diff --git a/clickhouse/columns/date.cpp b/clickhouse/columns/date.cpp
index af3ccb20..c3476c7f 100644
--- a/clickhouse/columns/date.cpp
+++ b/clickhouse/columns/date.cpp
@@ -43,8 +43,8 @@ void ColumnDate::Append(ColumnRef column) {
     }
 }
 
-std::vector<uint16_t> &ColumnDate::GetRawVector() {
-    return data_->GetRawVector();
+std::vector<uint16_t>& ColumnDate::GetWritableData() {
+    return data_->GetWritableData();
 }
 
 void ColumnDate::Reserve(size_t new_cap) {
@@ -122,8 +122,8 @@ void ColumnDate32::Append(ColumnRef column) {
     }
 }
 
-std::vector<int32_t> & ColumnDate32::GetRawVector() {
-    return data_->GetRawVector();
+std::vector<int32_t>& ColumnDate32::GetWritableData() {
+    return data_->GetWritableData();
 }
 
 void ColumnDate32::Reserve(size_t new_cap) {
@@ -220,8 +220,8 @@ void ColumnDateTime::Append(ColumnRef column) {
     }
 }
 
-std::vector<uint32_t> & ColumnDateTime::GetRawVector() {
-    return data_->GetRawVector();
+std::vector<uint32_t>& ColumnDateTime::GetWritableData() {
+    return data_->GetWritableData();
 }
 
 void ColumnDateTime::Reserve(size_t new_cap) {
diff --git a/clickhouse/columns/date.h b/clickhouse/columns/date.h
index 0faca1ec..c6e32234 100644
--- a/clickhouse/columns/date.h
+++ b/clickhouse/columns/date.h
@@ -32,7 +32,7 @@ class ColumnDate : public Column {
     void Append(ColumnRef column) override;
 
     /// Get Raw Vector Contents
-    std::vector<uint16_t> & GetRawVector();
+    std::vector<uint16_t>& GetWritableData();
 
     /// Increase the capacity of the column
     void Reserve(size_t new_cap);
@@ -89,7 +89,7 @@ class ColumnDate32 : public Column {
     int32_t RawAt(size_t n) const;
 
     /// Get Raw Vector Contents
-    std::vector<int32_t> & GetRawVector();
+    std::vector<int32_t>& GetWritableData();
 
     /// Increase the capacity of the column
     void Reserve(size_t new_cap);
@@ -146,7 +146,7 @@ class ColumnDateTime : public Column {
     std::string Timezone() const;
 
     /// Get Raw Vector Contents
-    std::vector<uint32_t> & GetRawVector();
+    std::vector<uint32_t>& GetWritableData();
 
     /// Increase the capacity of the column
     void Reserve(size_t new_cap);
diff --git a/clickhouse/columns/numeric.cpp b/clickhouse/columns/numeric.cpp
index 57a32dd0..1c611c79 100644
--- a/clickhouse/columns/numeric.cpp
+++ b/clickhouse/columns/numeric.cpp
@@ -39,7 +39,7 @@ void ColumnVector<T>::Erase(size_t pos, size_t count) {
 }
 
 template <typename T>
-std::vector<T> & ColumnVector<T>::GetRawVector() {
+std::vector<T>& ColumnVector<T>::GetWritableData() {
     return data_;
 }
 
diff --git a/clickhouse/columns/numeric.h b/clickhouse/columns/numeric.h
index d3523614..1cbcca9c 100644
--- a/clickhouse/columns/numeric.h
+++ b/clickhouse/columns/numeric.h
@@ -31,7 +31,7 @@ class ColumnVector : public Column {
     void Erase(size_t pos, size_t count = 1);
 
     /// Get Raw Vector Contents
-    std::vector<T> & GetRawVector();
+    std::vector<T>& GetWritableData();
 
     /// Increase the capacity of the column
     void Reserve(size_t new_cap);
diff --git a/ut/Column_ut.cpp b/ut/Column_ut.cpp
index 6e5668e6..9eb3c7cf 100644
--- a/ut/Column_ut.cpp
+++ b/ut/Column_ut.cpp
@@ -16,10 +16,14 @@
 #include <clickhouse/client.h>
 
 #include <gtest/gtest.h>
+#include <algorithm>
 #include <initializer_list>
 #include <memory>
 #include <type_traits>
 
+#include "gtest/internal/gtest-internal.h"
+#include "ut/utils_comparison.h"
+#include "ut/utils_meta.h"
 #include "utils.h"
 #include "roundtrip_column.h"
 #include "value_generators.h"
@@ -364,6 +368,82 @@ TYPED_TEST(GenericColumnTest, Swap) {
     EXPECT_TRUE(CompareRecursive(values, *column_B));
 }
 
+// GTEST_SKIP for debug builds to draw attention of developer
+#if !defined(NDEBUG)
+#define COLUMN_DOESNT_IMPLEMENT(comment) GTEST_SKIP() << this->MakeColumn()->GetType().GetName() << " doesn't implement " << comment;
+#else
+#define COLUMN_DOESNT_IMPLEMENT(comment) GTEST_SUCCEED() << this->MakeColumn()->GetType().GetName() << " doesn't implement " << comment;
+#endif
+
+TYPED_TEST(GenericColumnTest, ReserveAndCapacity) {
+    if constexpr (
+        // TODO(venemkov): test that ColumnType has Reserve() and Capacity() methods
+        is_one_of_v<typename TestFixture::ColumnType,
+            // Only types that support Reserve() and Capacity() methods
+            ColumnUInt8,
+            ColumnUInt16,
+            ColumnUInt32,
+            ColumnUInt64,
+            ColumnInt8,
+            ColumnInt16,
+            ColumnInt32,
+            ColumnInt64,
+            ColumnInt128,
+            ColumnFloat32,
+            ColumnFloat64,
+            ColumnDate,
+            ColumnDate32,
+            ColumnDateTime>) {
+
+        auto column = this->MakeColumn();
+        EXPECT_EQ(0u, column->Capacity());
+        EXPECT_NO_THROW(column->Reserve(100u));
+        EXPECT_EQ(100u, column->Capacity());
+        EXPECT_EQ(0u, column->Size());
+    }
+    else {
+        COLUMN_DOESNT_IMPLEMENT("method Reserve() and Capacity()");
+    }
+}
+
+
+TYPED_TEST(GenericColumnTest, GetWritableData) {
+    if constexpr (
+        // TODO(venemkov): test that ColumnType has GetWritableData() method
+        is_one_of_v<typename TestFixture::ColumnType,
+        // Only types that support GetWritableData() method
+                    ColumnUInt8,
+                    ColumnUInt16,
+                    ColumnUInt32,
+                    ColumnUInt64,
+                    ColumnInt8,
+                    ColumnInt16,
+                    ColumnInt32,
+                    ColumnInt64,
+                    ColumnInt128,
+                    ColumnFloat32,
+                    ColumnFloat64,
+                    ColumnDate,
+                    ColumnDate32,
+                    ColumnDateTime>) {
+        auto [column, values] = this->MakeColumnWithValues(111);
+        // Do conversion from time_t to internal representation, similar to what ColumnDate and ColumnDate32 do
+        if constexpr (is_one_of_v<typename TestFixture::ColumnType,
+                    ColumnDate,
+                    ColumnDate32>) {
+            std::for_each(values.begin(), values.end(), [](auto & value) {
+                value /= 86400;
+            });
+        }
+
+        EXPECT_TRUE(CompareRecursive(values, column->GetWritableData()));
+    }
+    else {
+        COLUMN_DOESNT_IMPLEMENT("method GetWritableData()");
+    }
+}
+
+
 TYPED_TEST(GenericColumnTest, LoadAndSave) {
     auto [column_A, values] = this->MakeColumnWithValues(100);
 
diff --git a/ut/columns_ut.cpp b/ut/columns_ut.cpp
index 0de73231..aaad5f26 100644
--- a/ut/columns_ut.cpp
+++ b/ut/columns_ut.cpp
@@ -965,93 +965,3 @@ TEST(ColumnsCase, ColumnMapT_Wrap) {
     EXPECT_EQ("123", map_view.At(1));
     EXPECT_EQ("abc", map_view.At(2));
 }
-
-TEST(ColumnsCase, ReservedAndCapacity) {
-    std::vector<std::shared_ptr<Column>> columns;
-
-    #define RaC_TEST_CASE(test_id_in, column_type) \
-        case test_id_in: { \
-            columns.push_back(std::make_shared<column_type>()); \
-            auto column = std::static_pointer_cast<column_type>(columns[test_id_in]); \
-            column->Reserve(100u); \
-            ASSERT_EQ(column->Capacity(), 100u); \
-            ASSERT_EQ(columns[test_id_in]->Size(), 0u); \
-            break; \
-        }
-
-    for (uint8_t rac_test_id = 0; rac_test_id < 14; ++rac_test_id) {
-        switch (rac_test_id) {
-            RaC_TEST_CASE( 0, ColumnUInt8);
-            RaC_TEST_CASE( 1, ColumnUInt16);
-            RaC_TEST_CASE( 2, ColumnUInt32);
-            RaC_TEST_CASE( 3, ColumnUInt64);
-            RaC_TEST_CASE( 4, ColumnInt8);
-            RaC_TEST_CASE( 5, ColumnInt16);
-            RaC_TEST_CASE( 6, ColumnInt32);
-            RaC_TEST_CASE( 7, ColumnInt64);
-            RaC_TEST_CASE( 8, ColumnInt128);
-            RaC_TEST_CASE( 9, ColumnFloat32);
-            RaC_TEST_CASE(10, ColumnFloat64);
-            RaC_TEST_CASE(11, ColumnDate);
-            RaC_TEST_CASE(12, ColumnDate32);
-            RaC_TEST_CASE(13, ColumnDateTime);
-            default: {
-                EXPECT_NE(0, 0);
-                break;
-            }
-        }
-    }
-}
-
-TEST(ColumnsCase, RawVector) {
-    std::vector<std::shared_ptr<Column>> columns;
-
-    #define RV_TEST_CASE(test_id_in, column_type) \
-        case test_id_in: { \
-            columns.push_back(std::make_shared<column_type>()); \
-            auto column = std::static_pointer_cast<column_type>(columns[test_id_in]); \
-            column->Append(10u); \
-            column->Append(20u); \
-            ASSERT_EQ(columns[test_id_in]->Size(), 2u); \
-            auto column_v = column->GetRawVector(); \
-            ASSERT_EQ(static_cast<uint32_t>(column_v[0]), 10u); \
-            ASSERT_EQ(static_cast<uint32_t>(column_v[1]), 20u); \
-            break; \
-        }
-
-    #define RV_TEST_CASE_D(test_id_in, column_type) \
-        case test_id_in: { \
-            columns.push_back(std::make_shared<column_type>()); \
-            auto column = std::static_pointer_cast<column_type>(columns[test_id_in]); \
-            column->AppendRaw(10u); \
-            column->AppendRaw(20u); \
-            ASSERT_EQ(columns[test_id_in]->Size(), 2u); \
-            auto column_v = column->GetRawVector(); \
-            ASSERT_EQ(static_cast<uint32_t>(column_v[0]), 10u); \
-            ASSERT_EQ(static_cast<uint32_t>(column_v[1]), 20u); \
-            break; \
-        }
-
-    for (uint8_t rv_test_id = 0; rv_test_id < 14; ++rv_test_id) {
-        switch (rv_test_id) {
-            RV_TEST_CASE(    0, ColumnUInt8);
-            RV_TEST_CASE(    1, ColumnUInt16);
-            RV_TEST_CASE(    2, ColumnUInt32);
-            RV_TEST_CASE(    3, ColumnUInt64);
-            RV_TEST_CASE(    4, ColumnInt8);
-            RV_TEST_CASE(    5, ColumnInt16);
-            RV_TEST_CASE(    6, ColumnInt32);
-            RV_TEST_CASE(    7, ColumnInt64);
-            RV_TEST_CASE(    8, ColumnInt128);
-            RV_TEST_CASE(    9, ColumnFloat32);
-            RV_TEST_CASE(   10, ColumnFloat64);
-            RV_TEST_CASE_D( 11, ColumnDate);
-            RV_TEST_CASE_D( 12, ColumnDate32);
-            RV_TEST_CASE_D( 13, ColumnDateTime);
-            default: {
-                EXPECT_NE(0, 0);
-                break;
-            }
-        }
-    }
-}
diff --git a/ut/utils.h b/ut/utils.h
index b4b8e92d..99216743 100644
--- a/ut/utils.h
+++ b/ut/utils.h
@@ -7,6 +7,7 @@
 #include "utils_meta.h"
 #include "utils_comparison.h"
 
+#include <iterator>
 #include <optional>
 #include <ostream>
 #include <ratio>
@@ -181,7 +182,7 @@ std::ostream& operator<<(std::ostream & ostr, const PrintContainer<T>& print_con
         }
     }
 
-    return ostr << "]";
+    return ostr << "] (" << std::size(container) << " items)";
 }
 
 inline uint64_t versionNumber(
diff --git a/ut/utils_meta.h b/ut/utils_meta.h
index 3c50da4e..6cf55d2e 100644
--- a/ut/utils_meta.h
+++ b/ut/utils_meta.h
@@ -51,3 +51,18 @@ struct is_instantiation_of< Template, Template<Args...> > : std::true_type {};
 
 template <typename T>
 inline constexpr bool is_string_v = std::is_same_v<std::string, std::decay_t<T>> || std::is_same_v<std::string_view, std::decay_t<T>>;
+
+// https://stackoverflow.com/a/34111095
+template <typename...>
+struct is_one_of {
+    static constexpr bool value = false;
+};
+
+template <typename F, typename S, typename... T>
+struct is_one_of<F, S, T...> {
+    static constexpr bool value =
+        std::is_same<F, S>::value || is_one_of<F, T...>::value;
+};
+
+template <typename F, typename S, typename... T>
+inline constexpr bool is_one_of_v = is_one_of<F, S, T...>::value;