diff --git a/dbms/include/DB/Storages/MergeTree/MergeTreeData.h b/dbms/include/DB/Storages/MergeTree/MergeTreeData.h
index a83c32117e7..20f700957b9 100644
--- a/dbms/include/DB/Storages/MergeTree/MergeTreeData.h
+++ b/dbms/include/DB/Storages/MergeTree/MergeTreeData.h
@@ -64,6 +64,8 @@ namespace ErrorCodes
   * - Collapsing - при склейке кусков "схлопывать"
   *   пары записей с разными значениями sign_column для одного значения первичного ключа.
   *   (см. CollapsingSortedBlockInputStream.h)
+  * - Replacing - при склейке кусков, при совпадении PK, оставлять только одну строчку
+  *             - последнюю, либо, если задан столбец "версия" - последнюю среди строчек с максимальной версией.
   * - Summing - при склейке кусков, при совпадении PK суммировать все числовые столбцы, не входящие в PK.
   * - Aggregating - при склейке кусков, при совпадении PK, делается слияние состояний столбцов-агрегатных функций.
   * - Unsorted - при склейке кусков, данные не упорядочиваются, а всего лишь конкатенируются;
@@ -192,6 +194,20 @@ public:
 		Summing 	= 2,
 		Aggregating = 3,
 		Unsorted 	= 4,
+		Replacing	= 5,
+	};
+
+	/// Настройки для разных режимов работы.
+	struct MergingParams
+	{
+		/// Для Collapsing режима.
+		String sign_column;
+
+		/// Для Summing режима. Если пустое - то выбирается автоматически.
+		Names columns_to_sum;
+
+		/// Для Replacing режима. Может быть пустым.
+		String version_column;
 	};
 
 	static void doNothing(const String & name) {}
@@ -215,8 +231,7 @@ public:
 					const ASTPtr & sampling_expression_, /// nullptr, если семплирование не поддерживается.
 					size_t index_granularity_,
 					Mode mode_,
-					const String & sign_column_,			/// Для Collapsing режима.
-					const Names & columns_to_sum_,			/// Для Summing режима. Если пустое - то выбирается автоматически.
+					const MergingParams & merging_params_,
 					const MergeTreeSettings & settings_,
 					const String & log_name_,
 					bool require_part_metadata_,
@@ -433,10 +448,7 @@ public:
 
 	/// Режим работы - какие дополнительные действия делать при мердже.
 	const Mode mode;
-	/// Для схлопывания записей об изменениях, если используется Collapsing режим работы.
-	const String sign_column;
-	/// Для суммирования, если используется Summing режим работы.
-	const Names columns_to_sum;
+	const MergingParams merging_params;
 
 	const MergeTreeSettings settings;
 
diff --git a/dbms/include/DB/Storages/StorageMergeTree.h b/dbms/include/DB/Storages/StorageMergeTree.h
index a965757f596..214191f18f1 100644
--- a/dbms/include/DB/Storages/StorageMergeTree.h
+++ b/dbms/include/DB/Storages/StorageMergeTree.h
@@ -41,8 +41,7 @@ public:
 		const ASTPtr & sampling_expression_, /// nullptr, если семплирование не поддерживается.
 		size_t index_granularity_,
 		MergeTreeData::Mode mode_,
-		const String & sign_column_,			/// Для Collapsing режима.
-		const Names & columns_to_sum_,			/// Для Summing режима.
+		const MergeTreeData::MergingParams & merging_params_,
 		const MergeTreeSettings & settings_);
 
 	void shutdown() override;
@@ -185,8 +184,7 @@ private:
 		const ASTPtr & sampling_expression_, /// nullptr, если семплирование не поддерживается.
 		size_t index_granularity_,
 		MergeTreeData::Mode mode_,
-		const String & sign_column_,
-		const Names & columns_to_sum_,
+		const MergeTreeData::MergingParams & merging_params_,
 		const MergeTreeSettings & settings_);
 
 	/** Определяет, какие куски нужно объединять, и объединяет их.
diff --git a/dbms/include/DB/Storages/StorageReplicatedMergeTree.h b/dbms/include/DB/Storages/StorageReplicatedMergeTree.h
index c717108b608..7d8c3e13607 100644
--- a/dbms/include/DB/Storages/StorageReplicatedMergeTree.h
+++ b/dbms/include/DB/Storages/StorageReplicatedMergeTree.h
@@ -87,8 +87,7 @@ public:
 		const ASTPtr & sampling_expression_, /// nullptr, если семплирование не поддерживается.
 		size_t index_granularity_,
 		MergeTreeData::Mode mode_,
-		const String & sign_column_,		/// Для Collapsing режима.
-		const Names & columns_to_sum_,		/// Для Summing режима.
+		const MergeTreeData::MergingParams & merging_params_,
 		const MergeTreeSettings & settings_);
 
 	void shutdown() override;
@@ -319,8 +318,7 @@ private:
 		const ASTPtr & sampling_expression_,
 		size_t index_granularity_,
 		MergeTreeData::Mode mode_,
-		const String & sign_column_,
-		const Names & columns_to_sum_,
+		const MergeTreeData::MergingParams & merging_params_,
 		const MergeTreeSettings & settings_);
 
 	/// Инициализация.
diff --git a/dbms/src/Storages/MergeTree/MergeTreeData.cpp b/dbms/src/Storages/MergeTree/MergeTreeData.cpp
index 458ed8c2d64..c1068acaa4c 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeData.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeData.cpp
@@ -37,8 +37,7 @@ MergeTreeData::MergeTreeData(
 	const String & date_column_name_, const ASTPtr & sampling_expression_,
 	size_t index_granularity_,
 	Mode mode_,
-	const String & sign_column_,
-	const Names & columns_to_sum_,
+	const MergingParams & merging_params_,
 	const MergeTreeSettings & settings_,
 	const String & log_name_,
 	bool require_part_metadata_,
@@ -46,7 +45,7 @@ MergeTreeData::MergeTreeData(
     : ITableDeclaration{materialized_columns_, alias_columns_, column_defaults_}, context(context_),
 	date_column_name(date_column_name_), sampling_expression(sampling_expression_),
 	index_granularity(index_granularity_),
-	mode(mode_), sign_column(sign_column_), columns_to_sum(columns_to_sum_),
+	mode(mode_), merging_params(merging_params_),
 	settings(settings_), primary_expr_ast(primary_expr_ast_ ? primary_expr_ast_->clone() : nullptr),
 	require_part_metadata(require_part_metadata_),
 	full_path(full_path_), columns(columns_),
@@ -79,15 +78,16 @@ MergeTreeData::MergeTreeData(
 	/// Проверяем, что столбец sign_column, если нужен, существует, и имеет тип Int8.
 	if (mode == Collapsing)
 	{
-		if (sign_column.empty())
+		if (merging_params.sign_column.empty())
 			throw Exception("Logical error: Sign column for storage CollapsingMergeTree is empty", ErrorCodes::LOGICAL_ERROR);
 
 		for (const auto & column : *columns)
 		{
-			if (column.name == sign_column)
+			if (column.name == merging_params.sign_column)
 			{
 				if (!typeid_cast<const DataTypeInt8 *>(column.type.get()))
-					throw Exception("Sign column (" + sign_column + ") for storage CollapsingMergeTree must have type Int8."
+					throw Exception("Sign column (" + merging_params.sign_column + ")"
+						" for storage CollapsingMergeTree must have type Int8."
 						" Provided column of type " + column.type->getName() + ".", ErrorCodes::BAD_TYPE_OF_FIELD);
 				break;
 			}
@@ -95,12 +95,12 @@ MergeTreeData::MergeTreeData(
 	}
 
 	/// Если заданы columns_to_sum, проверяем, что такие столбцы существуют.
-	if (!columns_to_sum.empty())
+	if (!merging_params.columns_to_sum.empty())
 	{
 		if (mode != Summing)
 			throw Exception("List of columns to sum for MergeTree cannot be specified in all modes except Summing.", ErrorCodes::LOGICAL_ERROR);
 
-		for (const auto & column_to_sum : columns_to_sum)
+		for (const auto & column_to_sum : merging_params.columns_to_sum)
 			if (columns->end() == std::find_if(columns->begin(), columns->end(),
 				[&](const NameAndTypePair & name_and_type) { return column_to_sum == name_and_type.name; }))
 				throw Exception("Column " + column_to_sum + " listed in columns to sum does not exist in table declaration.");
@@ -463,7 +463,7 @@ void MergeTreeData::checkAlter(const AlterCommands & params)
 	if (primary_expr)
 		keys = primary_expr->getRequiredColumns();
 
-	keys.push_back(sign_column);
+	keys.push_back(merging_params.sign_column);
 
 	std::sort(keys.begin(), keys.end());
 
diff --git a/dbms/src/Storages/MergeTree/MergeTreeDataMerger.cpp b/dbms/src/Storages/MergeTree/MergeTreeDataMerger.cpp
index c833df657cf..513012e9d4b 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeDataMerger.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeDataMerger.cpp
@@ -425,12 +425,12 @@ MergeTreeData::MutableDataPartPtr MergeTreeDataMerger::mergePartsToTemporaryPart
 
 		case MergeTreeData::Collapsing:
 			merged_stream = std::make_unique<CollapsingSortedBlockInputStream>(
-				src_streams, data.getSortDescription(), data.sign_column, DEFAULT_MERGE_BLOCK_SIZE);
+				src_streams, data.getSortDescription(), data.merging_params.sign_column, DEFAULT_MERGE_BLOCK_SIZE);
 			break;
 
 		case MergeTreeData::Summing:
 			merged_stream = std::make_unique<SummingSortedBlockInputStream>(
-				src_streams, data.getSortDescription(), data.columns_to_sum, DEFAULT_MERGE_BLOCK_SIZE);
+				src_streams, data.getSortDescription(), data.merging_params.columns_to_sum, DEFAULT_MERGE_BLOCK_SIZE);
 			break;
 
 		case MergeTreeData::Aggregating:
@@ -438,6 +438,11 @@ MergeTreeData::MutableDataPartPtr MergeTreeDataMerger::mergePartsToTemporaryPart
 				src_streams, data.getSortDescription(), DEFAULT_MERGE_BLOCK_SIZE);
 			break;
 
+		case MergeTreeData::Replacing:	/// TODO
+			merged_stream = std::make_unique<MergingSortedBlockInputStream>(
+				src_streams, data.getSortDescription(), DEFAULT_MERGE_BLOCK_SIZE);
+			break;
+
 		case MergeTreeData::Unsorted:
 			merged_stream = std::make_unique<ConcatBlockInputStream>(src_streams);
 			break;
@@ -680,12 +685,12 @@ MergeTreeData::PerShardDataParts MergeTreeDataMerger::reshardPartition(
 
 		case MergeTreeData::Collapsing:
 			merged_stream = std::make_unique<CollapsingSortedBlockInputStream>(
-				src_streams, data.getSortDescription(), data.sign_column, DEFAULT_MERGE_BLOCK_SIZE);
+				src_streams, data.getSortDescription(), data.merging_params.sign_column, DEFAULT_MERGE_BLOCK_SIZE);
 			break;
 
 		case MergeTreeData::Summing:
 			merged_stream = std::make_unique<SummingSortedBlockInputStream>(
-				src_streams, data.getSortDescription(), data.columns_to_sum, DEFAULT_MERGE_BLOCK_SIZE);
+				src_streams, data.getSortDescription(), data.merging_params.columns_to_sum, DEFAULT_MERGE_BLOCK_SIZE);
 			break;
 
 		case MergeTreeData::Aggregating:
@@ -693,6 +698,11 @@ MergeTreeData::PerShardDataParts MergeTreeDataMerger::reshardPartition(
 				src_streams, data.getSortDescription(), DEFAULT_MERGE_BLOCK_SIZE);
 			break;
 
+		case MergeTreeData::Replacing: 	/// TODO
+			merged_stream = std::make_unique<MergingSortedBlockInputStream>(
+				src_streams, data.getSortDescription(), DEFAULT_MERGE_BLOCK_SIZE);
+			break;
+
 		case MergeTreeData::Unsorted:
 			merged_stream = std::make_unique<ConcatBlockInputStream>(src_streams);
 			break;
diff --git a/dbms/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp b/dbms/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp
index e63ffbbaf5a..902a65aa23a 100644
--- a/dbms/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp
@@ -518,8 +518,8 @@ BlockInputStreams MergeTreeDataSelectExecutor::read(
 		std::vector<String> add_columns = data.getPrimaryExpression()->getRequiredColumns();
 		column_names_to_read.insert(column_names_to_read.end(), add_columns.begin(), add_columns.end());
 
-		if (!data.sign_column.empty())
-			column_names_to_read.push_back(data.sign_column);
+		if (!data.merging_params.sign_column.empty())
+			column_names_to_read.push_back(data.merging_params.sign_column);
 
 		std::sort(column_names_to_read.begin(), column_names_to_read.end());
 		column_names_to_read.erase(std::unique(column_names_to_read.begin(), column_names_to_read.end()), column_names_to_read.end());
@@ -799,7 +799,7 @@ BlockInputStreams MergeTreeDataSelectExecutor::spreadMarkRangesAmongThreadsFinal
 	BlockInputStreams res;
 	if (to_merge.size() == 1)
 	{
-		if (!data.sign_column.empty())
+		if (!data.merging_params.sign_column.empty())
 		{
 			ExpressionActionsPtr sign_filter_expression;
 			String sign_filter_column;
@@ -822,17 +822,22 @@ BlockInputStreams MergeTreeDataSelectExecutor::spreadMarkRangesAmongThreadsFinal
 				break;
 
 			case MergeTreeData::Collapsing:
-				merged = new CollapsingFinalBlockInputStream(to_merge, data.getSortDescription(), data.sign_column);
+				merged = new CollapsingFinalBlockInputStream(to_merge, data.getSortDescription(), data.merging_params.sign_column);
 				break;
 
 			case MergeTreeData::Summing:
-				merged = new SummingSortedBlockInputStream(to_merge, data.getSortDescription(), data.columns_to_sum, max_block_size);
+				merged = new SummingSortedBlockInputStream(to_merge,
+					data.getSortDescription(), data.merging_params.columns_to_sum, max_block_size);
 				break;
 
 			case MergeTreeData::Aggregating:
 				merged = new AggregatingSortedBlockInputStream(to_merge, data.getSortDescription(), max_block_size);
 				break;
 
+			case MergeTreeData::Replacing:	/// TODO
+				merged = new MergingSortedBlockInputStream(to_merge, data.getSortDescription(), max_block_size);
+				break;
+
 			case MergeTreeData::Unsorted:
 				throw Exception("UnsortedMergeTree doesn't support FINAL", ErrorCodes::LOGICAL_ERROR);
 		}
@@ -866,7 +871,7 @@ void MergeTreeDataSelectExecutor::createPositiveSignCondition(
 	arguments->children.push_back(sign_ptr);
 	arguments->children.push_back(one_ptr);
 
-	sign->name = data.sign_column;
+	sign->name = data.merging_params.sign_column;
 	sign->kind = ASTIdentifier::Column;
 
 	one->value = Field(static_cast<Int64>(1));
diff --git a/dbms/src/Storages/StorageFactory.cpp b/dbms/src/Storages/StorageFactory.cpp
index 931a5165751..c6cd07da596 100644
--- a/dbms/src/Storages/StorageFactory.cpp
+++ b/dbms/src/Storages/StorageFactory.cpp
@@ -544,11 +544,7 @@ For further info please read the documentation: https://clickhouse.yandex-team.r
 		ASTPtr sampling_expression;
 		UInt64 index_granularity;
 
-		/// Для Collapsing.
-		String sign_column_name;
-
-		/// Для Summing.
-		Names columns_to_sum;
+		MergeTreeData::MergingParams merging_params;
 
 		if (replicated)
 		{
@@ -573,7 +569,7 @@ For further info please read the documentation: https://clickhouse.yandex-team.r
 		if (mode == MergeTreeData::Collapsing)
 		{
 			if (auto ast = typeid_cast<ASTIdentifier *>(&*args.back()))
-				sign_column_name = ast->name;
+				merging_params.sign_column = ast->name;
 			else
 				throw Exception(String("Sign column name must be an unquoted string") + verbose_help, ErrorCodes::BAD_ARGUMENTS);
 
@@ -584,7 +580,7 @@ For further info please read the documentation: https://clickhouse.yandex-team.r
 			/// Если последний элемент - не index granularity (литерал), то это - список суммируемых столбцов.
 			if (!typeid_cast<const ASTLiteral *>(&*args.back()))
 			{
-				columns_to_sum = extractColumnNames(args.back());
+				merging_params.columns_to_sum = extractColumnNames(args.back());
 				args.pop_back();
 			}
 		}
@@ -617,14 +613,14 @@ For further info please read the documentation: https://clickhouse.yandex-team.r
 				zookeeper_path, replica_name, attach, data_path, database_name, table_name,
 				columns, materialized_columns, alias_columns, column_defaults,
 				context, primary_expr_list, date_column_name,
-				sampling_expression, index_granularity, mode, sign_column_name, columns_to_sum,
+				sampling_expression, index_granularity, mode, merging_params,
 				context.getMergeTreeSettings());
 		else
 			return StorageMergeTree::create(
 				data_path, database_name, table_name,
 				columns, materialized_columns, alias_columns, column_defaults,
 				context, primary_expr_list, date_column_name,
-				sampling_expression, index_granularity, mode, sign_column_name, columns_to_sum,
+				sampling_expression, index_granularity, mode, merging_params,
 				context.getMergeTreeSettings());
 	}
 	else
diff --git a/dbms/src/Storages/StorageMergeTree.cpp b/dbms/src/Storages/StorageMergeTree.cpp
index 19a3a69c2d8..fc6c3456c87 100644
--- a/dbms/src/Storages/StorageMergeTree.cpp
+++ b/dbms/src/Storages/StorageMergeTree.cpp
@@ -33,8 +33,7 @@ StorageMergeTree::StorageMergeTree(
 	const ASTPtr & sampling_expression_, /// nullptr, если семплирование не поддерживается.
 	size_t index_granularity_,
 	MergeTreeData::Mode mode_,
-	const String & sign_column_,
-	const Names & columns_to_sum_,
+	const MergeTreeData::MergingParams & merging_params_,
 	const MergeTreeSettings & settings_)
     : IStorage{materialized_columns_, alias_columns_, column_defaults_},
 	path(path_), database_name(database_name_), table_name(table_name_), full_path(path + escapeForFileName(table_name) + '/'),
@@ -42,7 +41,7 @@ StorageMergeTree::StorageMergeTree(
 	data(full_path, columns_,
 		 materialized_columns_, alias_columns_, column_defaults_,
 		 context_, primary_expr_ast_, date_column_name_,
-		 sampling_expression_, index_granularity_,mode_, sign_column_, columns_to_sum_,
+		 sampling_expression_, index_granularity_,mode_, merging_params_,
 		 settings_, database_name_ + "." + table_name, false),
 	reader(data), writer(data), merger(data),
 	increment(0),
@@ -86,15 +85,14 @@ StoragePtr StorageMergeTree::create(
 	const ASTPtr & sampling_expression_,
 	size_t index_granularity_,
 	MergeTreeData::Mode mode_,
-	const String & sign_column_,
-	const Names & columns_to_sum_,
+	const MergeTreeData::MergingParams & merging_params_,
 	const MergeTreeSettings & settings_)
 {
 	auto res = new StorageMergeTree{
 		path_, database_name_, table_name_,
 		columns_, materialized_columns_, alias_columns_, column_defaults_,
 		context_, primary_expr_ast_, date_column_name_,
-		sampling_expression_, index_granularity_, mode_, sign_column_, columns_to_sum_, settings_
+		sampling_expression_, index_granularity_, mode_, merging_params_, settings_
 	};
 	StoragePtr res_ptr = res->thisPtr();
 
diff --git a/dbms/src/Storages/StorageReplicatedMergeTree.cpp b/dbms/src/Storages/StorageReplicatedMergeTree.cpp
index 92d5bfd17fc..eba0743c87f 100644
--- a/dbms/src/Storages/StorageReplicatedMergeTree.cpp
+++ b/dbms/src/Storages/StorageReplicatedMergeTree.cpp
@@ -190,8 +190,7 @@ StorageReplicatedMergeTree::StorageReplicatedMergeTree(
 	const ASTPtr & sampling_expression_,
 	size_t index_granularity_,
 	MergeTreeData::Mode mode_,
-	const String & sign_column_,
-	const Names & columns_to_sum_,
+	const MergeTreeData::MergingParams & merging_params_,
 	const MergeTreeSettings & settings_)
     : IStorage{materialized_columns_, alias_columns_, column_defaults_}, context(context_),
 	current_zookeeper(context.getZooKeeper()), database_name(database_name_),
@@ -201,7 +200,7 @@ StorageReplicatedMergeTree::StorageReplicatedMergeTree(
 	data(full_path, columns_,
 		materialized_columns_, alias_columns_, column_defaults_,
 		context_, primary_expr_ast_, date_column_name_,
-		sampling_expression_, index_granularity_, mode_, sign_column_, columns_to_sum_,
+		sampling_expression_, index_granularity_, mode_, merging_params_,
 		settings_, database_name_ + "." + table_name, true,
 		[this] (const std::string & name) { enqueuePartForCheck(name); }),
 	reader(data), writer(data), merger(data), fetcher(data), sharded_partition_uploader_client(*this),
@@ -274,7 +273,7 @@ StorageReplicatedMergeTree::StorageReplicatedMergeTree(
 		unreplicated_data.reset(new MergeTreeData(unreplicated_path, columns_,
 			materialized_columns_, alias_columns_, column_defaults_,
 			context_, primary_expr_ast_,
-			date_column_name_, sampling_expression_, index_granularity_, mode_, sign_column_, columns_to_sum_, settings_,
+			date_column_name_, sampling_expression_, index_granularity_, mode_, merging_params_, settings_,
 			database_name_ + "." + table_name + "[unreplicated]", false));
 
 		unreplicated_data->loadDataParts(skip_sanity_checks);
@@ -333,8 +332,7 @@ StoragePtr StorageReplicatedMergeTree::create(
 	const ASTPtr & sampling_expression_,
 	size_t index_granularity_,
 	MergeTreeData::Mode mode_,
-	const String & sign_column_,
-	const Names & columns_to_sum_,
+	const MergeTreeData::MergingParams & merging_params_,
 	const MergeTreeSettings & settings_)
 {
 	auto res = new StorageReplicatedMergeTree{
@@ -343,7 +341,7 @@ StoragePtr StorageReplicatedMergeTree::create(
 		columns_, materialized_columns_, alias_columns_, column_defaults_,
 		context_, primary_expr_ast_, date_column_name_,
 		sampling_expression_, index_granularity_, mode_,
-		sign_column_, columns_to_sum_, settings_};
+		merging_params_, settings_};
 
 	StoragePtr res_ptr = res->thisPtr();
 
@@ -418,7 +416,7 @@ namespace
 				<< "sampling expression: " << formattedAST(data.sampling_expression) << "\n"
 				<< "index granularity: " << data.index_granularity << "\n"
 				<< "mode: " << static_cast<int>(data.mode) << "\n"
-				<< "sign column: " << data.sign_column << "\n"
+				<< "sign column: " << data.merging_params.sign_column << "\n"
 				<< "primary key: " << formattedAST(data.primary_expr_ast) << "\n";
 		}
 
@@ -477,9 +475,9 @@ namespace
 			String read_sign_column;
 			in >> read_sign_column;
 
-			if (read_sign_column != data.sign_column)
+			if (read_sign_column != data.merging_params.sign_column)
 				throw Exception("Existing table metadata in ZooKeeper differs in sign column."
-					" Stored in ZooKeeper: " + read_sign_column + ", local: " + data.sign_column,
+					" Stored in ZooKeeper: " + read_sign_column + ", local: " + data.merging_params.sign_column,
 					ErrorCodes::METADATA_MISMATCH);
 
 			in >> "\nprimary key: ";