diff --git a/dbms/include/DB/Storages/MergeTree/MergeTreeReadPool.h b/dbms/include/DB/Storages/MergeTree/MergeTreeReadPool.h
index 1759029ef3f..d4ea74c7a4d 100644
--- a/dbms/include/DB/Storages/MergeTree/MergeTreeReadPool.h
+++ b/dbms/include/DB/Storages/MergeTree/MergeTreeReadPool.h
@@ -20,14 +20,16 @@ struct MergeTreeReadTask
 	const NamesAndTypesList & columns;
 	const NamesAndTypesList & pre_columns;
 	const bool remove_prewhere_column;
+	const MarkRanges & all_ranges;
 
 	MergeTreeReadTask(const MergeTreeData::DataPartPtr & data_part, const MarkRanges & ranges,
 					  const std::size_t part_index_in_query, const Names & ordered_names,
 					  const NameSet & column_name_set, const NamesAndTypesList & columns,
-					  const NamesAndTypesList & pre_columns, const bool remove_prewhere_column)
+					  const NamesAndTypesList & pre_columns, const bool remove_prewhere_column,
+					  const MarkRanges & all_ranges)
 		: data_part{data_part}, mark_ranges{ranges}, part_index_in_query{part_index_in_query},
 		  ordered_names{ordered_names}, column_name_set{column_name_set}, columns{columns}, pre_columns{pre_columns},
-		  remove_prewhere_column{remove_prewhere_column}
+		  remove_prewhere_column{remove_prewhere_column}, all_ranges{all_ranges}
 	{}
 };
 
@@ -115,7 +117,7 @@ public:
 
 		return std::make_unique<MergeTreeReadTask>(
 			part.data_part, ranges_to_get_from_part, part.part_index_in_query, ordered_names, column_name_set, columns,
-			pre_columns, remove_prewhere_column);
+			pre_columns, remove_prewhere_column, per_part_all_ranges[part_id]);
 	}
 
 public:
@@ -124,6 +126,8 @@ public:
 	{
 		for (const auto & part : parts)
 		{
+			per_part_all_ranges.push_back(part.ranges);
+
 			per_part_columns_lock.push_back(std::make_unique<Poco::ScopedReadRWLock>(
 				part.data_part->columns_lock));
 
@@ -238,6 +242,7 @@ public:
 
 	std::vector<std::unique_ptr<Poco::ScopedReadRWLock>> per_part_columns_lock;
 	RangesInDataParts parts;
+	std::vector<MarkRanges> per_part_all_ranges;
 	std::vector<std::size_t> per_part_sum_marks;
 	std::size_t sum_marks;
 	MergeTreeData & data;
diff --git a/dbms/include/DB/Storages/MergeTree/MergeTreeReader.h b/dbms/include/DB/Storages/MergeTree/MergeTreeReader.h
index c55e67412f1..64aeb1076d5 100644
--- a/dbms/include/DB/Storages/MergeTree/MergeTreeReader.h
+++ b/dbms/include/DB/Storages/MergeTree/MergeTreeReader.h
@@ -203,13 +203,15 @@ public:
 		fillMissingColumnsImpl(res, ordered_names, true);
 	}
 
+	const MergeTreeData::DataPartPtr & getDataPart() const { return data_part; }
+
 private:
 	struct Stream
 	{
 		MarkCache::MappedPtr marks;
 		ReadBuffer * data_buffer;
-		Poco::SharedPtr<CachedCompressedReadBuffer> cached_buffer;
-		Poco::SharedPtr<CompressedReadBufferFromFile> non_cached_buffer;
+		std::unique_ptr<CachedCompressedReadBuffer> cached_buffer;
+		std::unique_ptr<CompressedReadBufferFromFile> non_cached_buffer;
 		std::string path_prefix;
 		size_t max_mark_range;
 
@@ -269,15 +271,15 @@ private:
 
 			if (uncompressed_cache)
 			{
-				cached_buffer = new CachedCompressedReadBuffer(path_prefix + ".bin", uncompressed_cache,
-															   estimated_size, aio_threshold, buffer_size);
-				data_buffer = &*cached_buffer;
+				cached_buffer = std::make_unique<CachedCompressedReadBuffer>(
+					path_prefix + ".bin", uncompressed_cache, estimated_size, aio_threshold, buffer_size);
+				data_buffer = cached_buffer.get();
 			}
 			else
 			{
-				non_cached_buffer = new CompressedReadBufferFromFile(path_prefix + ".bin", estimated_size,
-																	 aio_threshold, buffer_size);
-				data_buffer = &*non_cached_buffer;
+				non_cached_buffer = std::make_unique<CompressedReadBufferFromFile>(
+					path_prefix + ".bin", estimated_size, aio_threshold, buffer_size);
+				data_buffer = non_cached_buffer.get();
 			}
 		}
 
diff --git a/dbms/include/DB/Storages/MergeTree/MergeTreeThreadBlockInputStream.h b/dbms/include/DB/Storages/MergeTree/MergeTreeThreadBlockInputStream.h
index 6cc887ebf0c..a5330cfaf46 100644
--- a/dbms/include/DB/Storages/MergeTree/MergeTreeThreadBlockInputStream.h
+++ b/dbms/include/DB/Storages/MergeTree/MergeTreeThreadBlockInputStream.h
@@ -77,16 +77,18 @@ protected:
 
 				const auto path = storage.getFullPath() + task->data_part->name + '/';
 
-				reader = std::make_unique<MergeTreeReader>(
-					path, task->data_part, task->columns, owned_uncompressed_cache.get(), owned_mark_cache.get(),
-					storage,
-					task->mark_ranges, min_bytes_to_use_direct_io, max_read_buffer_size);
+				if (!reader || reader->getDataPart() != task->data_part)
+				{
+					reader = std::make_unique<MergeTreeReader>(
+						path, task->data_part, task->columns, owned_uncompressed_cache.get(), owned_mark_cache.get(),
+						storage, task->all_ranges, min_bytes_to_use_direct_io, max_read_buffer_size);
 
-				if (prewhere_actions)
-					pre_reader = std::make_unique<MergeTreeReader>(
-						path, task->data_part, task->pre_columns, owned_uncompressed_cache.get(),
-						owned_mark_cache.get(),
-						storage, task->mark_ranges, min_bytes_to_use_direct_io, max_read_buffer_size);
+					if (prewhere_actions)
+						pre_reader = std::make_unique<MergeTreeReader>(
+							path, task->data_part, task->pre_columns, owned_uncompressed_cache.get(),
+							owned_mark_cache.get(), storage, task->all_ranges, min_bytes_to_use_direct_io,
+							max_read_buffer_size);
+				}
 			}
 
 			res = readFromPart();