diff --git a/reconstruct/ast.py b/reconstruct/ast.py
index a260ccb..e1430f3 100644
--- a/reconstruct/ast.py
+++ b/reconstruct/ast.py
@@ -596,11 +596,14 @@ class groupby_c(ast_node):
                  col_names : List[str], col_types : List[Types], col_tovec : List[bool]):
         tovec_columns = set()
         for i, c in enumerate(col_names):
-            self.context.emitc(f'{c}.reserve({self.group}.size());')
             if col_tovec[i]: # and type(col_types[i]) is VectorT:
+                self.context.emitc(f'{c}.resize({self.group}.size());')
                 typename : Types = col_types[i] # .inner_type
                 self.context.emitc(f'auto buf_{c} = static_cast<{typename.cname} *>(calloc({self.total_sz}, sizeof({typename.cname})));')
                 tovec_columns.add(c)
+            else:
+                self.context.emitc(f'{c}.reserve({self.group}.size());')
+                
         self.arr_len = 'arrlen_' + base62uuid(3)
         self.arr_values = 'arrvals_' + base62uuid(3)
         
diff --git a/server/libaquery.cpp b/server/libaquery.cpp
index 60e4b81..500640d 100644
--- a/server/libaquery.cpp
+++ b/server/libaquery.cpp
@@ -615,3 +615,26 @@ aq_to_chars<std::string_view>(void* value, char* buffer){
 	return buffer + src.size();
 }
 
+// Defined in vector_type.h
+template <>
+vector_type<std::string_view>::vector_type(const char** container, uint32_t len, 
+		typename std::enable_if_t<true>*) noexcept
+{
+	size = capacity = len;
+	this->container = static_cast<std::string_view*>(
+		malloc(sizeof(std::string_view) * len));
+	for(uint32_t i = 0; i < len; ++i){
+		this->container[i] = container[i];
+	}
+}
+
+template<>
+vector_type<std::string_view>::vector_type(const uint32_t size, void* data) : 
+	size(size), capacity(0) {
+	this->container = static_cast<std::string_view*>(
+		malloc(sizeof(std::string_view) * size));
+	for(uint32_t i = 0; i < size; ++i){
+		this->container[i] = ((const char**)data)[i];
+	}
+	//std::cout<<size << container[1];
+}
diff --git a/server/table.h b/server/table.h
index 6f7dfdf..b32f4b8 100644
--- a/server/table.h
+++ b/server/table.h
@@ -913,8 +913,8 @@ VT<bool> operator >(const T2& lhs, const VT<T1>& rhs) {
 #define _AQ_OP_(x) __AQ_OP__##x
 #define __AQ_OP__add +
 #define __AQ_OP__minus -
-#define __AQ_OP__div *
-#define __AQ_OP__mul /
+#define __AQ_OP__mul *
+#define __AQ_OP__div /
 #define __AQ_OP__and &
 #define __AQ_OP__or |
 #define __AQ_OP__xor ^
@@ -934,8 +934,8 @@ void aqop_##x (const VT<T1>& lhs, const VT<T2>& rhs, Ret& ret){\
 
 __D_AQOP(add)
 __D_AQOP(minus)
-__D_AQOP(div)
 __D_AQOP(mul)
+__D_AQOP(div)
 __D_AQOP(and)
 __D_AQOP(or)
 __D_AQOP(xor)
diff --git a/server/table_ext_monetdb.hpp b/server/table_ext_monetdb.hpp
index 3c93c3f..65d34e5 100644
--- a/server/table_ext_monetdb.hpp
+++ b/server/table_ext_monetdb.hpp
@@ -28,7 +28,7 @@ inline constexpr monetdbe_types AQType_2_monetdbe[] = {
 #else	
 		monetdbe_int64_t,
 #endif
-		monetdbe_timestamp, monetdbe_int64_t, monetdbe_int64_t
+		monetdbe_timestamp, monetdbe_int8_t, monetdbe_str, monetdbe_int64_t, monetdbe_int64_t
 };
 
 template<class ...Ts>
@@ -75,12 +75,14 @@ void TableInfo<Ts ...>::monetdb_append_table(void* srv, const char* alt_name) {
 			auto err = monetdbe_append(*((monetdbe_database*)server->server), "sys", alt_name, monetdbe_cols, sizeof...(Ts));
 			if (err)
 				puts(err);
-			return;
+			goto finialize;
 		}
 	}
-	// for(uint32_t i = 0; i < n_vecs; ++i) 
-	// 		free(gc_vecs[i]);
 	puts("Error! Empty table.");
+
+finialize:	
+	for(uint32_t i = 0; i < cnt; ++i) 
+		GC::gc_handle->reg(gc_vecs[i]);
 }
 
 
@@ -92,6 +94,16 @@ void* ColRef<Type>::monetdb_get_col(void** gc_vecs, uint32_t& cnt) {
 	col->type = aq_type;
 	col->count = this->size;
 	col->data = this->container;
+
+	if constexpr(std::is_same_v<Type, std::string_view>) {
+		auto _data = static_cast<const char **>(
+			malloc(sizeof(const char *) * this->size));
+		for(uint32_t i = 0; i < this->size; ++i){
+			_data[i] = this->container[i].data();
+		}
+		col->data = _data;
+		gc_vecs[cnt++] = _data;
+	}
 	col->name = const_cast<char*>(this->name);
 	// auto arr = (types::timestamp_t*) malloc (sizeof(types::timestamp_t)* this->size);
 	// if constexpr (is_vector_type<Type>){
@@ -102,5 +114,4 @@ void* ColRef<Type>::monetdb_get_col(void** gc_vecs, uint32_t& cnt) {
 	// }
 	return col;
 }
-
 #endif
diff --git a/server/types.h b/server/types.h
index f9ad100..921eabd 100644
--- a/server/types.h
+++ b/server/types.h
@@ -393,9 +393,9 @@ template <class ...T1s, class ...T2s, template <class...> class T1>
 struct same_class_impl<T1<T1s...>, T1<T2s...>> : std::true_type {};
 
 template <class T1, class T2>
-bool same_class = same_class_impl<T1, T2>::value;
+constexpr bool same_class = same_class_impl<T1, T2>::value;
 template <class T1, template <class...> class T2>
-bool instance_of = instance_of_impl<T1, T2>::value;
+constexpr bool instance_of = instance_of_impl<T1, T2>::value;
 
 template <class lT, template <typename ...> class rT>
 using transTypes = typename transTypes_s<lT, rT>::type;
diff --git a/server/vector_type.hpp b/server/vector_type.hpp
index caa0f33..6b21ff9 100644
--- a/server/vector_type.hpp
+++ b/server/vector_type.hpp
@@ -61,7 +61,9 @@ public:
 			[[likely]]
 			container = (_Ty*)GC::scratch_space->alloc(size * sizeof(_Ty));
 		}
-		container = (_Ty*)malloc(size * sizeof(_Ty));
+		else{
+			container = (_Ty*)malloc(size * sizeof(_Ty));
+		}
 		// TODO: calloc for objects. 
 	}
 	explicit constexpr vector_type(std::initializer_list<_Ty> _l) {
@@ -74,7 +76,7 @@ public:
 	}
 	constexpr vector_type() noexcept : size(0), capacity(0), container(0) {};
 	constexpr vector_type(_Ty* container, uint32_t len) noexcept : size(len), capacity(0), container(container) {};
-	constexpr vector_type(const char** container, uint32_t len, 
+	vector_type(const char** container, uint32_t len, 
 		typename std::enable_if_t<!std::is_same_v<_Ty, const char*>>* = nullptr) noexcept = delete;
 	constexpr explicit vector_type(const vector_type<_Ty>& vt) noexcept : capacity(0) {
 		_copy(vt);
@@ -90,7 +92,7 @@ public:
 		// out(10);
 	};
 	// size >= capacity ==> readonly vector
-	constexpr vector_type(const uint32_t size, void* data) : 
+	vector_type(const uint32_t size, void* data) : 
 		size(size), capacity(0), container(static_cast<_Ty*>(data)) {}
 
 	void init_from(const uint32_t size, void* data) {
@@ -341,7 +343,8 @@ public:
 	vector_type<_Ty> getRef() { return vector_type<_Ty>(container, size); }
 	~vector_type() {
 		if (capacity > 0) GC::gc_handle->reg(container, sizeof(_Ty) * capacity);//free(container);
-		container = 0; size = capacity = 0;
+		container = nullptr; 
+		size = capacity = 0;
 	}
 #define Compare(_op) \
 	template<typename T> \
@@ -404,28 +407,6 @@ public:
 	_Make_Ops(Opseq)
 };
 
-template <>
-constexpr vector_type<std::string_view>::vector_type(const char** container, uint32_t len, 
-		typename std::enable_if_t<true>*) noexcept
-{
-	size = capacity = len;
-	this->container = static_cast<std::string_view*>(
-		malloc(sizeof(std::string_view) * len));
-	for(uint32_t i = 0; i < len; ++i){
-		this->container[i] = container[i];
-	}
-}
-
-template<>
-constexpr vector_type<std::string_view>::vector_type(const uint32_t size, void* data) : 
-	size(size), capacity(0) {
-	this->container = static_cast<std::string_view*>(
-		malloc(sizeof(std::string_view) * size));
-	for(uint32_t i = 0; i < size; ++i){
-		this->container[i] = ((const char**)data)[i];
-	}
-	//std::cout<<size << container[1];
-}
 
 // template<>
 // void vector_type<std::string_view>::init_from(const uint32_t size, void* data) {
@@ -527,4 +508,10 @@ public:
 	}
 };
 
+template<>
+vector_type<std::string_view>::vector_type(const uint32_t size, void* data);
+template <>
+vector_type<std::string_view>::vector_type(const char** container, uint32_t len, 
+		typename std::enable_if_t<true>*) noexcept;
+
 #endif