx : ext::range(0, num_columns))
+		{
+			const auto & column = sample_block.getByPosition(idx);
+			const auto type = column.type.get();
+
+			if (typeid_cast<const DataTypeUInt8 *>(type))
+				types.push_back(value_type_t::UInt8);
+			else if (typeid_cast<const DataTypeUInt16 *>(type))
+				types.push_back(value_type_t::UInt16);
+			else if (typeid_cast<const DataTypeUInt32 *>(type))
+				types.push_back(value_type_t::UInt32);
+			else if (typeid_cast<const DataTypeUInt64 *>(type))
+				types.push_back(value_type_t::UInt64);
+			else if (typeid_cast<const DataTypeInt8 *>(type))
+				types.push_back(value_type_t::Int8);
+			else if (typeid_cast<const DataTypeInt16 *>(type))
+				types.push_back(value_type_t::Int16);
+			else if (typeid_cast<const DataTypeInt32 *>(type))
+				types.push_back(value_type_t::Int32);
+			else if (typeid_cast<const DataTypeInt64 *>(type))
+				types.push_back(value_type_t::Int64);
+			else if (typeid_cast<const DataTypeFloat32 *>(type))
+				types.push_back(value_type_t::Float32);
+			else if (typeid_cast<const DataTypeFloat64 *>(type))
+				types.push_back(value_type_t::Float64);
+			else if (typeid_cast<const DataTypeString *>(type))
+				types.push_back(value_type_t::String);
+			else if (typeid_cast<const DataTypeDate *>(type))
+				types.push_back(value_type_t::Date);
+			else if (typeid_cast<const DataTypeDateTime *>(type))
+				types.push_back(value_type_t::DateTime);
+			else
+				throw Exception{
+					"Unsupported type " + type->getName(),
+					ErrorCodes::UNKNOWN_TYPE};
+
+			names.emplace_back(column.name);
+			sample_columns.emplace_back(column.column.get());
+		}
+	}
+};
+
+}
diff --git a/dbms/include/DB/Dictionaries/MongoDBBlockInputStream.h b/dbms/include/DB/Dictionaries/MongoDBBlockInputStream.h
index 3e20385f8c9..e95e963510e 100644
--- a/dbms/include/DB/Dictionaries/MongoDBBlockInputStream.h
+++ b/dbms/include/DB/Dictionaries/MongoDBBlockInputStream.h
@@ -8,7 +8,7 @@
 #include <DB/DataTypes/DataTypeDate.h>
 #include <DB/DataTypes/DataTypeDateTime.h>
 #include <DB/Columns/ColumnString.h>
-#include <DB/Dictionaries/ExternalDatabaseHelper.h>
+#include <DB/Dictionaries/ExternalResultDescription.h>
 #include <ext/range.hpp>
 #include <mongo/client/dbclient.h>
 #include <vector>
@@ -31,7 +31,7 @@ public:
 		if (!cursor->more())
 			return;
 
-		helper.init(sample_block);
+		description.init(sample_block);
 	}
 
 	String getName() const override { return "MongoDB"; }
@@ -43,7 +43,7 @@ public:
 	}
 
 private:
-	using value_type_t = ExternalDatabaseHelper::value_type_t;
+	using value_type_t = ExternalResultDescription::value_type_t;
 
 	Block readImpl() override
 	{
@@ -51,7 +51,7 @@ private:
 		if (!cursor->more())
 			return {};
 
-		auto block = helper.sample_block.cloneEmpty();
+		auto block = description.sample_block.cloneEmpty();
 
 		/// cache pointers returned by the calls to getByPosition
 		std::vector<IColumn *> columns(block.columns());
@@ -67,12 +67,12 @@ private:
 
 			for (const auto idx : ext::range(0, size))
 			{
-				const auto & name = helper.names[idx];
+				const auto & name = description.names[idx];
 				const auto value = row[name];
 				if (value.ok())
-					insertValue(columns[idx], helper.types[idx], value, name);
+					insertValue(columns[idx], description.types[idx], value, name);
 				else
-					insertDefaultValue(columns[idx], *helper.sample_columns[idx]);
+					insertDefaultValue(columns[idx], *description.sample_columns[idx]);
 			}
 
 			++num_rows;
@@ -230,7 +230,7 @@ private:
 
 	std::unique_ptr<mongo::DBClientCursor> cursor;
 	const std::size_t max_block_size;
-	ExternalDatabaseHelper helper;
+	ExternalResultDescription description;
 };
 
 }
diff --git a/dbms/include/DB/Dictionaries/MySQLBlockInputStream.h b/dbms/include/DB/Dictionaries/MySQLBlockInputStream.h
index 96acd92a1c9..f967f55f7c4 100644
--- a/dbms/include/DB/Dictionaries/MySQLBlockInputStream.h
+++ b/dbms/include/DB/Dictionaries/MySQLBlockInputStream.h
@@ -7,7 +7,7 @@
 #include <DB/DataTypes/DataTypeDate.h>
 #include <DB/DataTypes/DataTypeDateTime.h>
 #include <DB/Columns/ColumnString.h>
-#include <DB/Dictionaries/ExternalDatabaseHelper.h>
+#include <DB/Dictionaries/ExternalResultDescription.h>
 #include <ext/range.hpp>
 #include <mysqlxx/Query.h>
 #include <mysqlxx/PoolWithFailover.h>
@@ -38,7 +38,7 @@ public:
 					toString(sample_block.columns()) + " expected",
 				ErrorCodes::NUMBER_OF_COLUMNS_DOESNT_MATCH};
 
-		helper.init(sample_block);
+		description.init(sample_block);
 	}
 
 	String getName() const override { return "MySQL"; }
@@ -49,7 +49,7 @@ public:
 	}
 
 private:
-	using value_type_t = ExternalDatabaseHelper::value_type_t;
+	using value_type_t = ExternalResultDescription::value_type_t;
 
 	Block readImpl() override
 	{
@@ -57,7 +57,7 @@ private:
 		if (!row)
 			return {};
 
-		auto block = helper.sample_block.cloneEmpty();
+		auto block = description.sample_block.cloneEmpty();
 
 		/// cache pointers returned by the calls to getByPosition
 		std::vector<IColumn *> columns(block.columns());
@@ -71,9 +71,9 @@ private:
 			{
 				const auto value = row[idx];
 				if (!value.isNull())
-					insertValue(columns[idx], helper.types[idx], value);
+					insertValue(columns[idx], description.types[idx], value);
 				else
-					insertDefaultValue(columns[idx], *helper.sample_columns[idx]);
+					insertDefaultValue(columns[idx], *description.sample_columns[idx]);
 			}
 
 			++num_rows;
@@ -115,7 +115,7 @@ private:
 	mysqlxx::Query query;
 	mysqlxx::UseQueryResult result;
 	const std::size_t max_block_size;
-	ExternalDatabaseHelper helper;
+	ExternalResultDescription description;
 };
 
 }