diff --git a/dbms/include/DB/Common/HashTable/HashMap.h b/dbms/include/DB/Common/HashTable/HashMap.h
index b36d62e9539..20cbb616aa2 100644
--- a/dbms/include/DB/Common/HashTable/HashMap.h
+++ b/dbms/include/DB/Common/HashTable/HashMap.h
@@ -74,6 +74,25 @@ struct HashMapCell
 };
 
 
+template <typename Key, typename TMapped, typename Hash, typename TState = HashTableNoState>
+struct HashMapCellWithSavedHash : public HashMapCell<Key, TMapped, Hash, TState>
+{
+	typedef HashMapCell<Key, TMapped, Hash, TState> Base;
+
+	size_t saved_hash;
+
+	HashMapCellWithSavedHash() : Base() {}
+	HashMapCellWithSavedHash(const Key & key_, const typename Base::State & state) : Base(key_, state) {}
+	HashMapCellWithSavedHash(const typename Base::value_type & value_, const typename Base::State & state) : Base(value_, state) {}
+
+	bool keyEquals(const Key & key_) const { return this->value.first == key_; }
+	bool keyEquals(const HashMapCellWithSavedHash & other) const { return saved_hash == other.saved_hash && this->value.first == other.value.first; }
+
+	void setHash(size_t hash_value) { saved_hash = hash_value; }
+	size_t getHash(const Hash & hash) const { return saved_hash; }
+};
+
+
 template
 <
 	typename Key,
@@ -112,3 +131,14 @@ template
 	typename Allocator = HashTableAllocator
 >
 using HashMap = HashMapTable<Key, HashMapCell<Key, Mapped, Hash>, Hash, Grower, Allocator>;
+
+
+template
+<
+	typename Key,
+	typename Mapped,
+	typename Hash = DefaultHash<Key>,
+	typename Grower = HashTableGrower<>,
+	typename Allocator = HashTableAllocator
+>
+using HashMapWithSavedHash = HashMapTable<Key, HashMapCellWithSavedHash<Key, Mapped, Hash>, Hash, Grower, Allocator>;
diff --git a/dbms/include/DB/Common/HashTable/HashSet.h b/dbms/include/DB/Common/HashTable/HashSet.h
index c9ce37c6627..6c53d34f9f2 100644
--- a/dbms/include/DB/Common/HashTable/HashSet.h
+++ b/dbms/include/DB/Common/HashTable/HashSet.h
@@ -14,15 +14,16 @@
 template
 <
 	typename Key,
+	typename TCell,
 	typename Hash = DefaultHash<Key>,
 	typename Grower = HashTableGrower<>,
 	typename Allocator = HashTableAllocator
 >
-class HashSet : public HashTable<Key, HashTableCell<Key, Hash>, Hash, Grower, Allocator>
+class HashSetTable : public HashTable<Key, TCell, Hash, Grower, Allocator>
 {
 public:
-	typedef HashSet<Key, Hash, Grower, Allocator> Self;
-	typedef HashTableCell<Key, Hash> Cell;
+	typedef HashSetTable<Key, TCell, Hash, Grower, Allocator> Self;
+	typedef TCell Cell;
 
 	void merge(const Self & rhs)
 	{
@@ -55,3 +56,41 @@ public:
 		}
 	}
 };
+
+
+template <typename Key, typename Hash, typename TState = HashTableNoState>
+struct HashSetCellWithSavedHash : public HashTableCell<Key, Hash, TState>
+{
+	typedef HashTableCell<Key, Hash, TState> Base;
+
+	size_t saved_hash;
+
+	HashSetCellWithSavedHash() : Base() {}
+	HashSetCellWithSavedHash(const Key & key_, const typename Base::State & state) : Base(key_, state) {}
+
+	bool keyEquals(const Key & key_) const { return this->key == key_; }
+	bool keyEquals(const HashSetCellWithSavedHash & other) const { return saved_hash == other.saved_hash && this->key == other.key; }
+
+	void setHash(size_t hash_value) { saved_hash = hash_value; }
+	size_t getHash(const Hash & hash) const { return saved_hash; }
+};
+
+
+template
+<
+	typename Key,
+	typename Hash = DefaultHash<Key>,
+	typename Grower = HashTableGrower<>,
+	typename Allocator = HashTableAllocator
+>
+using HashSet = HashSetTable<Key, HashTableCell<Key, Hash>, Hash, Grower, Allocator>;
+
+
+template
+<
+	typename Key,
+	typename Hash = DefaultHash<Key>,
+	typename Grower = HashTableGrower<>,
+	typename Allocator = HashTableAllocator
+>
+using HashSetWithSavedHash = HashSetTable<Key, HashSetCellWithSavedHash<Key, Hash>, Hash, Grower, Allocator>;
diff --git a/dbms/include/DB/Interpreters/Aggregator.h b/dbms/include/DB/Interpreters/Aggregator.h
index a79858db5bb..25f6cca3d39 100644
--- a/dbms/include/DB/Interpreters/Aggregator.h
+++ b/dbms/include/DB/Interpreters/Aggregator.h
@@ -48,7 +48,7 @@ typedef std::vector<AggregateDescription> AggregateDescriptions;
   */
 typedef AggregateDataPtr AggregatedDataWithoutKey;
 typedef HashMap<UInt64, AggregateDataPtr> AggregatedDataWithUInt64Key;
-typedef HashMap<StringRef, AggregateDataPtr> AggregatedDataWithStringKey;
+typedef HashMapWithSavedHash<StringRef, AggregateDataPtr> AggregatedDataWithStringKey;
 typedef HashMap<UInt128, AggregateDataPtr, UInt128Hash> AggregatedDataWithKeys128;
 typedef HashMap<UInt128, std::pair<StringRef*, AggregateDataPtr>, UInt128TrivialHash> AggregatedDataHashed;
 
diff --git a/dbms/include/DB/Interpreters/Set.h b/dbms/include/DB/Interpreters/Set.h
index 384fde072ed..91393c32d80 100644
--- a/dbms/include/DB/Interpreters/Set.h
+++ b/dbms/include/DB/Interpreters/Set.h
@@ -94,7 +94,7 @@ private:
 	  *  одного или нескольких столбцов значений множеству.
 	  */
 	typedef HashSet<UInt64> SetUInt64;
-	typedef HashSet<StringRef> SetString;
+	typedef HashSetWithSavedHash<StringRef> SetString;
 	typedef HashSet<UInt128, UInt128Hash> SetHashed;
 
 	BlockInputStreamPtr source;