merge

2024-12-17 11:52:27 +00:00 · 2018-04-02 18:33:53 +03:00 · 2018-04-02 18:33:53 +03:00 · 284a9eacc4
commit 284a9eacc4
parent 1fe6f7ba69 2b08e8208f
421 changed files with 5965 additions and 3531 deletions
--- a/.travis.yml
+++ b/.travis.yml
@ -13,7 +13,7 @@ matrix:
 #        apt:
 #          sources:
 #            - ubuntu-toolchain-r-test
-#          packages: [ g++-7,            libicu-dev, libreadline-dev, libmysqlclient-dev, unixodbc-dev, libltdl-dev, libssl-dev, libboost-dev, zlib1g-dev, libdouble-conversion-dev, libzookeeper-mt-dev, libsparsehash-dev, librdkafka-dev, libcapnp-dev, libsparsehash-dev, libgoogle-perftools-dev, bash, expect, python, python-lxml, python-termcolor, curl, perl, sudo ]
+#          packages: [ g++-7,            libicu-dev, libreadline-dev, libmysqlclient-dev, unixodbc-dev, libltdl-dev, libssl-dev, libboost-dev, zlib1g-dev, libdouble-conversion-dev, libzookeeper-mt-dev, libsparsehash-dev, librdkafka-dev, libcapnp-dev, libsparsehash-dev, libgoogle-perftools-dev, bash, expect, python, python-lxml, python-termcolor, curl, perl, sudo, openssl ]
 #
 #      env:
 #        - MATRIX_EVAL="export CC=gcc-7 && export CXX=g++-7"
@ -36,7 +36,7 @@ matrix:
          sources:
            - ubuntu-toolchain-r-test
            - llvm-toolchain-trusty-5.0
-          packages: [ g++-7, clang-5.0, lld-5.0, libicu-dev, libreadline-dev, libmysqlclient-dev, unixodbc-dev, libltdl-dev, libssl-dev, libboost-dev, zlib1g-dev, libdouble-conversion-dev, libzookeeper-mt-dev, libsparsehash-dev, librdkafka-dev, libcapnp-dev, libsparsehash-dev, libgoogle-perftools-dev, bash, expect, python, python-lxml, python-termcolor, curl, perl, sudo ]
+          packages: [ g++-7, clang-5.0, lld-5.0, libicu-dev, libreadline-dev, libmysqlclient-dev, unixodbc-dev, libltdl-dev, libssl-dev, libboost-dev, zlib1g-dev, libdouble-conversion-dev, libzookeeper-mt-dev, libsparsehash-dev, librdkafka-dev, libcapnp-dev, libsparsehash-dev, libgoogle-perftools-dev, bash, expect, python, python-lxml, python-termcolor, curl, perl, sudo, openssl]

      env:
        - MATRIX_EVAL="export CC=clang-5.0 && export CXX=clang++-5.0"
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@ -1,4 +1,31 @@
-# ClickHouse 1.1.54356 Release Candidate, 2018-03-06
+# ClickHouse 1.1.54370 Release Candidate, 2018-03-16
+
+## New features:
+
+* Added the `system.macros` table and auto updating of macros when the config file is changed.
+* Added the `SYSTEM RELOAD CONFIG` query.
+* Added the `maxIntersections(left_col, right_col)` aggregate function, which returns the maximum number of simultaneously intersecting intervals `[left; right]`. The `maxIntersectionsPosition(left, right)` function returns the beginning of the "maximum" interval. ([Michael Furmur](https://github.com/yandex/ClickHouse/pull/2012)).
+
+## Improvements:
+
+* When inserting data in a `Replicated` table, fewer requests are made to `ZooKeeper` (and most of the user-level errors have disappeared from the `ZooKeeper` log).
+* Added the ability to create aliases for sets. Example: `WITH (1, 2, 3) AS set SELECT number IN set FROM system.numbers LIMIT 10`.
+
+## Bug fixes:
+
+* Fixed the `Illegal PREWHERE` error when reading from `Merge` tables over `Distributed` tables.
+* Added fixes that allow you to run `clickhouse-server` in IPv4-only Docker containers.
+* Fixed a race condition when reading from system `system.parts_columns` tables.
+* Removed double buffering during a synchronous insert to a `Distributed` table, which could have caused the connection to timeout.
+* Fixed a bug that caused excessively long waits for an unavailable replica before beginning a `SELECT` query.
+* Fixed incorrect dates in the `system.parts` table.
+* Fixed a bug that made it impossible to insert data in a `Replicated` table if `chroot` was non-empty in the configuration of the `ZooKeeper` cluster.
+* Fixed the vertical merging algorithm for an empty `ORDER BY` table.
+* Restored the ability to use dictionaries in queries to remote tables, even if these dictionaries are not present on the requestor server. This functionality was lost in release 1.1.54362.
+* Restored the behavior for queries like `SELECT * FROM remote('server2', default.table) WHERE col IN (SELECT col2 FROM default.table)` when the right side argument of the `IN` should use a remote `default.table` instead of a local one. This behavior was broken in version 1.1.54358.
+* Removed extraneous error-level logging of `Not found column ... in block`.
+
+# ClickHouse release 1.1.54356, 2018-03-06

 ## New features:

--- a/CHANGELOG_RU.md
+++ b/CHANGELOG_RU.md
@ -1,4 +1,32 @@
-# ClickHouse 1.1.54362 Release Candidate, 2018-03-11
+# ClickHouse 1.1.54370 Release Candidate, 2018-03-16
+
+## Новые возможности:
+
+* Добавлена системная таблица `system.macros` и автоматическое обновление макросов при изменении конфигурационного файла.
+* Добавлен запрос `SYSTEM RELOAD CONFIG`.
+* Добавлена агрегатная функция `maxIntersections(left_col, right_col)`, возвращающая максимальное количество одновременно пересекающихся интервалов `[left; right]`. Функция `maxIntersectionsPosition(left, right)` возвращает начало такого "максимального" интервала. ([Michael Furmur](https://github.com/yandex/ClickHouse/pull/2012)).
+
+## Улучшения:
+
+* При вставке данных в `Replicated`-таблицу делается меньше обращений к `ZooKeeper` (также из лога `ZooKeeper` исчезло большинство user-level ошибок).
+* Добавлена возможность создавать алиасы для множеств. Пример: `WITH (1, 2, 3) AS set SELECT number IN set FROM system.numbers LIMIT 10`.
+
+## Исправление ошибок:
+
+* Исправлена ошибка `Illegal PREWHERE` при чтении из Merge-таблицы над `Distributed`-таблицами.
+* Добавлены исправления, позволяющие запускать clickhouse-server в IPv4-only docker-контейнерах.
+* Исправлен race condition при чтении из системной таблицы `system.parts_columns`
+* Убрана двойная буферизация при синхронной вставке в `Distributed`-таблицу, которая могла приводить к timeout-ам соединений.
+* Исправлена ошибка, вызывающая чрезмерно долгое ожидание недоступной реплики перед началом выполнения `SELECT`.
+* Исправлено некорректное отображение дат в таблице `system.parts`.
+* Исправлена ошибка, приводящая к невозможности вставить данные в `Replicated`-таблицу, если в конфигурации кластера `ZooKeeper` задан непустой `chroot`.
+* Исправлен алгоритм вертикального мержа при пустом ключе `ORDER BY` таблицы.
+* Возвращена возможность использовать словари в запросах к удаленным таблицам, даже если этих словарей нет на сервере-инициаторе. Данная функциональность была потеряна в версии 1.1.54362.
+* Восстановлено поведение, при котором в запросах типа `SELECT * FROM remote('server2', default.table) WHERE col IN (SELECT col2 FROM default.table)` в правой части `IN` должна использоваться удаленная таблица `default.table`, а не локальная. данное поведение было нарушено в версии 1.1.54358.
+* Устранено ненужное Error-level логирование `Not found column ... in block`.
+
+
+# Релиз ClickHouse 1.1.54362, 2018-03-11

 ## Новые возможности:

--- a/cmake/find_poco.cmake
+++ b/cmake/find_poco.cmake
@ -49,7 +49,8 @@ elseif (NOT MISSING_INTERNAL_POCO_LIBRARY)
        set (Poco_DataODBC_INCLUDE_DIRS "${ClickHouse_SOURCE_DIR}/contrib/poco/Data/ODBC/include/")
    endif ()

-    if (OPENSSL_FOUND)
+    # TODO! fix internal ssl
+    if (OPENSSL_FOUND AND NOT USE_INTERNAL_SSL_LIBRARY)
        set (Poco_NetSSL_FOUND 1)
        set (Poco_NetSSL_LIBRARY PocoNetSSL)
        set (Poco_Crypto_LIBRARY PocoCrypto)
--- a/contrib/CMakeLists.txt
+++ b/contrib/CMakeLists.txt
@ -26,7 +26,7 @@ if (USE_INTERNAL_DOUBLE_CONVERSION_LIBRARY)
 endif ()

 if (USE_INTERNAL_ZOOKEEPER_LIBRARY)
-    add_subdirectory (zookeeper/src/c)
+    add_subdirectory (zookeeper-cmake)
 endif ()

 if (USE_INTERNAL_CITYHASH_LIBRARY)
@ -100,13 +100,17 @@ if (USE_INTERNAL_RDKAFKA_LIBRARY)
    mark_as_advanced (ZLIB_INCLUDE_DIR)

    if (USE_INTERNAL_SSL_LIBRARY)
-        add_library(bundled-ssl ALIAS ${OPENSSL_SSL_LIBRARY})
-        set (WITH_BUNDLED_SSL 1)
+        if (MAKE_STATIC_LIBRARIES)
+            add_library(bundled-ssl ALIAS ${OPENSSL_SSL_LIBRARY})
+            set (WITH_BUNDLED_SSL 1 CACHE INTERNAL "")
+        else ()
+            set (WITH_SSL 0 CACHE INTERNAL "")
+        endif ()
    endif ()

    add_subdirectory (librdkafka)

-    if (USE_INTERNAL_SSL_LIBRARY)
+    if (USE_INTERNAL_SSL_LIBRARY AND MAKE_STATIC_LIBRARIES)
        target_include_directories(rdkafka PRIVATE BEFORE ${OPENSSL_INCLUDE_DIR})
    endif ()
    target_include_directories(rdkafka PRIVATE BEFORE ${ZLIB_INCLUDE_DIR})
@ -127,16 +131,18 @@ endif ()


 if (USE_INTERNAL_POCO_LIBRARY)
-    set (ALLOW_DUPLICATE_CUSTOM_TARGETS 1)
    set (save_CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
    set (save_CMAKE_C_FLAGS ${CMAKE_C_FLAGS})
    set (_save ${ENABLE_TESTS})
    set (ENABLE_TESTS 0)
    set (CMAKE_DISABLE_FIND_PACKAGE_ZLIB 1)
    if (USE_INTERNAL_SSL_LIBRARY)
-        set (DISABLE_INTERNAL_OPENSSL 1)
-        set (ENABLE_NETSSL 0) # TODO!
-        set (ENABLE_CRYPTO 0) # TODO!
+        set (DISABLE_INTERNAL_OPENSSL 1 CACHE INTERNAL "")
+        set (ENABLE_NETSSL 0 CACHE INTERNAL "") # TODO!
+        set (ENABLE_CRYPTO 0 CACHE INTERNAL "") # TODO!
+    endif ()
+    if (MSVC)
+        set (ENABLE_DATA_ODBC 0 CACHE INTERNAL "") # TODO (build fail)
    endif ()
    add_subdirectory (poco)
    unset (CMAKE_DISABLE_FIND_PACKAGE_ZLIB)
--- a/contrib/boost
+++ b/contrib/boost
@ -1 +1 @@
-Subproject commit eb5943711e88d1008583e6ae3720a5489313d02e
+Subproject commit 5121cc9d0375c7b81b24b6087a51684e6cd62ded
--- a/contrib/libcityhash/src/config.h
+++ b/contrib/libcityhash/src/config.h
@ -5,7 +5,11 @@
 /* #undef AC_APPLE_UNIVERSAL_BUILD */

 /* Define to 1 if the compiler supports __builtin_expect. */
+#if _MSC_VER
+#define HAVE_BUILTIN_EXPECT 0
+#else
 #define HAVE_BUILTIN_EXPECT 1
+#endif

 /* Define to 1 if you have the <dlfcn.h> header file. */
 #define HAVE_DLFCN_H 1
--- a/contrib/libfarmhash/CMakeLists.txt
+++ b/contrib/libfarmhash/CMakeLists.txt
@ -2,4 +2,8 @@ add_library(farmhash
 	farmhash.cc
 	farmhash.h)

+if (MSVC)
+    target_compile_definitions (farmhash PRIVATE FARMHASH_NO_BUILTIN_EXPECT=1)
+endif ()
+
 target_include_directories (farmhash PUBLIC ${CMAKE_CURRENT_BINARY_DIR})
--- a/contrib/libtcmalloc/src/config.h
+++ b/contrib/libtcmalloc/src/config.h
@ -13,7 +13,11 @@
 /* #undef ENABLE_SIZED_DELETE */

 /* Define to 1 if compiler supports __builtin_expect */
+#if _MSC_VER
+#define HAVE_BUILTIN_EXPECT 0
+#else
 #define HAVE_BUILTIN_EXPECT 1
+#endif

 /* Define to 1 if compiler supports __builtin_stack_pointer */
 /* #undef HAVE_BUILTIN_STACK_POINTER */
--- a/contrib/poco
+++ b/contrib/poco
@ -1 +1 @@
-Subproject commit 8238852d7ab2a4abdf87adff233b3b83686f4fe4
+Subproject commit a107b0c9cee109fe0abfbf509df3c78a1e0c05fa
--- a/contrib/zookeeper-cmake/CMakeLists.txt
+++ b/contrib/zookeeper-cmake/CMakeLists.txt
@ -0,0 +1,200 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+cmake_minimum_required(VERSION 3.0)
+
+# Modified version of CMakeLists.txt for ClickHouse. Doesn't link the library to libm.
+# Otherwise we have extra dependency when compiling with the most fresh libc version.
+# How to check:
+# readelf -s ./clickhouse | grep -F 2.23
+
+SET(LIBRARY_DIR ${ClickHouse_SOURCE_DIR}/contrib/zookeeper/src/c)
+
+project(zookeeper VERSION 3.5.3)
+set(email user@zookeeper.apache.org)
+set(description "zookeeper C client")
+
+# general options
+if(UNIX)
+  add_compile_options(-Wall -fPIC)
+elseif(WIN32)
+  add_compile_options(/W3)
+endif()
+add_definitions(-DUSE_STATIC_LIB)
+
+# TODO: Enable /WX and /W4 on Windows. Currently there are ~1000 warnings.
+# TODO: Add Solaris support.
+# TODO: Add a shared library option.
+# TODO: Specify symbols to export.
+# TODO: Generate doxygen documentation.
+
+# Sync API option
+option(WANT_SYNCAPI "Enables Sync API support" ON)
+if(WANT_SYNCAPI)
+  add_definitions(-DTHREADED)
+  if(WIN32)
+    # Note that the generator expression ensures that `/MTd` is used when Debug
+    # configurations are built.
+    add_compile_options(/MT$<$<CONFIG:Debug>:d>)
+  endif()
+endif()
+
+# CppUnit option
+if(WIN32 OR APPLE)
+  # The tests do not yet compile on Windows or macOS,
+  # so we set this to off by default.
+  #
+  # Note that CMake does not have expressions except in conditionals,
+  # so we're left with this if/else/endif pattern.
+  set(DEFAULT_WANT_CPPUNIT OFF)
+else()
+  set(DEFAULT_WANT_CPPUNIT ON)
+endif()
+option(WANT_CPPUNIT "Enables CppUnit and tests" ${DEFAULT_WANT_CPPUNIT})
+
+# The function `to_have(in out)` converts a header name like `arpa/inet.h`
+# into an Autotools style preprocessor definition `HAVE_ARPA_INET_H`.
+# This is then set or unset in `configure_file()` step.
+#
+# Note that CMake functions do not have return values; instead an "out"
+# variable must be passed, and explicitly set with parent scope.
+function(to_have in out)
+  string(TOUPPER ${in} str)
+  string(REGEX REPLACE "/|\\." "_" str ${str})
+  set(${out} "HAVE_${str}" PARENT_SCOPE)
+endfunction()
+
+# include file checks
+foreach(f generated/zookeeper.jute.h generated/zookeeper.jute.c)
+  if(EXISTS "${LIBRARY_DIR}/${f}")
+    to_have(${f} name)
+    set(${name} 1)
+  else()
+    message(FATAL_ERROR
+      "jute files are missing!\n"
+      "Please run 'ant compile_jute' while in the ZooKeeper top level directory.")
+  endif()
+endforeach()
+
+# header checks
+include(CheckIncludeFile)
+set(check_headers
+  arpa/inet.h
+  dlfcn.h
+  fcntl.h
+  inttypes.h
+  memory.h
+  netdb.h
+  netinet/in.h
+  stdint.h
+  stdlib.h
+  string.h
+  strings.h
+  sys/socket.h
+  sys/stat.h
+  sys/time.h
+  sys/types.h
+  unistd.h
+  sys/utsname.h)
+
+foreach(f ${check_headers})
+  to_have(${f} name)
+  check_include_file(${f} ${name})
+endforeach()
+
+# function checks
+include(CheckFunctionExists)
+set(check_functions
+  getcwd
+  gethostbyname
+  gethostname
+  getlogin
+  getpwuid_r
+  gettimeofday
+  getuid
+  memmove
+  memset
+  poll
+  socket
+  strchr
+  strdup
+  strerror
+  strtol)
+
+foreach(fn ${check_functions})
+  to_have(${fn} name)
+  check_function_exists(${fn} ${name})
+endforeach()
+
+# library checks
+set(check_libraries rt m pthread)
+foreach(lib ${check_libraries})
+  to_have("lib${lib}" name)
+  find_library(${name} ${lib})
+endforeach()
+
+# IPv6 check
+include(CheckStructHasMember)
+check_struct_has_member("struct sockaddr_in6" sin6_addr "netinet/in.h" ZOO_IPV6_ENABLED)
+
+# configure
+configure_file(${LIBRARY_DIR}/cmake_config.h.in ${CMAKE_CURRENT_BINARY_DIR}/include/config.h)
+
+# hashtable library
+set(hashtable_sources ${LIBRARY_DIR}/src/hashtable/hashtable_itr.c ${LIBRARY_DIR}/src/hashtable/hashtable.c)
+add_library(hashtable STATIC ${hashtable_sources})
+
+# zookeeper library
+set(zookeeper_sources
+  ${LIBRARY_DIR}/src/zookeeper.c
+  ${LIBRARY_DIR}/src/recordio.c
+  ${LIBRARY_DIR}/generated/zookeeper.jute.c
+  ${LIBRARY_DIR}/src/zk_log.c
+  ${LIBRARY_DIR}/src/zk_hashtable.c
+)
+#  src/addrvec.c
+
+if(WANT_SYNCAPI)
+  list(APPEND zookeeper_sources ${LIBRARY_DIR}/src/mt_adaptor.c)
+else()
+  list(APPEND zookeeper_sources ${LIBRARY_DIR}/src/st_adaptor.c)
+endif()
+
+if(WIN32)
+  list(APPEND zookeeper_sources ${LIBRARY_DIR}/src/winport.c)
+endif()
+
+add_library(zookeeper STATIC ${zookeeper_sources})
+target_include_directories(zookeeper BEFORE PUBLIC ${LIBRARY_DIR}/include ${CMAKE_CURRENT_BINARY_DIR}/include ${LIBRARY_DIR}/generated)
+target_link_libraries(zookeeper PUBLIC
+  hashtable
+  $<$<PLATFORM_ID:Linux>:rt> # clock_gettime
+  $<$<PLATFORM_ID:Windows>:ws2_32>) # Winsock 2.0
+
+if(WANT_SYNCAPI AND NOT WIN32)
+  find_package(Threads REQUIRED)
+  target_link_libraries(zookeeper PUBLIC Threads::Threads)
+endif()
+
+# cli executable
+add_executable(cli ${LIBRARY_DIR}/src/cli.c)
+target_link_libraries(cli zookeeper)
+
+# load_gen executable
+if(WANT_SYNCAPI AND NOT WIN32)
+  add_executable(load_gen ${LIBRARY_DIR}/src/load_gen.c)
+  target_link_libraries(load_gen zookeeper)
+endif()
--- a/dbms/CMakeLists.txt
+++ b/dbms/CMakeLists.txt
@ -131,7 +131,6 @@ target_link_libraries (clickhouse_common_io
    ${LINK_LIBRARIES_ONLY_ON_X86_64}
    ${LZ4_LIBRARY}
    ${ZSTD_LIBRARY}
-    ${ZOOKEEPER_LIBRARY}
    ${DOUBLE_CONVERSION_LIBRARIES}
    ${Poco_Net_LIBRARY}
    ${Poco_Data_LIBRARY}
@ -158,10 +157,6 @@ if (NOT USE_INTERNAL_RE2_LIBRARY)
    target_include_directories (dbms BEFORE PRIVATE ${RE2_INCLUDE_DIR})
 endif ()

-if (NOT USE_INTERNAL_ZOOKEEPER_LIBRARY)
-    target_include_directories (clickhouse_common_io BEFORE PUBLIC ${ZOOKEEPER_INCLUDE_DIR})
-endif ()
-
 if (NOT USE_INTERNAL_BOOST_LIBRARY)
    target_include_directories (clickhouse_common_io BEFORE PUBLIC ${Boost_INCLUDE_DIRS})
 endif ()
--- a/dbms/cmake/version.cmake
+++ b/dbms/cmake/version.cmake
@ -1,6 +1,6 @@
 # This strings autochanged from release_lib.sh:
-set(VERSION_DESCRIBE v1.1.54363-testing)
-set(VERSION_REVISION 54363)
+set(VERSION_DESCRIBE v1.1.54371-testing)
+set(VERSION_REVISION 54371)
 # end of autochange

 set (VERSION_MAJOR 1)
--- a/dbms/src/AggregateFunctions/AggregateFunctionFactory.cpp
+++ b/dbms/src/AggregateFunctions/AggregateFunctionFactory.cpp
@ -70,7 +70,10 @@ AggregateFunctionPtr AggregateFunctionFactory::get(
        return combinator->transformAggregateFunction(nested_function, argument_types, parameters);
    }

-    return getImpl(name, argument_types, parameters, recursion_level);
+    auto res = getImpl(name, argument_types, parameters, recursion_level);
+    if (!res)
+        throw Exception("Logical error: AggregateFunctionFactory returned nullptr", ErrorCodes::LOGICAL_ERROR);
+    return res;
 }


--- a/dbms/src/AggregateFunctions/AggregateFunctionMaxIntersections.cpp
+++ b/dbms/src/AggregateFunctions/AggregateFunctionMaxIntersections.cpp
@ -0,0 +1,37 @@
+#include <AggregateFunctions/AggregateFunctionFactory.h>
+#include <AggregateFunctions/AggregateFunctionMaxIntersections.h>
+#include <AggregateFunctions/FactoryHelpers.h>
+#include <AggregateFunctions/Helpers.h>
+
+
+namespace DB
+{
+
+namespace
+{
+    AggregateFunctionPtr createAggregateFunctionMaxIntersections(
+        AggregateFunctionIntersectionsKind kind,
+        const std::string & name, const DataTypes & argument_types, const Array & parameters)
+    {
+        assertBinary(name, argument_types);
+        assertNoParameters(name, parameters);
+
+        AggregateFunctionPtr res(createWithNumericType<AggregateFunctionIntersectionsMax>(*argument_types[0], kind, argument_types));
+        if (!res)
+            throw Exception("Illegal types " + argument_types[0]->getName() + " and " + argument_types[1]->getName()
+                + " of argument for aggregate function " + name, ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
+
+        return res;
+    }
+}
+
+void registerAggregateFunctionsMaxIntersections(AggregateFunctionFactory & factory)
+{
+    factory.registerFunction("maxIntersections", [](const std::string & name, const DataTypes & argument_types, const Array & parameters)
+        { return createAggregateFunctionMaxIntersections(AggregateFunctionIntersectionsKind::Count, name, argument_types, parameters); });
+
+    factory.registerFunction("maxIntersectionsPosition", [](const std::string & name, const DataTypes & argument_types, const Array & parameters)
+        { return createAggregateFunctionMaxIntersections(AggregateFunctionIntersectionsKind::Position, name, argument_types, parameters); });
+}
+
+}
--- a/dbms/src/AggregateFunctions/AggregateFunctionMaxIntersections.h
+++ b/dbms/src/AggregateFunctions/AggregateFunctionMaxIntersections.h
@ -0,0 +1,170 @@
+#pragma once
+
+#include <common/logger_useful.h>
+
+#include <DataTypes/DataTypesNumber.h>
+#include <Columns/ColumnsNumber.h>
+
+#include <IO/ReadHelpers.h>
+#include <IO/WriteHelpers.h>
+
+#include <Common/ArenaAllocator.h>
+#include <Common/NaNUtils.h>
+
+#include <AggregateFunctions/IAggregateFunction.h>
+
+#define AGGREGATE_FUNCTION_MAX_INTERSECTIONS_MAX_ARRAY_SIZE 0xFFFFFF
+
+
+namespace DB
+{
+
+namespace ErrorCodes
+{
+    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
+    extern const int TOO_LARGE_ARRAY_SIZE;
+}
+
+
+/** maxIntersections: returns maximum count of the intersected intervals defined by start_column and end_column values,
+  * maxIntersectionsPosition: returns leftmost position of maximum intersection of intervals.
+  */
+
+/// Similar to GroupArrayNumericData.
+template <typename T>
+struct MaxIntersectionsData
+{
+    /// Left or right end of the interval and signed weight; with positive sign for begin of interval and negative sign for end of interval.
+    using Value = std::pair<T, Int64>;
+
+    // Switch to ordinary Allocator after 4096 bytes to avoid fragmentation and trash in Arena
+    using Allocator = MixedArenaAllocator<4096>;
+    using Array = PODArray<Value, 32, Allocator>;
+
+    Array value;
+};
+
+enum class AggregateFunctionIntersectionsKind
+{
+    Count,
+    Position
+};
+
+template <typename PointType>
+class AggregateFunctionIntersectionsMax final
+    : public IAggregateFunctionDataHelper<MaxIntersectionsData<PointType>, AggregateFunctionIntersectionsMax<PointType>>
+{
+private:
+    AggregateFunctionIntersectionsKind kind;
+
+public:
+    AggregateFunctionIntersectionsMax(AggregateFunctionIntersectionsKind kind_, const DataTypes & arguments)
+        : kind(kind_)
+    {
+        if (!arguments[0]->isNumber())
+            throw Exception{getName() + ": first argument must be represented by integer", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT};
+
+        if (!arguments[1]->isNumber())
+            throw Exception{getName() + ": second argument must be represented by integer", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT};
+
+        if (!arguments[0]->equals(*arguments[1]))
+            throw Exception{getName() + ": arguments must have the same type", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT};
+    }
+
+    String getName() const override
+    {
+        return kind == AggregateFunctionIntersectionsKind::Count
+            ? "maxIntersections"
+            : "maxIntersectionsPosition";
+    }
+
+    DataTypePtr getReturnType() const override
+    {
+        if (kind == AggregateFunctionIntersectionsKind::Count)
+            return std::make_shared<DataTypeUInt64>();
+        else
+            return std::make_shared<DataTypeNumber<PointType>>();
+    }
+
+    void add(AggregateDataPtr place, const IColumn ** columns, size_t row_num, Arena * arena) const override
+    {
+        PointType left = static_cast<const ColumnVector<PointType> &>(*columns[0]).getData()[row_num];
+        PointType right = static_cast<const ColumnVector<PointType> &>(*columns[1]).getData()[row_num];
+
+        if (!isNaN(left))
+            this->data(place).value.push_back(std::make_pair(left, Int64(1)), arena);
+
+        if (!isNaN(right))
+            this->data(place).value.push_back(std::make_pair(right, Int64(-1)), arena);
+    }
+
+    void merge(AggregateDataPtr place, ConstAggregateDataPtr rhs, Arena * arena) const override
+    {
+        auto & cur_elems = this->data(place);
+        auto & rhs_elems = this->data(rhs);
+
+        cur_elems.value.insert(rhs_elems.value.begin(), rhs_elems.value.end(), arena);
+    }
+
+    void serialize(ConstAggregateDataPtr place, WriteBuffer & buf) const override
+    {
+        const auto & value = this->data(place).value;
+        size_t size = value.size();
+        writeVarUInt(size, buf);
+        buf.write(reinterpret_cast<const char *>(&value[0]), size * sizeof(value[0]));
+    }
+
+    void deserialize(AggregateDataPtr place, ReadBuffer & buf, Arena * arena) const override
+    {
+        size_t size = 0;
+        readVarUInt(size, buf);
+
+        if (unlikely(size > AGGREGATE_FUNCTION_MAX_INTERSECTIONS_MAX_ARRAY_SIZE))
+            throw Exception("Too large array size", ErrorCodes::TOO_LARGE_ARRAY_SIZE);
+
+        auto & value = this->data(place).value;
+
+        value.resize(size, arena);
+        buf.read(reinterpret_cast<char *>(&value[0]), size * sizeof(value[0]));
+    }
+
+    void insertResultInto(ConstAggregateDataPtr place, IColumn & to) const override
+    {
+        Int64 current_intersections = 0;
+        Int64 max_intersections = 0;
+        PointType position_of_max_intersections = 0;
+
+        /// const_cast because we will sort the array
+        auto & array = const_cast<typename MaxIntersectionsData<PointType>::Array &>(this->data(place).value);
+
+        std::sort(array.begin(), array.end(), [](const auto & a, const auto & b) { return a.first < b.first; });
+
+        for (const auto & point_weight : array)
+        {
+            current_intersections += point_weight.second;
+            if (current_intersections > max_intersections)
+            {
+                max_intersections = current_intersections;
+                position_of_max_intersections = point_weight.first;
+            }
+        }
+
+        if (kind == AggregateFunctionIntersectionsKind::Count)
+        {
+            auto & result_column = static_cast<ColumnUInt64 &>(to).getData();
+            result_column.push_back(max_intersections);
+        }
+        else
+        {
+            auto & result_column = static_cast<ColumnVector<PointType> &>(to).getData();
+            result_column.push_back(position_of_max_intersections);
+        }
+    }
+
+    const char * getHeaderFilePath() const override
+    {
+        return __FILE__;
+    }
+};
+
+}
--- a/dbms/src/AggregateFunctions/AggregateFunctionSumMap.cpp
+++ b/dbms/src/AggregateFunctions/AggregateFunctionSumMap.cpp
@ -37,7 +37,11 @@ AggregateFunctionPtr createAggregateFunctionSumMap(const std::string & name, con
        values_types.push_back(array_type->getNestedType());
    }

-    return AggregateFunctionPtr(createWithNumericType<AggregateFunctionSumMap>(*keys_type, keys_type, std::move(values_types)));
+    AggregateFunctionPtr res(createWithNumericType<AggregateFunctionSumMap>(*keys_type, keys_type, std::move(values_types)));
+    if (!res)
+        throw Exception("Illegal type of argument for aggregate function " + name, ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
+
+    return res;
 }

 }
--- a/dbms/src/AggregateFunctions/AggregateFunctionUniq.cpp
+++ b/dbms/src/AggregateFunctions/AggregateFunctionUniq.cpp
@ -33,6 +33,10 @@ AggregateFunctionPtr createAggregateFunctionUniq(const std::string & name, const
 {
    assertNoParameters(name, params);

+    if (argument_types.empty())
+        throw Exception("Incorrect number of arguments for aggregate function " + name,
+            ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+
    if (argument_types.size() == 1)
    {
        const IDataType & argument_type = *argument_types[0];
@ -51,23 +55,18 @@ AggregateFunctionPtr createAggregateFunctionUniq(const std::string & name, const
            return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic, true>>(argument_types);
        else if (typeid_cast<const DataTypeUUID *>(&argument_type))
            return std::make_shared<AggregateFunctionUniq<DataTypeUUID::FieldType, Data>>();
-        else
-            throw Exception("Illegal type " + argument_types[0]->getName() + " of argument for aggregate function " + name,
-                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }
-    else if (argument_types.size() > 1)
+    else
    {
        /// If there are several arguments, then no tuples allowed among them.
        for (const auto & type : argument_types)
            if (typeid_cast<const DataTypeTuple *>(type.get()))
                throw Exception("Tuple argument of function " + name + " must be the only argument",
                    ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
-
-        return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic, false>>(argument_types);
    }
-    else
-        throw Exception("Incorrect number of arguments for aggregate function " + name,
-            ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+
+    /// "Variadic" method also works as a fallback generic case for single argument.
+    return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic, false>>(argument_types);
 }

 template <template <typename> class Data, typename DataForVariadic>
@ -75,6 +74,10 @@ AggregateFunctionPtr createAggregateFunctionUniq(const std::string & name, const
 {
    assertNoParameters(name, params);

+    if (argument_types.empty())
+        throw Exception("Incorrect number of arguments for aggregate function " + name,
+            ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+
    if (argument_types.size() == 1)
    {
        const IDataType & argument_type = *argument_types[0];
@ -93,23 +96,18 @@ AggregateFunctionPtr createAggregateFunctionUniq(const std::string & name, const
            return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic, true>>(argument_types);
        else if (typeid_cast<const DataTypeUUID *>(&argument_type))
            return std::make_shared<AggregateFunctionUniq<DataTypeUUID::FieldType, Data<DataTypeUUID::FieldType>>>();
-        else
-            throw Exception("Illegal type " + argument_types[0]->getName() + " of argument for aggregate function " + name,
-                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }
-    else if (argument_types.size() > 1)
+    else
    {
        /// If there are several arguments, then no tuples allowed among them.
        for (const auto & type : argument_types)
            if (typeid_cast<const DataTypeTuple *>(type.get()))
                throw Exception("Tuple argument of function " + name + " must be the only argument",
                    ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
-
-        return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic, false>>(argument_types);
    }
-    else
-        throw Exception("Incorrect number of arguments for aggregate function " + name,
-            ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+
+    /// "Variadic" method also works as a fallback generic case for single argument.
+    return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic, false>>(argument_types);
 }

 }
--- a/dbms/src/AggregateFunctions/AggregateFunctionUniq.h
+++ b/dbms/src/AggregateFunctions/AggregateFunctionUniq.h
@ -122,8 +122,8 @@ struct AggregateFunctionUniqExactData<String>
    static String getName() { return "uniqExact"; }
 };

-template <typename T, HyperLogLogMode mode>
-struct BaseUniqCombinedData
+template <typename T>
+struct AggregateFunctionUniqCombinedData
 {
    using Key = UInt32;
    using Set = CombinedCardinalityEstimator<
@ -135,14 +135,15 @@ struct BaseUniqCombinedData
        TrivialHash,
        UInt32,
        HyperLogLogBiasEstimator<UniqCombinedBiasData>,
-        mode
-    >;
+        HyperLogLogMode::FullFeatured>;

    Set set;
+
+    static String getName() { return "uniqCombined"; }
 };

-template <HyperLogLogMode mode>
-struct BaseUniqCombinedData<String, mode>
+template <>
+struct AggregateFunctionUniqCombinedData<String>
 {
    using Key = UInt64;
    using Set = CombinedCardinalityEstimator<
@ -154,44 +155,14 @@ struct BaseUniqCombinedData<String, mode>
        TrivialHash,
        UInt64,
        HyperLogLogBiasEstimator<UniqCombinedBiasData>,
-        mode
-    >;
+        HyperLogLogMode::FullFeatured>;

    Set set;
-};

-/// Aggregate functions uniqCombinedRaw, uniqCombinedLinearCounting, and uniqCombinedBiasCorrected
-///  are intended for development of new versions of the uniqCombined function.
-/// Users should only use uniqCombined.
-
-template <typename T>
-struct AggregateFunctionUniqCombinedRawData
-    : public BaseUniqCombinedData<T, HyperLogLogMode::Raw>
-{
-    static String getName() { return "uniqCombinedRaw"; }
-};
-
-template <typename T>
-struct AggregateFunctionUniqCombinedLinearCountingData
-    : public BaseUniqCombinedData<T, HyperLogLogMode::LinearCounting>
-{
-    static String getName() { return "uniqCombinedLinearCounting"; }
-};
-
-template <typename T>
-struct AggregateFunctionUniqCombinedBiasCorrectedData
-    : public BaseUniqCombinedData<T, HyperLogLogMode::BiasCorrected>
-{
-    static String getName() { return "uniqCombinedBiasCorrected"; }
-};
-
-template <typename T>
-struct AggregateFunctionUniqCombinedData
-    : public BaseUniqCombinedData<T, HyperLogLogMode::FullFeatured>
-{
    static String getName() { return "uniqCombined"; }
 };

+
 namespace detail
 {

@ -288,10 +259,7 @@ struct OneAdder
                data.set.insert(CityHash_v1_0_2::CityHash64(value.data, value.size));
            }
        }
-        else if constexpr (std::is_same_v<Data, AggregateFunctionUniqCombinedRawData<T>>
-            || std::is_same_v<Data, AggregateFunctionUniqCombinedLinearCountingData<T>>
-            || std::is_same_v<Data, AggregateFunctionUniqCombinedBiasCorrectedData<T>>
-            || std::is_same_v<Data, AggregateFunctionUniqCombinedData<T>>)
+        else if constexpr (std::is_same_v<Data, AggregateFunctionUniqCombinedData<T>>)
        {
            if constexpr (!std::is_same_v<T, String>)
            {
@ -371,7 +339,7 @@ public:

 /** For multiple arguments. To compute, hashes them.
  * You can pass multiple arguments as is; You can also pass one argument - a tuple.
-  * But (for the possibility of effective implementation), you can not pass several arguments, among which there are tuples.
+  * But (for the possibility of efficient implementation), you can not pass several arguments, among which there are tuples.
  */
 template <typename Data, bool argument_is_tuple>
 class AggregateFunctionUniqVariadic final : public IAggregateFunctionDataHelper<Data, AggregateFunctionUniqVariadic<Data, argument_is_tuple>>
--- a/dbms/src/AggregateFunctions/AggregateFunctionUniqUpTo.cpp
+++ b/dbms/src/AggregateFunctions/AggregateFunctionUniqUpTo.cpp
@ -42,6 +42,10 @@ AggregateFunctionPtr createAggregateFunctionUniqUpTo(const std::string & name, c
        threshold = threshold_param;
    }

+    if (argument_types.empty())
+        throw Exception("Incorrect number of arguments for aggregate function " + name,
+            ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+
    if (argument_types.size() == 1)
    {
        const IDataType & argument_type = *argument_types[0];
@ -60,22 +64,18 @@ AggregateFunctionPtr createAggregateFunctionUniqUpTo(const std::string & name, c
            return std::make_shared<AggregateFunctionUniqUpToVariadic<true>>(argument_types, threshold);
        else if (typeid_cast<const DataTypeUUID *>(&argument_type))
            return std::make_shared<AggregateFunctionUniqUpTo<DataTypeUUID::FieldType>>(threshold);
-        else
-            throw Exception("Illegal type " + argument_types[0]->getName() + " of argument for aggregate function " + name, ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
    }
-    else if (argument_types.size() > 1)
+    else
    {
        /// If there are several arguments, then no tuples allowed among them.
        for (const auto & type : argument_types)
            if (typeid_cast<const DataTypeTuple *>(type.get()))
                throw Exception("Tuple argument of function " + name + " must be the only argument",
                    ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);
-
-        return std::make_shared<AggregateFunctionUniqUpToVariadic<false>>(argument_types, threshold);
    }
-    else
-        throw Exception("Incorrect number of arguments for aggregate function " + name,
-            ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH);
+
+    /// "Variadic" method also works as a fallback generic case for single argument.
+    return std::make_shared<AggregateFunctionUniqUpToVariadic<false>>(argument_types, threshold);
 }

 }
--- a/dbms/src/AggregateFunctions/QuantileExact.h
+++ b/dbms/src/AggregateFunctions/QuantileExact.h
@ -1,6 +1,7 @@
 #pragma once

 #include <Common/PODArray.h>
+#include <Common/NaNUtils.h>
 #include <IO/WriteBuffer.h>
 #include <IO/ReadBuffer.h>
 #include <Core/Types.h>
@ -32,7 +33,9 @@ struct QuantileExact

    void add(const Value & x)
    {
-        array.push_back(x);
+        /// We must skip NaNs as they are not compatible with comparison sorting.
+        if (!isNaN(x))
+            array.push_back(x);
    }

    template <typename Weight>
--- a/dbms/src/AggregateFunctions/QuantileExactWeighted.h
+++ b/dbms/src/AggregateFunctions/QuantileExactWeighted.h
@ -1,6 +1,7 @@
 #pragma once

 #include <Common/HashTable/HashMap.h>
+#include <Common/NaNUtils.h>


 namespace DB
@ -33,12 +34,15 @@ struct QuantileExactWeighted

    void add(const Value & x)
    {
-        ++map[x];
+        /// We must skip NaNs as they are not compatible with comparison sorting.
+        if (!isNaN(x))
+            ++map[x];
    }

    void add(const Value & x, const Weight & weight)
    {
-        map[x] += weight;
+        if (!isNaN(x))
+            map[x] += weight;
    }

    void merge(const QuantileExactWeighted & rhs)
--- a/dbms/src/AggregateFunctions/QuantilesCommon.h
+++ b/dbms/src/AggregateFunctions/QuantilesCommon.h
@ -4,6 +4,7 @@

 #include <Core/Field.h>
 #include <Common/FieldVisitors.h>
+#include <Common/NaNUtils.h>


 namespace DB
@ -12,6 +13,7 @@ namespace DB
 namespace ErrorCodes
 {
    extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
+    extern const int PARAMETER_OUT_OF_BOUND;
 }


@ -55,6 +57,10 @@ struct QuantileLevels
        for (size_t i = 0; i < size; ++i)
        {
            levels[i] = applyVisitor(FieldVisitorConvertToNumber<Float64>(), params[i]);
+
+            if (isNaN(levels[i]) || levels[i] < 0 || levels[i] > 1)
+                throw Exception("Quantile level is out of range [0..1]", ErrorCodes::PARAMETER_OUT_OF_BOUND);
+
            permutation[i] = i;
        }

--- a/dbms/src/AggregateFunctions/ReservoirSampler.h
+++ b/dbms/src/AggregateFunctions/ReservoirSampler.h
@ -9,6 +9,7 @@
 #include <IO/ReadHelpers.h>
 #include <IO/WriteHelpers.h>
 #include <Common/PODArray.h>
+#include <Common/NaNUtils.h>
 #include <Poco/Exception.h>
 #include <pcg_random.hpp>

@ -67,6 +68,9 @@ public:

    void insert(const T & v)
    {
+        if (isNaN(v))
+            return;
+
        sorted = false;
        ++total_values;
        if (samples.size() < sample_count)
--- a/dbms/src/AggregateFunctions/ReservoirSamplerDeterministic.h
+++ b/dbms/src/AggregateFunctions/ReservoirSamplerDeterministic.h
@ -11,6 +11,7 @@
 #include <IO/ReadHelpers.h>
 #include <IO/WriteHelpers.h>
 #include <Common/PODArray.h>
+#include <Common/NaNUtils.h>
 #include <Poco/Exception.h>


@ -66,6 +67,9 @@ public:

    void insert(const T & v, const UInt64 determinator)
    {
+        if (isNaN(v))
+            return;
+
        const UInt32 hash = intHash64(determinator);
        if (!good(hash))
            return;
--- a/dbms/src/AggregateFunctions/registerAggregateFunctions.cpp
+++ b/dbms/src/AggregateFunctions/registerAggregateFunctions.cpp
@ -23,6 +23,7 @@ void registerAggregateFunctionsUniq(AggregateFunctionFactory &);
 void registerAggregateFunctionUniqUpTo(AggregateFunctionFactory &);
 void registerAggregateFunctionTopK(AggregateFunctionFactory &);
 void registerAggregateFunctionsBitwise(AggregateFunctionFactory &);
+void registerAggregateFunctionsMaxIntersections(AggregateFunctionFactory &);

 void registerAggregateFunctionCombinatorIf(AggregateFunctionCombinatorFactory &);
 void registerAggregateFunctionCombinatorArray(AggregateFunctionCombinatorFactory &);
@ -53,6 +54,7 @@ void registerAggregateFunctions()
        registerAggregateFunctionUniqUpTo(factory);
        registerAggregateFunctionTopK(factory);
        registerAggregateFunctionsBitwise(factory);
+        registerAggregateFunctionsMaxIntersections(factory);
    }

    {
--- a/dbms/src/Analyzers/AnalyzeColumns.cpp
+++ b/dbms/src/Analyzers/AnalyzeColumns.cpp
@ -173,7 +173,7 @@ ASTPtr createASTIdentifierForColumnInTable(const String & column, const CollectT
 void createASTsForAllColumnsInTable(const CollectTables::TableInfo & table, ASTs & res)
 {
    if (table.storage)
-        for (const auto & name : table.storage->getColumnNamesList())
+        for (const auto & name : table.storage->getColumns().getNamesOfPhysical())
            res.emplace_back(createASTIdentifierForColumnInTable(name, table));
    else
        for (size_t i = 0, size = table.structure_of_subquery.columns(); i < size; ++i)
@ -315,7 +315,7 @@ void processIdentifier(
    }
    else if (table->storage)
    {
-        info.data_type = table->storage->getDataTypeByName(column_name);
+        info.data_type = table->storage->getColumn(column_name).type;
    }
    else
        throw Exception("Logical error: no storage and no structure of subquery is specified for table", ErrorCodes::LOGICAL_ERROR);
--- a/dbms/src/Analyzers/ExecuteTableFunctions.cpp
+++ b/dbms/src/Analyzers/ExecuteTableFunctions.cpp
@ -72,7 +72,7 @@ void ExecuteTableFunctions::dump(WriteBuffer & out) const
    {
        writeString(table.second->getName(), out);
        writeCString("\n\n", out);
-        writeString(table.second->getColumnsList().toString(), out);
+        writeString(table.second->getColumns().getAllPhysical().toString(), out);
        writeCString("\n", out);
    }
 }
--- a/dbms/src/Client/Connection.cpp
+++ b/dbms/src/Client/Connection.cpp
@ -12,6 +12,7 @@
 #include <DataStreams/NativeBlockInputStream.h>
 #include <DataStreams/NativeBlockOutputStream.h>
 #include <Client/Connection.h>
+#include <Client/TimeoutSetter.h>
 #include <Common/ClickHouseRevision.h>
 #include <Common/Exception.h>
 #include <Common/NetException.h>
@ -50,14 +51,15 @@ void Connection::connect()
        if (connected)
            disconnect();

-        LOG_TRACE(log_wrapper.get(), "Connecting. Database: " << (default_database.empty() ? "(not specified)" : default_database) << ". User: " << user);
+        LOG_TRACE(log_wrapper.get(), "Connecting. Database: " << (default_database.empty() ? "(not specified)" : default_database) << ". User: " << user
+        << (static_cast<bool>(secure) ? ". Secure" : "") << (static_cast<bool>(compression) ? "" : ". Uncompressed") );

-        if (static_cast<bool>(encryption))
+        if (static_cast<bool>(secure))
        {
 #if Poco_NetSSL_FOUND
            socket = std::make_unique<Poco::Net::SecureStreamSocket>();
 #else
-            throw Exception{"tcp_ssl protocol is disabled because poco library was built without NetSSL support.", ErrorCodes::SUPPORT_IS_DISABLED};
+            throw Exception{"tcp_secure protocol is disabled because poco library was built without NetSSL support.", ErrorCodes::SUPPORT_IS_DISABLED};
 #endif
        }
        else
@ -148,6 +150,10 @@ void Connection::receiveHello()
        {
            readStringBinary(server_timezone, *in);
        }
+        if (server_revision >= DBMS_MIN_REVISION_WITH_SERVER_DISPLAY_NAME)
+        {
+            readStringBinary(server_display_name, *in);
+        }
    }
    else if (packet_type == Protocol::Server::Exception)
        receiveException()->rethrow();
@ -203,6 +209,14 @@ const String & Connection::getServerTimezone()
    return server_timezone;
 }

+const String & Connection::getServerDisplayName()
+{
+    if (!connected)
+        connect();
+
+    return server_display_name;
+}
+
 void Connection::forceConnected()
 {
    if (!connected)
@ -216,32 +230,6 @@ void Connection::forceConnected()
    }
 }

-struct TimeoutSetter
-{
-    TimeoutSetter(Poco::Net::StreamSocket & socket_, const Poco::Timespan & timeout_)
-        : socket(socket_), timeout(timeout_)
-    {
-        old_send_timeout = socket.getSendTimeout();
-        old_receive_timeout = socket.getReceiveTimeout();
-
-        if (old_send_timeout > timeout)
-            socket.setSendTimeout(timeout);
-        if (old_receive_timeout > timeout)
-            socket.setReceiveTimeout(timeout);
-    }
-
-    ~TimeoutSetter()
-    {
-        socket.setSendTimeout(old_send_timeout);
-        socket.setReceiveTimeout(old_receive_timeout);
-    }
-
-    Poco::Net::StreamSocket & socket;
-    Poco::Timespan timeout;
-    Poco::Timespan old_send_timeout;
-    Poco::Timespan old_receive_timeout;
-};
-
 bool Connection::ping()
 {
    // LOG_TRACE(log_wrapper.get(), "Ping");
--- a/dbms/src/Client/Connection.h
+++ b/dbms/src/Client/Connection.h
@ -58,14 +58,14 @@ public:
        const ConnectionTimeouts & timeouts_,
        const String & client_name_ = "client",
        Protocol::Compression compression_ = Protocol::Compression::Enable,
-        Protocol::Encryption encryption_ = Protocol::Encryption::Disable,
+        Protocol::Secure secure_ = Protocol::Secure::Disable,
        Poco::Timespan sync_request_timeout_ = Poco::Timespan(DBMS_DEFAULT_SYNC_REQUEST_TIMEOUT_SEC, 0))
        :
        host(host_), port(port_), default_database(default_database_),
        user(user_), password(password_), resolved_address(host, port),
        client_name(client_name_),
        compression(compression_),
-        encryption(encryption_),
+        secure(secure_),
        timeouts(timeouts_),
        sync_request_timeout(sync_request_timeout_),
        log_wrapper(*this)
@ -84,7 +84,7 @@ public:
        const ConnectionTimeouts & timeouts_,
        const String & client_name_ = "client",
        Protocol::Compression compression_ = Protocol::Compression::Enable,
-        Protocol::Encryption encryption_ = Protocol::Encryption::Disable,
+        Protocol::Secure secure_ = Protocol::Secure::Disable,
        Poco::Timespan sync_request_timeout_ = Poco::Timespan(DBMS_DEFAULT_SYNC_REQUEST_TIMEOUT_SEC, 0))
        :
        host(host_), port(port_),
@ -93,7 +93,7 @@ public:
        resolved_address(resolved_address_),
        client_name(client_name_),
        compression(compression_),
-        encryption(encryption_),
+        secure(secure_),
        timeouts(timeouts_),
        sync_request_timeout(sync_request_timeout_),
        log_wrapper(*this)
@ -134,6 +134,7 @@ public:
    void getServerVersion(String & name, UInt64 & version_major, UInt64 & version_minor, UInt64 & revision);

    const String & getServerTimezone();
+    const String & getServerDisplayName();

    /// For log and exception messages.
    const String & getDescription() const;
@ -213,6 +214,7 @@ private:
    UInt64 server_version_minor = 0;
    UInt64 server_revision = 0;
    String server_timezone;
+    String server_display_name;

    std::unique_ptr<Poco::Net::StreamSocket> socket;
    std::shared_ptr<ReadBuffer> in;
@ -220,7 +222,7 @@ private:

    String query_id;
    Protocol::Compression compression;        /// Enable data compression for communication.
-    Protocol::Encryption encryption;             /// Enable data encryption for communication.
+    Protocol::Secure secure;             /// Enable data encryption for communication.

    /// What compression settings to use while sending data for INSERT queries and external tables.
    CompressionSettings compression_settings;
--- a/dbms/src/Client/ConnectionPool.h
+++ b/dbms/src/Client/ConnectionPool.h
@ -51,11 +51,12 @@ public:
            const ConnectionTimeouts & timeouts,
            const String & client_name_ = "client",
            Protocol::Compression compression_ = Protocol::Compression::Enable,
-            Protocol::Encryption encryption_ = Protocol::Encryption::Disable)
+            Protocol::Secure secure_ = Protocol::Secure::Disable)
       : Base(max_connections_, &Logger::get("ConnectionPool (" + host_ + ":" + toString(port_) + ")")),
        host(host_), port(port_), default_database(default_database_),
        user(user_), password(password_), resolved_address(host_, port_),
-        client_name(client_name_), compression(compression_), encryption(encryption_),
+        client_name(client_name_), compression(compression_),
+        secure{secure_},
        timeouts(timeouts)
    {
    }
@ -67,11 +68,12 @@ public:
            const ConnectionTimeouts & timeouts,
            const String & client_name_ = "client",
            Protocol::Compression compression_ = Protocol::Compression::Enable,
-            Protocol::Encryption encryption_ = Protocol::Encryption::Disable)
+            Protocol::Secure secure_ = Protocol::Secure::Disable)
        : Base(max_connections_, &Logger::get("ConnectionPool (" + host_ + ":" + toString(port_) + ")")),
        host(host_), port(port_), default_database(default_database_),
        user(user_), password(password_), resolved_address(resolved_address_),
-        client_name(client_name_), compression(compression_), encryption(encryption_),
+        client_name(client_name_), compression(compression_),
+        secure{secure_},
        timeouts(timeouts)
    {
    }
@ -102,7 +104,7 @@ protected:
        return std::make_shared<Connection>(
            host, port, resolved_address,
            default_database, user, password, timeouts,
-            client_name, compression, encryption);
+            client_name, compression, secure);
    }

 private:
@ -119,7 +121,7 @@ private:

    String client_name;
    Protocol::Compression compression;        /// Whether to compress data when interacting with the server.
-    Protocol::Encryption encryption;          /// Whether to encrypt data when interacting with the server.
+    Protocol::Secure secure;          /// Whether to encrypt data when interacting with the server.

    ConnectionTimeouts timeouts;
 };
--- a/dbms/src/Client/TimeoutSetter.h
+++ b/dbms/src/Client/TimeoutSetter.h
@ -0,0 +1,46 @@
+#pragma once
+
+#include <Poco/Timespan.h>
+#include <Poco/Net/StreamSocket.h>
+
+
+namespace DB
+{
+
+/// Temporarily overrides socket send/recieve timeouts and reset them back into destructor
+/// Timeouts could be only decreased
+struct TimeoutSetter
+{
+    TimeoutSetter(Poco::Net::StreamSocket & socket_, const Poco::Timespan & send_timeout_, const Poco::Timespan & recieve_timeout_)
+        : socket(socket_), send_timeout(send_timeout_), recieve_timeout(recieve_timeout_)
+    {
+        old_send_timeout = socket.getSendTimeout();
+        old_receive_timeout = socket.getReceiveTimeout();
+
+        if (old_send_timeout > send_timeout)
+            socket.setSendTimeout(send_timeout);
+
+        if (old_receive_timeout > recieve_timeout)
+            socket.setReceiveTimeout(recieve_timeout);
+    }
+
+    TimeoutSetter(Poco::Net::StreamSocket & socket_, const Poco::Timespan & timeout_)
+        : TimeoutSetter(socket_, timeout_, timeout_) {}
+
+    ~TimeoutSetter()
+    {
+        socket.setSendTimeout(old_send_timeout);
+        socket.setReceiveTimeout(old_receive_timeout);
+    }
+
+    Poco::Net::StreamSocket & socket;
+
+    Poco::Timespan send_timeout;
+    Poco::Timespan recieve_timeout;
+
+    Poco::Timespan old_send_timeout;
+    Poco::Timespan old_receive_timeout;
+};
+
+
+}
--- a/dbms/src/Columns/ColumnAggregateFunction.cpp
+++ b/dbms/src/Columns/ColumnAggregateFunction.cpp
@ -113,7 +113,7 @@ void ColumnAggregateFunction::insertRangeFrom(const IColumn & from, size_t start
 }


-MutableColumnPtr ColumnAggregateFunction::filter(const Filter & filter, ssize_t result_size_hint) const
+ColumnPtr ColumnAggregateFunction::filter(const Filter & filter, ssize_t result_size_hint) const
 {
    size_t size = getData().size();
    if (size != filter.size())
@ -140,7 +140,7 @@ MutableColumnPtr ColumnAggregateFunction::filter(const Filter & filter, ssize_t
 }


-MutableColumnPtr ColumnAggregateFunction::permute(const Permutation & perm, size_t limit) const
+ColumnPtr ColumnAggregateFunction::permute(const Permutation & perm, size_t limit) const
 {
    size_t size = getData().size();

@ -325,7 +325,7 @@ void ColumnAggregateFunction::popBack(size_t n)
    data.resize_assume_reserved(new_size);
 }

-MutableColumnPtr ColumnAggregateFunction::replicate(const IColumn::Offsets & offsets) const
+ColumnPtr ColumnAggregateFunction::replicate(const IColumn::Offsets & offsets) const
 {
    size_t size = data.size();
    if (size != offsets.size())
--- a/dbms/src/Columns/ColumnAggregateFunction.h
+++ b/dbms/src/Columns/ColumnAggregateFunction.h
@ -152,11 +152,11 @@ public:

    void popBack(size_t n) override;

-    MutableColumnPtr filter(const Filter & filter, ssize_t result_size_hint) const override;
+    ColumnPtr filter(const Filter & filter, ssize_t result_size_hint) const override;

-    MutableColumnPtr permute(const Permutation & perm, size_t limit) const override;
+    ColumnPtr permute(const Permutation & perm, size_t limit) const override;

-    MutableColumnPtr replicate(const Offsets & offsets) const override;
+    ColumnPtr replicate(const Offsets & offsets) const override;

    MutableColumns scatter(ColumnIndex num_columns, const Selector & selector) const override;

--- a/dbms/src/Columns/ColumnArray.cpp
+++ b/dbms/src/Columns/ColumnArray.cpp
@ -31,10 +31,10 @@ namespace ErrorCodes
 }


-ColumnArray::ColumnArray(const ColumnPtr & nested_column, const ColumnPtr & offsets_column)
-    : data(nested_column), offsets(offsets_column)
+ColumnArray::ColumnArray(MutableColumnPtr && nested_column, MutableColumnPtr && offsets_column)
+    : data(std::move(nested_column)), offsets(std::move(offsets_column))
 {
-    if (!typeid_cast<const ColumnOffsets *>(offsets_column.get()))
+    if (!typeid_cast<const ColumnOffsets *>(offsets.get()))
        throw Exception("offsets_column must be a ColumnUInt64", ErrorCodes::ILLEGAL_COLUMN);

    /** NOTE
@ -43,8 +43,8 @@ ColumnArray::ColumnArray(const ColumnPtr & nested_column, const ColumnPtr & offs
      */
 }

-ColumnArray::ColumnArray(const ColumnPtr & nested_column)
-    : data(nested_column)
+ColumnArray::ColumnArray(MutableColumnPtr && nested_column)
+    : data(std::move(nested_column))
 {
    if (!data->empty())
        throw Exception("Not empty data passed to ColumnArray, but no offsets passed", ErrorCodes::ILLEGAL_COLUMN);
@ -317,7 +317,7 @@ bool ColumnArray::hasEqualOffsets(const ColumnArray & other) const
 }


-MutableColumnPtr ColumnArray::convertToFullColumnIfConst() const
+ColumnPtr ColumnArray::convertToFullColumnIfConst() const
 {
    ColumnPtr new_data;

@ -391,7 +391,7 @@ void ColumnArray::insertRangeFrom(const IColumn & src, size_t start, size_t leng
 }


-MutableColumnPtr ColumnArray::filter(const Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnArray::filter(const Filter & filt, ssize_t result_size_hint) const
 {
    if (typeid_cast<const ColumnUInt8 *>(data.get()))      return filterNumber<UInt8>(filt, result_size_hint);
    if (typeid_cast<const ColumnUInt16 *>(data.get()))     return filterNumber<UInt16>(filt, result_size_hint);
@ -410,7 +410,7 @@ MutableColumnPtr ColumnArray::filter(const Filter & filt, ssize_t result_size_hi
 }

 template <typename T>
-MutableColumnPtr ColumnArray::filterNumber(const Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnArray::filterNumber(const Filter & filt, ssize_t result_size_hint) const
 {
    if (getOffsets().size() == 0)
        return ColumnArray::create(data);
@ -424,7 +424,7 @@ MutableColumnPtr ColumnArray::filterNumber(const Filter & filt, ssize_t result_s
    return std::move(res);
 }

-MutableColumnPtr ColumnArray::filterString(const Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnArray::filterString(const Filter & filt, ssize_t result_size_hint) const
 {
    size_t col_size = getOffsets().size();
    if (col_size != filt.size())
@ -492,7 +492,7 @@ MutableColumnPtr ColumnArray::filterString(const Filter & filt, ssize_t result_s
    return std::move(res);
 }

-MutableColumnPtr ColumnArray::filterGeneric(const Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnArray::filterGeneric(const Filter & filt, ssize_t result_size_hint) const
 {
    size_t size = getOffsets().size();
    if (size != filt.size())
@ -537,7 +537,7 @@ MutableColumnPtr ColumnArray::filterGeneric(const Filter & filt, ssize_t result_
    return std::move(res);
 }

-MutableColumnPtr ColumnArray::filterNullable(const Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnArray::filterNullable(const Filter & filt, ssize_t result_size_hint) const
 {
    if (getOffsets().size() == 0)
        return ColumnArray::create(data);
@ -560,7 +560,7 @@ MutableColumnPtr ColumnArray::filterNullable(const Filter & filt, ssize_t result
        filtered_offsets);
 }

-MutableColumnPtr ColumnArray::filterTuple(const Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnArray::filterTuple(const Filter & filt, ssize_t result_size_hint) const
 {
    if (getOffsets().size() == 0)
        return ColumnArray::create(data);
@ -576,7 +576,8 @@ MutableColumnPtr ColumnArray::filterTuple(const Filter & filt, ssize_t result_si

    Columns temporary_arrays(tuple_size);
    for (size_t i = 0; i < tuple_size; ++i)
-        temporary_arrays[i] = ColumnArray(tuple.getColumns()[i], getOffsetsPtr()).filter(filt, result_size_hint);
+        temporary_arrays[i] = ColumnArray(tuple.getColumns()[i]->assumeMutable(), getOffsetsPtr()->assumeMutable())
+                .filter(filt, result_size_hint);

    Columns tuple_columns(tuple_size);
    for (size_t i = 0; i < tuple_size; ++i)
@ -588,7 +589,7 @@ MutableColumnPtr ColumnArray::filterTuple(const Filter & filt, ssize_t result_si
 }


-MutableColumnPtr ColumnArray::permute(const Permutation & perm, size_t limit) const
+ColumnPtr ColumnArray::permute(const Permutation & perm, size_t limit) const
 {
    size_t size = getOffsets().size();

@ -652,7 +653,7 @@ void ColumnArray::getPermutation(bool reverse, size_t limit, int nan_direction_h
 }


-MutableColumnPtr ColumnArray::replicate(const Offsets & replicate_offsets) const
+ColumnPtr ColumnArray::replicate(const Offsets & replicate_offsets) const
 {
    if (typeid_cast<const ColumnUInt8 *>(data.get()))     return replicateNumber<UInt8>(replicate_offsets);
    if (typeid_cast<const ColumnUInt16 *>(data.get()))    return replicateNumber<UInt16>(replicate_offsets);
@ -673,7 +674,7 @@ MutableColumnPtr ColumnArray::replicate(const Offsets & replicate_offsets) const


 template <typename T>
-MutableColumnPtr ColumnArray::replicateNumber(const Offsets & replicate_offsets) const
+ColumnPtr ColumnArray::replicateNumber(const Offsets & replicate_offsets) const
 {
    size_t col_size = size();
    if (col_size != replicate_offsets.size())
@ -721,7 +722,7 @@ MutableColumnPtr ColumnArray::replicateNumber(const Offsets & replicate_offsets)
 }


-MutableColumnPtr ColumnArray::replicateString(const Offsets & replicate_offsets) const
+ColumnPtr ColumnArray::replicateString(const Offsets & replicate_offsets) const
 {
    size_t col_size = size();
    if (col_size != replicate_offsets.size())
@ -796,7 +797,7 @@ MutableColumnPtr ColumnArray::replicateString(const Offsets & replicate_offsets)
 }


-MutableColumnPtr ColumnArray::replicateConst(const Offsets & replicate_offsets) const
+ColumnPtr ColumnArray::replicateConst(const Offsets & replicate_offsets) const
 {
    size_t col_size = size();
    if (col_size != replicate_offsets.size())
@ -834,7 +835,7 @@ MutableColumnPtr ColumnArray::replicateConst(const Offsets & replicate_offsets)
 }


-MutableColumnPtr ColumnArray::replicateGeneric(const Offsets & replicate_offsets) const
+ColumnPtr ColumnArray::replicateGeneric(const Offsets & replicate_offsets) const
 {
    size_t col_size = size();
    if (col_size != replicate_offsets.size())
@ -860,25 +861,27 @@ MutableColumnPtr ColumnArray::replicateGeneric(const Offsets & replicate_offsets
 }


-MutableColumnPtr ColumnArray::replicateNullable(const Offsets & replicate_offsets) const
+ColumnPtr ColumnArray::replicateNullable(const Offsets & replicate_offsets) const
 {
    const ColumnNullable & nullable = static_cast<const ColumnNullable &>(*data);

    /// Make temporary arrays for each components of Nullable. Then replicate them independently and collect back to result.
    /// NOTE Offsets are calculated twice and it is redundant.

-    auto array_of_nested = ColumnArray(nullable.getNestedColumnPtr(), getOffsetsPtr()).replicate(replicate_offsets);
-    auto array_of_null_map = ColumnArray(nullable.getNullMapColumnPtr(), getOffsetsPtr()).replicate(replicate_offsets);
+    auto array_of_nested = ColumnArray(nullable.getNestedColumnPtr()->assumeMutable(), getOffsetsPtr()->assumeMutable())
+            .replicate(replicate_offsets);
+    auto array_of_null_map = ColumnArray(nullable.getNullMapColumnPtr()->assumeMutable(), getOffsetsPtr()->assumeMutable())
+            .replicate(replicate_offsets);

    return ColumnArray::create(
        ColumnNullable::create(
-            static_cast<ColumnArray &>(*array_of_nested).getDataPtr(),
-            static_cast<ColumnArray &>(*array_of_null_map).getDataPtr()),
-        static_cast<ColumnArray &>(*array_of_nested).getOffsetsPtr());
+            static_cast<const ColumnArray &>(*array_of_nested).getDataPtr(),
+            static_cast<const ColumnArray &>(*array_of_null_map).getDataPtr()),
+        static_cast<const ColumnArray &>(*array_of_nested).getOffsetsPtr());
 }


-MutableColumnPtr ColumnArray::replicateTuple(const Offsets & replicate_offsets) const
+ColumnPtr ColumnArray::replicateTuple(const Offsets & replicate_offsets) const
 {
    const ColumnTuple & tuple = static_cast<const ColumnTuple &>(*data);

@ -891,7 +894,8 @@ MutableColumnPtr ColumnArray::replicateTuple(const Offsets & replicate_offsets)

    Columns temporary_arrays(tuple_size);
    for (size_t i = 0; i < tuple_size; ++i)
-        temporary_arrays[i] = ColumnArray(tuple.getColumns()[i], getOffsetsPtr()).replicate(replicate_offsets);
+        temporary_arrays[i] = ColumnArray(tuple.getColumns()[i]->assumeMutable(), getOffsetsPtr()->assumeMutable())
+                .replicate(replicate_offsets);

    Columns tuple_columns(tuple_size);
    for (size_t i = 0; i < tuple_size; ++i)
--- a/dbms/src/Columns/ColumnArray.h
+++ b/dbms/src/Columns/ColumnArray.h
@ -24,14 +24,32 @@ private:
    friend class COWPtrHelper<IColumn, ColumnArray>;

    /** Create an array column with specified values and offsets. */
-    ColumnArray(const ColumnPtr & nested_column, const ColumnPtr & offsets_column);
+    ColumnArray(MutableColumnPtr && nested_column, MutableColumnPtr && offsets_column);

    /** Create an empty column of arrays with the type of values as in the column `nested_column` */
-    ColumnArray(const ColumnPtr & nested_column);
+    explicit ColumnArray(MutableColumnPtr && nested_column);

    ColumnArray(const ColumnArray &) = default;

 public:
+    /** Create immutable column using immutable arguments. This arguments may be shared with other columns.
+      * Use IColumn::mutate in order to make mutable column and mutate shared nested columns.
+      */
+    using Base = COWPtrHelper<IColumn, ColumnArray>;
+
+    static Ptr create(const ColumnPtr & nested_column, const ColumnPtr & offsets_column)
+    {
+        return ColumnArray::create(nested_column->assumeMutable(), offsets_column->assumeMutable());
+    }
+
+    static Ptr create(const ColumnPtr & nested_column)
+    {
+        return ColumnArray::create(nested_column->assumeMutable());
+    }
+
+    template <typename ... Args, typename = typename std::enable_if<IsMutableColumns<Args ...>::value>::type>
+    static MutablePtr create(Args &&... args) { return Base::create(std::forward<Args>(args)...); }
+
    /** On the index i there is an offset to the beginning of the i + 1 -th element. */
    using ColumnOffsets = ColumnVector<Offset>;

@ -51,15 +69,15 @@ public:
    void insertFrom(const IColumn & src_, size_t n) override;
    void insertDefault() override;
    void popBack(size_t n) override;
-    MutableColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
-    MutableColumnPtr permute(const Permutation & perm, size_t limit) const override;
+    ColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
+    ColumnPtr permute(const Permutation & perm, size_t limit) const override;
    int compareAt(size_t n, size_t m, const IColumn & rhs_, int nan_direction_hint) const override;
    void getPermutation(bool reverse, size_t limit, int nan_direction_hint, Permutation & res) const override;
    void reserve(size_t n) override;
    size_t byteSize() const override;
    size_t allocatedBytes() const override;
-    MutableColumnPtr replicate(const Offsets & replicate_offsets) const override;
-    MutableColumnPtr convertToFullColumnIfConst() const override;
+    ColumnPtr replicate(const Offsets & replicate_offsets) const override;
+    ColumnPtr convertToFullColumnIfConst() const override;
    void getExtremes(Field & min, Field & max) const override;

    bool hasEqualOffsets(const ColumnArray & other) const;
@ -110,33 +128,33 @@ private:

    /// Multiply values if the nested column is ColumnVector<T>.
    template <typename T>
-    MutableColumnPtr replicateNumber(const Offsets & replicate_offsets) const;
+    ColumnPtr replicateNumber(const Offsets & replicate_offsets) const;

    /// Multiply the values if the nested column is ColumnString. The code is too complicated.
-    MutableColumnPtr replicateString(const Offsets & replicate_offsets) const;
+    ColumnPtr replicateString(const Offsets & replicate_offsets) const;

    /** Non-constant arrays of constant values are quite rare.
      * Most functions can not work with them, and does not create such columns as a result.
      * An exception is the function `replicate`(see FunctionsMiscellaneous.h), which has service meaning for the implementation of lambda functions.
      * Only for its sake is the implementation of the `replicate` method for ColumnArray(ColumnConst).
      */
-    MutableColumnPtr replicateConst(const Offsets & replicate_offsets) const;
+    ColumnPtr replicateConst(const Offsets & replicate_offsets) const;

    /** The following is done by simply replicating of nested columns.
      */
-    MutableColumnPtr replicateTuple(const Offsets & replicate_offsets) const;
-    MutableColumnPtr replicateNullable(const Offsets & replicate_offsets) const;
-    MutableColumnPtr replicateGeneric(const Offsets & replicate_offsets) const;
+    ColumnPtr replicateTuple(const Offsets & replicate_offsets) const;
+    ColumnPtr replicateNullable(const Offsets & replicate_offsets) const;
+    ColumnPtr replicateGeneric(const Offsets & replicate_offsets) const;


    /// Specializations for the filter function.
    template <typename T>
-    MutableColumnPtr filterNumber(const Filter & filt, ssize_t result_size_hint) const;
+    ColumnPtr filterNumber(const Filter & filt, ssize_t result_size_hint) const;

-    MutableColumnPtr filterString(const Filter & filt, ssize_t result_size_hint) const;
-    MutableColumnPtr filterTuple(const Filter & filt, ssize_t result_size_hint) const;
-    MutableColumnPtr filterNullable(const Filter & filt, ssize_t result_size_hint) const;
-    MutableColumnPtr filterGeneric(const Filter & filt, ssize_t result_size_hint) const;
+    ColumnPtr filterString(const Filter & filt, ssize_t result_size_hint) const;
+    ColumnPtr filterTuple(const Filter & filt, ssize_t result_size_hint) const;
+    ColumnPtr filterNullable(const Filter & filt, ssize_t result_size_hint) const;
+    ColumnPtr filterGeneric(const Filter & filt, ssize_t result_size_hint) const;
 };


--- a/dbms/src/Columns/ColumnConst.cpp
+++ b/dbms/src/Columns/ColumnConst.cpp
@ -25,12 +25,12 @@ ColumnConst::ColumnConst(const ColumnPtr & data_, size_t s)
            ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
 }

-MutableColumnPtr ColumnConst::convertToFullColumn() const
+ColumnPtr ColumnConst::convertToFullColumn() const
 {
    return data->replicate(Offsets(1, s));
 }

-MutableColumnPtr ColumnConst::filter(const Filter & filt, ssize_t /*result_size_hint*/) const
+ColumnPtr ColumnConst::filter(const Filter & filt, ssize_t /*result_size_hint*/) const
 {
    if (s != filt.size())
        throw Exception("Size of filter (" + toString(filt.size()) + ") doesn't match size of column (" + toString(s) + ")",
@ -39,7 +39,7 @@ MutableColumnPtr ColumnConst::filter(const Filter & filt, ssize_t /*result_size_
    return ColumnConst::create(data, countBytesInFilter(filt));
 }

-MutableColumnPtr ColumnConst::replicate(const Offsets & offsets) const
+ColumnPtr ColumnConst::replicate(const Offsets & offsets) const
 {
    if (s != offsets.size())
        throw Exception("Size of offsets (" + toString(offsets.size()) + ") doesn't match size of column (" + toString(s) + ")",
@ -49,7 +49,7 @@ MutableColumnPtr ColumnConst::replicate(const Offsets & offsets) const
    return ColumnConst::create(data, replicated_size);
 }

-MutableColumnPtr ColumnConst::permute(const Permutation & perm, size_t limit) const
+ColumnPtr ColumnConst::permute(const Permutation & perm, size_t limit) const
 {
    if (limit == 0)
        limit = s;
--- a/dbms/src/Columns/ColumnConst.h
+++ b/dbms/src/Columns/ColumnConst.h
@ -29,9 +29,9 @@ private:
    ColumnConst(const ColumnConst & src) = default;

 public:
-    MutableColumnPtr convertToFullColumn() const;
+    ColumnPtr convertToFullColumn() const;

-    MutableColumnPtr convertToFullColumnIfConst() const override
+    ColumnPtr convertToFullColumnIfConst() const override
    {
        return convertToFullColumn();
    }
@ -145,9 +145,9 @@ public:
        data->updateHashWithValue(0, hash);
    }

-    MutableColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
-    MutableColumnPtr replicate(const Offsets & offsets) const override;
-    MutableColumnPtr permute(const Permutation & perm, size_t limit) const override;
+    ColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
+    ColumnPtr replicate(const Offsets & offsets) const override;
+    ColumnPtr permute(const Permutation & perm, size_t limit) const override;
    void getPermutation(bool reverse, size_t limit, int nan_direction_hint, Permutation & res) const override;

    size_t byteSize() const override
--- a/dbms/src/Columns/ColumnFixedString.cpp
+++ b/dbms/src/Columns/ColumnFixedString.cpp
@ -153,7 +153,7 @@ void ColumnFixedString::insertRangeFrom(const IColumn & src, size_t start, size_
    memcpy(&chars[old_size], &src_concrete.chars[start * n], length * n);
 }

-MutableColumnPtr ColumnFixedString::filter(const IColumn::Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnFixedString::filter(const IColumn::Filter & filt, ssize_t result_size_hint) const
 {
    size_t col_size = size();
    if (col_size != filt.size())
@ -230,7 +230,7 @@ MutableColumnPtr ColumnFixedString::filter(const IColumn::Filter & filt, ssize_t
    return std::move(res);
 }

-MutableColumnPtr ColumnFixedString::permute(const Permutation & perm, size_t limit) const
+ColumnPtr ColumnFixedString::permute(const Permutation & perm, size_t limit) const
 {
    size_t col_size = size();

@ -258,7 +258,7 @@ MutableColumnPtr ColumnFixedString::permute(const Permutation & perm, size_t lim
    return std::move(res);
 }

-MutableColumnPtr ColumnFixedString::replicate(const Offsets & offsets) const
+ColumnPtr ColumnFixedString::replicate(const Offsets & offsets) const
 {
    size_t col_size = size();
    if (col_size != offsets.size())
--- a/dbms/src/Columns/ColumnFixedString.h
+++ b/dbms/src/Columns/ColumnFixedString.h
@ -104,11 +104,11 @@ public:

    void insertRangeFrom(const IColumn & src, size_t start, size_t length) override;

-    MutableColumnPtr filter(const IColumn::Filter & filt, ssize_t result_size_hint) const override;
+    ColumnPtr filter(const IColumn::Filter & filt, ssize_t result_size_hint) const override;

-    MutableColumnPtr permute(const Permutation & perm, size_t limit) const override;
+    ColumnPtr permute(const Permutation & perm, size_t limit) const override;

-    MutableColumnPtr replicate(const Offsets & offsets) const override;
+    ColumnPtr replicate(const Offsets & offsets) const override;

    MutableColumns scatter(ColumnIndex num_columns, const Selector & selector) const override
    {
--- a/dbms/src/Columns/ColumnFunction.cpp
+++ b/dbms/src/Columns/ColumnFunction.cpp
@ -26,7 +26,7 @@ MutableColumnPtr ColumnFunction::cloneResized(size_t size) const
    return ColumnFunction::create(size, function, capture);
 }

-MutableColumnPtr ColumnFunction::replicate(const Offsets & offsets) const
+ColumnPtr ColumnFunction::replicate(const Offsets & offsets) const
 {
    if (size_ != offsets.size())
        throw Exception("Size of offsets (" + toString(offsets.size()) + ") doesn't match size of column ("
@ -40,7 +40,7 @@ MutableColumnPtr ColumnFunction::replicate(const Offsets & offsets) const
    return ColumnFunction::create(replicated_size, function, capture);
 }

-MutableColumnPtr ColumnFunction::cut(size_t start, size_t length) const
+ColumnPtr ColumnFunction::cut(size_t start, size_t length) const
 {
    ColumnsWithTypeAndName capture = captured_columns;
    for (auto & column : capture)
@ -49,7 +49,7 @@ MutableColumnPtr ColumnFunction::cut(size_t start, size_t length) const
    return ColumnFunction::create(length, function, capture);
 }

-MutableColumnPtr ColumnFunction::filter(const Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnFunction::filter(const Filter & filt, ssize_t result_size_hint) const
 {
    if (size_ != filt.size())
        throw Exception("Size of filter (" + toString(filt.size()) + ") doesn't match size of column ("
@ -68,7 +68,7 @@ MutableColumnPtr ColumnFunction::filter(const Filter & filt, ssize_t result_size
    return ColumnFunction::create(filtered_size, function, capture);
 }

-MutableColumnPtr ColumnFunction::permute(const Permutation & perm, size_t limit) const
+ColumnPtr ColumnFunction::permute(const Permutation & perm, size_t limit) const
 {
    if (limit == 0)
        limit = size_;
--- a/dbms/src/Columns/ColumnFunction.h
+++ b/dbms/src/Columns/ColumnFunction.h
@ -29,10 +29,10 @@ public:

    size_t size() const override { return size_; }

-    MutableColumnPtr cut(size_t start, size_t length) const override;
-    MutableColumnPtr replicate(const Offsets & offsets) const override;
-    MutableColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
-    MutableColumnPtr permute(const Permutation & perm, size_t limit) const override;
+    ColumnPtr cut(size_t start, size_t length) const override;
+    ColumnPtr replicate(const Offsets & offsets) const override;
+    ColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
+    ColumnPtr permute(const Permutation & perm, size_t limit) const override;
    void insertDefault() override;
    void popBack(size_t n) override;
    std::vector<MutableColumnPtr> scatter(IColumn::ColumnIndex num_columns,
--- a/dbms/src/Columns/ColumnNullable.cpp
+++ b/dbms/src/Columns/ColumnNullable.cpp
@ -18,8 +18,8 @@ namespace ErrorCodes
 }


-ColumnNullable::ColumnNullable(const ColumnPtr & nested_column_, const ColumnPtr & null_map_)
-    : nested_column{nested_column_}, null_map{null_map_}
+ColumnNullable::ColumnNullable(MutableColumnPtr && nested_column_, MutableColumnPtr && null_map_)
+    : nested_column(std::move(nested_column_)), null_map(std::move(null_map_))
 {
    /// ColumnNullable cannot have constant nested column. But constant argument could be passed. Materialize it.
    if (ColumnPtr nested_column_materialized = getNestedColumn().convertToFullColumnIfConst())
@ -44,7 +44,7 @@ void ColumnNullable::updateHashWithValue(size_t n, SipHash & hash) const

 MutableColumnPtr ColumnNullable::cloneResized(size_t new_size) const
 {
-    ColumnPtr new_nested_col = getNestedColumn().cloneResized(new_size);
+    MutableColumnPtr new_nested_col = getNestedColumn().cloneResized(new_size);
    auto new_null_map = ColumnUInt8::create();

    if (new_size > 0)
@ -59,7 +59,7 @@ MutableColumnPtr ColumnNullable::cloneResized(size_t new_size) const
            memset(&new_null_map->getData()[count], 1, new_size - count);
    }

-    return ColumnNullable::create(new_nested_col, std::move(new_null_map));
+    return ColumnNullable::create(std::move(new_nested_col), std::move(new_null_map));
 }


@ -152,14 +152,14 @@ void ColumnNullable::popBack(size_t n)
    getNullMapColumn().popBack(n);
 }

-MutableColumnPtr ColumnNullable::filter(const Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnNullable::filter(const Filter & filt, ssize_t result_size_hint) const
 {
    ColumnPtr filtered_data = getNestedColumn().filter(filt, result_size_hint);
    ColumnPtr filtered_null_map = getNullMapColumn().filter(filt, result_size_hint);
    return ColumnNullable::create(filtered_data, filtered_null_map);
 }

-MutableColumnPtr ColumnNullable::permute(const Permutation & perm, size_t limit) const
+ColumnPtr ColumnNullable::permute(const Permutation & perm, size_t limit) const
 {
    ColumnPtr permuted_data = getNestedColumn().permute(perm, limit);
    ColumnPtr permuted_null_map = getNullMapColumn().permute(perm, limit);
@ -384,7 +384,7 @@ void ColumnNullable::getExtremes(Field & min, Field & max) const
 }


-MutableColumnPtr ColumnNullable::replicate(const Offsets & offsets) const
+ColumnPtr ColumnNullable::replicate(const Offsets & offsets) const
 {
    ColumnPtr replicated_data = getNestedColumn().replicate(offsets);
    ColumnPtr replicated_null_map = getNullMapColumn().replicate(offsets);
--- a/dbms/src/Columns/ColumnNullable.h
+++ b/dbms/src/Columns/ColumnNullable.h
@ -23,10 +23,22 @@ class ColumnNullable final : public COWPtrHelper<IColumn, ColumnNullable>
 private:
    friend class COWPtrHelper<IColumn, ColumnNullable>;

-    ColumnNullable(const ColumnPtr & nested_column_, const ColumnPtr & null_map_);
+    ColumnNullable(MutableColumnPtr && nested_column_, MutableColumnPtr && null_map_);
    ColumnNullable(const ColumnNullable &) = default;

 public:
+    /** Create immutable column using immutable arguments. This arguments may be shared with other columns.
+      * Use IColumn::mutate in order to make mutable column and mutate shared nested columns.
+      */
+    using Base = COWPtrHelper<IColumn, ColumnNullable>;
+    static Ptr create(const ColumnPtr & nested_column_, const ColumnPtr & null_map_)
+    {
+        return ColumnNullable::create(nested_column_->assumeMutable(), null_map_->assumeMutable());
+    }
+
+    template <typename ... Args, typename = typename std::enable_if<IsMutableColumns<Args ...>::value>::type>
+    static MutablePtr create(Args &&... args) { return Base::create(std::forward<Args>(args)...); }
+
    const char * getFamilyName() const override { return "Nullable"; }
    std::string getName() const override { return "Nullable(" + nested_column->getName() + ")"; }
    MutableColumnPtr cloneResized(size_t size) const override;
@ -50,14 +62,14 @@ public:
    }

    void popBack(size_t n) override;
-    MutableColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
-    MutableColumnPtr permute(const Permutation & perm, size_t limit) const override;
+    ColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
+    ColumnPtr permute(const Permutation & perm, size_t limit) const override;
    int compareAt(size_t n, size_t m, const IColumn & rhs_, int null_direction_hint) const override;
    void getPermutation(bool reverse, size_t limit, int null_direction_hint, Permutation & res) const override;
    void reserve(size_t n) override;
    size_t byteSize() const override;
    size_t allocatedBytes() const override;
-    MutableColumnPtr replicate(const Offsets & replicate_offsets) const override;
+    ColumnPtr replicate(const Offsets & replicate_offsets) const override;
    void updateHashWithValue(size_t n, SipHash & hash) const override;
    void getExtremes(Field & min, Field & max) const override;

--- a/dbms/src/Columns/ColumnString.cpp
+++ b/dbms/src/Columns/ColumnString.cpp
@ -97,7 +97,7 @@ void ColumnString::insertRangeFrom(const IColumn & src, size_t start, size_t len
 }


-MutableColumnPtr ColumnString::filter(const Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnString::filter(const Filter & filt, ssize_t result_size_hint) const
 {
    if (offsets.size() == 0)
        return ColumnString::create();
@ -112,7 +112,7 @@ MutableColumnPtr ColumnString::filter(const Filter & filt, ssize_t result_size_h
 }


-MutableColumnPtr ColumnString::permute(const Permutation & perm, size_t limit) const
+ColumnPtr ColumnString::permute(const Permutation & perm, size_t limit) const
 {
    size_t size = offsets.size();

@ -208,7 +208,7 @@ void ColumnString::getPermutation(bool reverse, size_t limit, int /*nan_directio
 }


-MutableColumnPtr ColumnString::replicate(const Offsets & replicate_offsets) const
+ColumnPtr ColumnString::replicate(const Offsets & replicate_offsets) const
 {
    size_t col_size = size();
    if (col_size != replicate_offsets.size())
--- a/dbms/src/Columns/ColumnString.h
+++ b/dbms/src/Columns/ColumnString.h
@ -89,6 +89,12 @@ public:
        return StringRef(&chars[offsetAt(n)], sizeAt(n));
    }

+/// Suppress gcc 7.3.1 warning: '*((void*)&<anonymous> +8)' may be used uninitialized in this function
+#if !__clang__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+#endif
+
    void insert(const Field & x) override
    {
        const String & s = DB::get<const String &>(x);
@ -101,7 +107,11 @@ public:
        offsets.push_back(new_size);
    }

-    void insertFrom(const IColumn & src_, size_t n) override
+#if !__clang__
+#pragma GCC diagnostic pop
+#endif
+
+        void insertFrom(const IColumn & src_, size_t n) override
    {
        const ColumnString & src = static_cast<const ColumnString &>(src_);

@ -206,9 +216,9 @@ public:

    void insertRangeFrom(const IColumn & src, size_t start, size_t length) override;

-    MutableColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
+    ColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;

-    MutableColumnPtr permute(const Permutation & perm, size_t limit) const override;
+    ColumnPtr permute(const Permutation & perm, size_t limit) const override;

    void insertDefault() override
    {
@ -239,7 +249,7 @@ public:
    /// Sorting with respect of collation.
    void getPermutationWithCollation(const Collator & collator, bool reverse, size_t limit, Permutation & res) const;

-    MutableColumnPtr replicate(const Offsets & replicate_offsets) const override;
+    ColumnPtr replicate(const Offsets & replicate_offsets) const override;

    MutableColumns scatter(ColumnIndex num_columns, const Selector & selector) const override
    {
--- a/dbms/src/Columns/ColumnTuple.cpp
+++ b/dbms/src/Columns/ColumnTuple.cpp
@ -31,21 +31,38 @@ std::string ColumnTuple::getName() const
    return res.str();
 }

-ColumnTuple::ColumnTuple(const Columns & columns) : columns(columns)
+ColumnTuple::ColumnTuple(MutableColumns && mutable_columns)
+{
+    columns.reserve(mutable_columns.size());
+    for (auto & column : mutable_columns)
+    {
+        if (column->isColumnConst())
+            throw Exception{"ColumnTuple cannot have ColumnConst as its element", ErrorCodes::ILLEGAL_COLUMN};
+
+        columns.push_back(std::move(column));
+    }
+}
+
+ColumnTuple::Ptr ColumnTuple::create(const Columns & columns)
 {
    for (const auto & column : columns)
        if (column->isColumnConst())
            throw Exception{"ColumnTuple cannot have ColumnConst as its element", ErrorCodes::ILLEGAL_COLUMN};
+
+    auto column_tuple = ColumnTuple::create(MutableColumns());
+    column_tuple->columns = columns;
+
+    return std::move(column_tuple);
 }

 MutableColumnPtr ColumnTuple::cloneEmpty() const
 {
    const size_t tuple_size = columns.size();
-    Columns new_columns(tuple_size);
+    MutableColumns new_columns(tuple_size);
    for (size_t i = 0; i < tuple_size; ++i)
        new_columns[i] = columns[i]->cloneEmpty();

-    return ColumnTuple::create(new_columns);
+    return ColumnTuple::create(std::move(new_columns));
 }

 Field ColumnTuple::operator[](size_t n) const
@ -140,7 +157,7 @@ void ColumnTuple::insertRangeFrom(const IColumn & src, size_t start, size_t leng
            start, length);
 }

-MutableColumnPtr ColumnTuple::filter(const Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnTuple::filter(const Filter & filt, ssize_t result_size_hint) const
 {
    const size_t tuple_size = columns.size();
    Columns new_columns(tuple_size);
@ -151,7 +168,7 @@ MutableColumnPtr ColumnTuple::filter(const Filter & filt, ssize_t result_size_hi
    return ColumnTuple::create(new_columns);
 }

-MutableColumnPtr ColumnTuple::permute(const Permutation & perm, size_t limit) const
+ColumnPtr ColumnTuple::permute(const Permutation & perm, size_t limit) const
 {
    const size_t tuple_size = columns.size();
    Columns new_columns(tuple_size);
@ -162,7 +179,7 @@ MutableColumnPtr ColumnTuple::permute(const Permutation & perm, size_t limit) co
    return ColumnTuple::create(new_columns);
 }

-MutableColumnPtr ColumnTuple::replicate(const Offsets & offsets) const
+ColumnPtr ColumnTuple::replicate(const Offsets & offsets) const
 {
    const size_t tuple_size = columns.size();
    Columns new_columns(tuple_size);
@ -185,10 +202,10 @@ MutableColumns ColumnTuple::scatter(ColumnIndex num_columns, const Selector & se

    for (size_t scattered_idx = 0; scattered_idx < num_columns; ++scattered_idx)
    {
-        Columns new_columns(tuple_size);
+        MutableColumns new_columns(tuple_size);
        for (size_t tuple_element_idx = 0; tuple_element_idx < tuple_size; ++tuple_element_idx)
            new_columns[tuple_element_idx] = std::move(scattered_tuple_elements[tuple_element_idx][scattered_idx]);
-        res[scattered_idx] = ColumnTuple::create(new_columns);
+        res[scattered_idx] = ColumnTuple::create(std::move(new_columns));
    }

    return res;
--- a/dbms/src/Columns/ColumnTuple.h
+++ b/dbms/src/Columns/ColumnTuple.h
@ -22,10 +22,19 @@ private:
    template <bool positive>
    struct Less;

-    ColumnTuple(const Columns & columns);
+    explicit ColumnTuple(MutableColumns && columns);
    ColumnTuple(const ColumnTuple &) = default;

 public:
+    /** Create immutable column using immutable arguments. This arguments may be shared with other columns.
+      * Use IColumn::mutate in order to make mutable column and mutate shared nested columns.
+      */
+    using Base = COWPtrHelper<IColumn, ColumnTuple>;
+    static Ptr create(const Columns & columns);
+
+    template <typename Arg, typename = typename std::enable_if<std::is_rvalue_reference<Arg &&>::value>::type>
+    static MutablePtr create(Arg && arg) { return Base::create(std::forward<Arg>(arg)); }
+
    std::string getName() const override;
    const char * getFamilyName() const override { return "Tuple"; }

@ -49,9 +58,9 @@ public:
    const char * deserializeAndInsertFromArena(const char * pos) override;
    void updateHashWithValue(size_t n, SipHash & hash) const override;
    void insertRangeFrom(const IColumn & src, size_t start, size_t length) override;
-    MutableColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
-    MutableColumnPtr permute(const Permutation & perm, size_t limit) const override;
-    MutableColumnPtr replicate(const Offsets & offsets) const override;
+    ColumnPtr filter(const Filter & filt, ssize_t result_size_hint) const override;
+    ColumnPtr permute(const Permutation & perm, size_t limit) const override;
+    ColumnPtr replicate(const Offsets & offsets) const override;
    MutableColumns scatter(ColumnIndex num_columns, const Selector & selector) const override;
    void gather(ColumnGathererStream & gatherer_stream) override;
    int compareAt(size_t n, size_t m, const IColumn & rhs, int nan_direction_hint) const override;
--- a/dbms/src/Columns/ColumnVector.cpp
+++ b/dbms/src/Columns/ColumnVector.cpp
@ -146,7 +146,7 @@ void ColumnVector<T>::insertRangeFrom(const IColumn & src, size_t start, size_t
 }

 template <typename T>
-MutableColumnPtr ColumnVector<T>::filter(const IColumn::Filter & filt, ssize_t result_size_hint) const
+ColumnPtr ColumnVector<T>::filter(const IColumn::Filter & filt, ssize_t result_size_hint) const
 {
    size_t size = data.size();
    if (size != filt.size())
@ -210,7 +210,7 @@ MutableColumnPtr ColumnVector<T>::filter(const IColumn::Filter & filt, ssize_t r
 }

 template <typename T>
-MutableColumnPtr ColumnVector<T>::permute(const IColumn::Permutation & perm, size_t limit) const
+ColumnPtr ColumnVector<T>::permute(const IColumn::Permutation & perm, size_t limit) const
 {
    size_t size = data.size();

@ -231,7 +231,7 @@ MutableColumnPtr ColumnVector<T>::permute(const IColumn::Permutation & perm, siz
 }

 template <typename T>
-MutableColumnPtr ColumnVector<T>::replicate(const IColumn::Offsets & offsets) const
+ColumnPtr ColumnVector<T>::replicate(const IColumn::Offsets & offsets) const
 {
    size_t size = data.size();
    if (size != offsets.size())
--- a/dbms/src/Columns/ColumnVector.h
+++ b/dbms/src/Columns/ColumnVector.h
@ -243,11 +243,11 @@ public:

    void insertRangeFrom(const IColumn & src, size_t start, size_t length) override;

-    MutableColumnPtr filter(const IColumn::Filter & filt, ssize_t result_size_hint) const override;
+    ColumnPtr filter(const IColumn::Filter & filt, ssize_t result_size_hint) const override;

-    MutableColumnPtr permute(const IColumn::Permutation & perm, size_t limit) const override;
+    ColumnPtr permute(const IColumn::Permutation & perm, size_t limit) const override;

-    MutableColumnPtr replicate(const IColumn::Offsets & offsets) const override;
+    ColumnPtr replicate(const IColumn::Offsets & offsets) const override;

    void getExtremes(Field & min, Field & max) const override;

--- a/dbms/src/Columns/FilterDescription.cpp
+++ b/dbms/src/Columns/FilterDescription.cpp
@ -57,7 +57,8 @@ FilterDescription::FilterDescription(const IColumn & column)

    if (const ColumnNullable * nullable_column = typeid_cast<const ColumnNullable *>(&column))
    {
-        MutableColumnPtr mutable_holder = nullable_column->getNestedColumn().mutate();
+        ColumnPtr nested_column = nullable_column->getNestedColumnPtr();
+        MutableColumnPtr mutable_holder = (*std::move(nested_column)).mutate();

        ColumnUInt8 * concrete_column = typeid_cast<ColumnUInt8 *>(mutable_holder.get());
        if (!concrete_column)
--- a/dbms/src/Columns/IColumn.h
+++ b/dbms/src/Columns/IColumn.h
@ -45,7 +45,7 @@ public:
    /** If column isn't constant, returns nullptr (or itself).
      * If column is constant, transforms constant to full column (if column type allows such tranform) and return it.
      */
-    virtual MutablePtr convertToFullColumnIfConst() const { return {}; }
+    virtual Ptr convertToFullColumnIfConst() const { return {}; }

    /// Creates empty column with the same type.
    virtual MutablePtr cloneEmpty() const { return cloneResized(0); }
@ -104,11 +104,11 @@ public:

    /// Removes all elements outside of specified range.
    /// Is used in LIMIT operation, for example.
-    virtual MutablePtr cut(size_t start, size_t length) const
+    virtual Ptr cut(size_t start, size_t length) const
    {
        MutablePtr res = cloneEmpty();
        res->insertRangeFrom(*this, start, length);
-        return res;
+        return std::move(res);
    }

    /// Appends new value at the end of column (column's size is increased by 1).
@ -171,12 +171,12 @@ public:
      *  otherwise (i.e. < 0), makes reserve() using size of source column.
      */
    using Filter = PaddedPODArray<UInt8>;
-    virtual MutablePtr filter(const Filter & filt, ssize_t result_size_hint) const = 0;
+    virtual Ptr filter(const Filter & filt, ssize_t result_size_hint) const = 0;

    /// Permutes elements using specified permutation. Is used in sortings.
    /// limit - if it isn't 0, puts only first limit elements in the result.
    using Permutation = PaddedPODArray<size_t>;
-    virtual MutablePtr permute(const Permutation & perm, size_t limit) const = 0;
+    virtual Ptr permute(const Permutation & perm, size_t limit) const = 0;

    /** Compares (*this)[n] and rhs[m].
      * Returns negative number, 0, or positive number (*this)[n] is less, equal, greater than rhs[m] respectively.
@ -205,7 +205,7 @@ public:
      */
    using Offset = UInt64;
    using Offsets = PaddedPODArray<Offset>;
-    virtual MutablePtr replicate(const Offsets & offsets) const = 0;
+    virtual Ptr replicate(const Offsets & offsets) const = 0;

    /** Split column to smaller columns. Each value goes to column index, selected by corresponding element of 'selector'.
      * Selector must contain values from 0 to num_columns - 1.
@ -247,10 +247,10 @@ public:
    virtual void forEachSubcolumn(ColumnCallback) {}


-    MutablePtr mutate() const
+    MutablePtr mutate() const &&
    {
        MutablePtr res = COWPtr<IColumn>::mutate();
-        res->forEachSubcolumn([](Ptr & subcolumn) { subcolumn = subcolumn->mutate(); });
+        res->forEachSubcolumn([](Ptr & subcolumn) { subcolumn = (*std::move(subcolumn)).mutate(); });
        return res;
    }

@ -360,4 +360,16 @@ using MutableColumns = std::vector<MutableColumnPtr>;
 using ColumnRawPtrs = std::vector<const IColumn *>;
 //using MutableColumnRawPtrs = std::vector<IColumn *>;

+template <typename ... Args>
+struct IsMutableColumns;
+
+template <typename Arg, typename ... Args>
+struct IsMutableColumns<Arg, Args ...>
+{
+    static const bool value = std::is_assignable<MutableColumnPtr &&, Arg>::value && IsMutableColumns<Args ...>::value;
+};
+
+template <>
+struct IsMutableColumns<> { static const bool value = true; };
+
 }
--- a/dbms/src/Columns/IColumnDummy.h
+++ b/dbms/src/Columns/IColumnDummy.h
@ -74,12 +74,12 @@ public:
        s += length;
    }

-    MutableColumnPtr filter(const Filter & filt, ssize_t /*result_size_hint*/) const override
+    ColumnPtr filter(const Filter & filt, ssize_t /*result_size_hint*/) const override
    {
        return cloneDummy(countBytesInFilter(filt));
    }

-    MutableColumnPtr permute(const Permutation & perm, size_t limit) const override
+    ColumnPtr permute(const Permutation & perm, size_t limit) const override
    {
        if (s != perm.size())
            throw Exception("Size of permutation doesn't match size of column.", ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
@ -94,7 +94,7 @@ public:
            res[i] = i;
    }

-    MutableColumnPtr replicate(const Offsets & offsets) const override
+    ColumnPtr replicate(const Offsets & offsets) const override
    {
        if (s != offsets.size())
            throw Exception("Size of offsets doesn't match size of column.", ErrorCodes::SIZES_OF_COLUMNS_DOESNT_MATCH);
--- a/dbms/src/Common/AIO.h
+++ b/dbms/src/Common/AIO.h
@ -1,6 +1,6 @@
 #pragma once

-#if !(defined(__FreeBSD__) || defined(__APPLE__))
+#if !(defined(__FreeBSD__) || defined(__APPLE__) || defined(_MSC_VER))

 #include <Common/Exception.h>
 #include <common/logger_useful.h>
--- a/dbms/src/Common/COWPtr.h
+++ b/dbms/src/Common/COWPtr.h
@ -68,10 +68,9 @@
  * of this shared state.
  *
  * Caveats:
-  * - after a call to 'mutate' method, you can still have a reference to immutable ptr somewhere
-  *   and it can still become shared. Also it would be better to make 'mutate' method rvalue-qualified.
+  * - after a call to 'mutate' method, you can still have a reference to immutable ptr somewhere.
  * - as 'mutable_ptr' should be unique, it's refcount is redundant - probably it would be better
-  *   to use std::unique_ptr for it, but see above.
+  *   to use std::unique_ptr for it somehow.
  */
 template <typename Derived>
 class COWPtr : public boost::intrusive_ref_counter<Derived>
@ -80,12 +79,22 @@ private:
    Derived * derived() { return static_cast<Derived *>(this); }
    const Derived * derived() const { return static_cast<const Derived *>(this); }

+    template <typename T>
+    class IntrusivePtr : public boost::intrusive_ptr<T>
+    {
+    public:
+        using boost::intrusive_ptr<T>::intrusive_ptr;
+
+        T & operator*() const & { return boost::intrusive_ptr<T>::operator*(); }
+        T && operator*() const && { return const_cast<typename std::remove_const<T>::type &&>(*boost::intrusive_ptr<T>::get()); }
+    };
+
 protected:
    template <typename T>
-    class mutable_ptr : public boost::intrusive_ptr<T>
+    class mutable_ptr : public IntrusivePtr<T>
    {
    private:
-        using Base = boost::intrusive_ptr<T>;
+        using Base = IntrusivePtr<T>;

        template <typename> friend class COWPtr;
        template <typename, typename> friend class COWPtrHelper;
@ -114,10 +123,10 @@ public:

 protected:
    template <typename T>
-    class immutable_ptr : public boost::intrusive_ptr<const T>
+    class immutable_ptr : public IntrusivePtr<const T>
    {
    private:
-        using Base = boost::intrusive_ptr<const T>;
+        using Base = IntrusivePtr<const T>;

        template <typename> friend class COWPtr;
        template <typename, typename> friend class COWPtrHelper;
--- a/dbms/src/Common/Config/ConfigReloader.cpp
+++ b/dbms/src/Common/Config/ConfigReloader.cpp
@ -73,6 +73,8 @@ void ConfigReloader::run()

 void ConfigReloader::reloadIfNewer(bool force, bool throw_on_error, bool fallback_to_preprocessed)
 {
+    std::lock_guard<std::mutex> lock(reload_mutex);
+
    FilesChangesTracker new_files = getNewFileList();
    if (force || new_files.isDifferOrNewerThan(files))
    {
--- a/dbms/src/Common/Config/ConfigReloader.h
+++ b/dbms/src/Common/Config/ConfigReloader.h
@ -42,6 +42,9 @@ public:
    /// Call this method to run the backround thread.
    void start();

+    /// Reload immediately. For SYSTEM RELOAD CONFIG query.
+    void reload() { reloadIfNewer(/* force */ true, /* throw_on_error */ true, /* fallback_to_preprocessed */ false); }
+
 private:
    void run();

@ -74,6 +77,9 @@ private:

    std::atomic<bool> quit{false};
    std::thread thread;
+
+    /// Locked inside reloadIfNewer.
+    std::mutex reload_mutex;
 };

 }
--- a/dbms/src/Common/ErrorCodes.cpp
+++ b/dbms/src/Common/ErrorCodes.cpp
@ -125,7 +125,6 @@ namespace ErrorCodes
    extern const int UNKNOWN_SETTING = 115;
    extern const int THERE_IS_NO_DEFAULT_VALUE = 116;
    extern const int INCORRECT_DATA = 117;
-    extern const int TABLE_METADATA_DOESNT_EXIST = 118;
    extern const int ENGINE_REQUIRED = 119;
    extern const int CANNOT_INSERT_VALUE_OF_DIFFERENT_SIZE_INTO_TUPLE = 120;
    extern const int UNKNOWN_SET_DATA_VARIANT = 121;
@ -372,6 +371,7 @@ namespace ErrorCodes
    extern const int QUERY_WAS_CANCELLED = 394;
    extern const int FUNCTION_THROW_IF_VALUE_IS_NON_ZERO = 395;
    extern const int TOO_MANY_ROWS_OR_BYTES = 396;
+    extern const int QUERY_IS_NOT_SUPPORTED_IN_MATERIALIZED_VIEW = 397;


    extern const int KEEPER_EXCEPTION = 999;
--- a/dbms/src/Common/ExternalTable.h
+++ b/dbms/src/Common/ExternalTable.h
@ -198,7 +198,7 @@ public:

        /// Create table
        NamesAndTypesList columns = sample_block.getNamesAndTypesList();
-        StoragePtr storage = StorageMemory::create(data.second, columns, NamesAndTypesList{}, NamesAndTypesList{}, ColumnDefaults{});
+        StoragePtr storage = StorageMemory::create(data.second, ColumnsDescription{columns});
        storage->startup();
        context.addExternalTable(data.second, storage);
        BlockOutputStreamPtr output = storage->write(ASTPtr(), context.getSettingsRef());
--- a/dbms/src/Common/Macros.cpp
+++ b/dbms/src/Common/Macros.cpp
@ -1,6 +1,8 @@
+#include <Poco/Util/AbstractConfiguration.h>
 #include <Common/Macros.h>
 #include <Common/Exception.h>

+
 namespace DB
 {

--- a/dbms/src/Common/Macros.h
+++ b/dbms/src/Common/Macros.h
@ -1,10 +1,18 @@
 #pragma once

 #include <Core/Types.h>
-#include <Poco/Util/AbstractConfiguration.h>
 #include <map>


+namespace Poco
+{
+    namespace Util
+    {
+        class AbstractConfiguration;
+    }
+}
+
+
 namespace DB
 {

@ -21,10 +29,12 @@ public:
      */
    String expand(const String & s, size_t level = 0) const;

-private:
    using MacroMap = std::map<String, String>;
+    const MacroMap getMacroMap() const { return macros; }

+private:
    MacroMap macros;
 };

+
 }
--- a/dbms/src/Common/ShellCommand.cpp
+++ b/dbms/src/Common/ShellCommand.cpp
@ -1,13 +1,12 @@
 #include <sys/types.h>
 #include <sys/wait.h>
-#include <unistd.h>
 #include <fcntl.h>
 #include <dlfcn.h>
-
 #include <Common/Exception.h>
 #include <Common/ShellCommand.h>
 #include <IO/WriteBufferFromVector.h>
 #include <IO/WriteHelpers.h>
+#include <port/unistd.h>


 namespace DB
--- a/dbms/src/Common/Throttler.h
+++ b/dbms/src/Common/Throttler.h
@ -27,6 +27,9 @@ namespace ErrorCodes
 class Throttler
 {
 public:
+    Throttler(size_t max_speed_, const std::shared_ptr<Throttler> & parent = nullptr)
+            : max_speed(max_speed_), limit_exceeded_exception_message(""), parent(parent) {}
+
    Throttler(size_t max_speed_, size_t limit_, const char * limit_exceeded_exception_message_,
              const std::shared_ptr<Throttler> & parent = nullptr)
        : max_speed(max_speed_), limit(limit_), limit_exceeded_exception_message(limit_exceeded_exception_message_), parent(parent) {}
@ -76,6 +79,12 @@ public:
            parent->add(amount);
    }

+    /// Not thread safe
+    void setParent(const std::shared_ptr<Throttler> & parent_)
+    {
+        parent = parent_;
+    }
+
    void reset()
    {
        std::lock_guard lock(mutex);
--- a/dbms/src/Common/UTF8Helpers.h
+++ b/dbms/src/Common/UTF8Helpers.h
@ -3,6 +3,9 @@
 #include <Core/Types.h>
 #include <Common/BitHelpers.h>

+#if __SSE2__
+#include <emmintrin.h>
+#endif

 namespace DB
 {
@ -49,9 +52,29 @@ inline size_t seqLength(const UInt8 first_octet)
 inline size_t countCodePoints(const UInt8 * data, size_t size)
 {
    size_t res = 0;
+    const auto end = data + size;

-    /// TODO SIMD implementation looks quite simple.
-    for (auto end = data + size; data < end; ++data) /// Skip UTF-8 continuation bytes.
+#if __SSE2__
+    const auto bytes_sse = sizeof(__m128i);
+    const auto src_end_sse = (data + size) - (size % bytes_sse);
+
+    const auto align_sse = _mm_set1_epi8(0x40);
+    const auto upper_bound = _mm_set1_epi8(0xBF);
+
+    for (; data < src_end_sse; data += bytes_sse)
+    {
+        const auto chars = _mm_loadu_si128(reinterpret_cast<const __m128i *>(data));
+
+        ///Align to zero for the solve two case
+        const auto align_res = _mm_adds_epu8(chars, align_sse);
+        const auto less_than_and_equals = _mm_cmpeq_epi8(_mm_min_epu8(align_res, upper_bound), align_res);
+
+        res += __builtin_popcount(_mm_movemask_epi8(less_than_and_equals));
+    }
+
+#endif
+
+    for (; data < end; ++data) /// Skip UTF-8 continuation bytes.
        res += (*data <= 0x7F || *data >= 0xC0);

    return res;
--- a/dbms/src/Common/ZooKeeper/CMakeLists.txt
+++ b/dbms/src/Common/ZooKeeper/CMakeLists.txt
@ -5,7 +5,11 @@ add_headers_and_sources(clickhouse_common_zookeeper .)

 add_library(clickhouse_common_zookeeper ${SPLIT_SHARED} ${clickhouse_common_zookeeper_headers} ${clickhouse_common_zookeeper_sources})

-target_link_libraries (clickhouse_common_zookeeper clickhouse_common_io)
+if (NOT USE_INTERNAL_ZOOKEEPER_LIBRARY)
+    target_include_directories (clickhouse_common_zookeeper BEFORE PUBLIC ${ZOOKEEPER_INCLUDE_DIR})
+endif ()
+
+target_link_libraries (clickhouse_common_zookeeper clickhouse_common_io ${ZOOKEEPER_LIBRARY})

 if (ENABLE_TESTS)
    add_subdirectory (tests)
--- a/dbms/src/Common/ZooKeeper/KeeperException.h
+++ b/dbms/src/Common/ZooKeeper/KeeperException.h
@ -102,4 +102,19 @@ private:

 };

+
+class KeeperMultiException : public KeeperException
+{
+public:
+    MultiTransactionInfo info;
+
+    /// If it is user error throws KeeperMultiException else throws ordinary KeeperException
+    /// If it is ZOK does nothing
+    static void check(const MultiTransactionInfo & info);
+    static void check(int code, const Ops & ops, const OpResultsPtr & op_results);
+
+protected:
+    KeeperMultiException(const MultiTransactionInfo & info, size_t failed_op_index);
+};
+
 };
--- a/dbms/src/Common/ZooKeeper/Types.h
+++ b/dbms/src/Common/ZooKeeper/Types.h
@ -12,6 +12,8 @@ namespace zkutil

 using ACLPtr = const ACL_vector *;
 using Stat = ::Stat;
+class ZooKeeper;
+

 struct Op
 {
@ -19,7 +21,7 @@ public:
    Op() : data(new zoo_op_t) {}
    virtual ~Op() {}

-    virtual std::unique_ptr<Op> clone() const = 0;
+    virtual std::shared_ptr<Op> clone() const = 0;

    virtual std::string getPath() const = 0;

@ -33,6 +35,9 @@ public:
    struct Check;
 };

+using OpPtr = std::shared_ptr<Op>;
+
+
 struct Op::Remove : public Op
 {
    Remove(const std::string & path_, int32_t version_) :
@ -41,9 +46,9 @@ struct Op::Remove : public Op
        zoo_delete_op_init(data.get(), path.c_str(), version);
    }

-    std::unique_ptr<Op> clone() const override
+    OpPtr clone() const override
    {
-        return std::unique_ptr<zkutil::Op>(new Remove(path, version));
+        return std::make_shared<Remove>(path, version);
    }

    std::string getPath() const override { return path; }
@ -59,9 +64,9 @@ struct Op::Create : public Op
 {
    Create(const std::string & path_pattern_, const std::string & value_, ACLPtr acl_, int32_t flags_);

-    std::unique_ptr<Op> clone() const override
+    OpPtr clone() const override
    {
-        return std::unique_ptr<zkutil::Op>(new Create(path_pattern, value, acl, flags));
+        return std::make_shared<Create>(path_pattern, value, acl, flags);
    }

    std::string getPathCreated() { return created_path.data(); }
@ -91,9 +96,9 @@ struct Op::SetData : public Op
        zoo_set_op_init(data.get(), path.c_str(), value.c_str(), value.size(), version, &stat);
    }

-    std::unique_ptr<Op> clone() const override
+    OpPtr clone() const override
    {
-        return std::unique_ptr<zkutil::Op>(new SetData(path, value, version));
+        return std::make_shared<SetData>(path, value, version);
    }

    std::string getPath() const override { return path; }
@ -122,9 +127,9 @@ struct Op::Check : public Op
        zoo_check_op_init(data.get(), path.c_str(), version);
    }

-    std::unique_ptr<Op> clone() const override
+    OpPtr clone() const override
    {
-        return std::unique_ptr<zkutil::Op>(new Check(path, version));
+        return std::make_shared<Check>(path, version);
    }

    std::string getPath() const override { return path; }
@ -136,18 +141,46 @@ private:
    int32_t version;
 };

-struct OpResult : public zoo_op_result_t
-{
-    /// Pointers in this class point to fields of class Op.
-    /// Op instances have the same (or longer lifetime), therefore destructor is not required.
-};
-
-using OpPtr = std::unique_ptr<Op>;
 using Ops = std::vector<OpPtr>;
+
+
+/// C++ version of zoo_op_result_t
+struct OpResult
+{
+    int err;
+    std::string value;
+    std::unique_ptr<Stat> stat;
+
+    /// ZooKeeper is required for correct chroot path prefixes handling
+    explicit OpResult(const zoo_op_result_t & op_result, const ZooKeeper * zookeeper = nullptr);
+};
 using OpResults = std::vector<OpResult>;
 using OpResultsPtr = std::shared_ptr<OpResults>;
 using Strings = std::vector<std::string>;

+
+/// Simple structure to handle transaction execution results
+struct MultiTransactionInfo
+{
+    Ops ops;
+    int32_t code = ZOK;
+    OpResultsPtr op_results;
+
+    MultiTransactionInfo() = default;
+
+    MultiTransactionInfo(int32_t code_, const Ops & ops_, const OpResultsPtr & op_results_)
+        : ops(ops_), code(code_), op_results(op_results_) {}
+
+    bool empty() const
+    {
+        return ops.empty();
+    }
+
+    /// Returns failed op if zkutil::isUserError(code) is true
+    const Op & getFailedOp() const;
+};
+
+
 namespace CreateMode
 {
    extern const int Persistent;
--- a/dbms/src/Common/ZooKeeper/ZooKeeper.cpp
+++ b/dbms/src/Common/ZooKeeper/ZooKeeper.cpp
@ -82,19 +82,21 @@ void ZooKeeper::processCallback(zhandle_t *, int type, int state, const char * p
 }

 void ZooKeeper::init(const std::string & hosts_, const std::string & identity_,
-                     int32_t session_timeout_ms_, bool check_root_exists)
+                     int32_t session_timeout_ms_, const std::string & chroot_)
 {
    log = &Logger::get("ZooKeeper");
    zoo_set_debug_level(ZOO_LOG_LEVEL_ERROR);
    hosts = hosts_;
    identity = identity_;
    session_timeout_ms = session_timeout_ms_;
+    chroot = chroot_;

-    impl = zookeeper_init(hosts.c_str(), nullptr, session_timeout_ms, nullptr, nullptr, 0);
+    std::string hosts_for_lib = hosts + chroot;
+    impl = zookeeper_init(hosts_for_lib.c_str(), nullptr, session_timeout_ms, nullptr, nullptr, 0);
    ProfileEvents::increment(ProfileEvents::ZooKeeperInit);

    if (!impl)
-        throw KeeperException("Fail to initialize zookeeper. Hosts are " + hosts);
+        throw KeeperException("Fail to initialize zookeeper. Hosts are " + hosts_for_lib);

    if (!identity.empty())
    {
@ -107,16 +109,16 @@ void ZooKeeper::init(const std::string & hosts_, const std::string & identity_,
    else
        default_acl = &ZOO_OPEN_ACL_UNSAFE;

-    LOG_TRACE(log, "initialized, hosts: " << hosts);
+    LOG_TRACE(log, "initialized, hosts: " << hosts << (chroot.empty() ? "" : ", chroot: " + chroot));

-    if (check_root_exists && !exists("/"))
-        throw KeeperException("Zookeeper root doesn't exist. You should create root node before start.");
+    if (!chroot.empty() && !exists("/"))
+        throw KeeperException("Zookeeper root doesn't exist. You should create root node " + chroot + " before start.");
 }

 ZooKeeper::ZooKeeper(const std::string & hosts, const std::string & identity,
-                     int32_t session_timeout_ms, bool check_root_exists)
+                     int32_t session_timeout_ms, const std::string & chroot)
 {
-    init(hosts, identity, session_timeout_ms, check_root_exists);
+    init(hosts, identity, session_timeout_ms, chroot);
 }

 struct ZooKeeperArgs
@ -127,10 +129,8 @@ struct ZooKeeperArgs
        config.keys(config_name, keys);

        std::vector<std::string> hosts_strings;
-        std::string root;

        session_timeout_ms = DEFAULT_SESSION_TIMEOUT;
-        has_chroot = false;
        for (const auto & key : keys)
        {
            if (startsWith(key, "node"))
@ -150,7 +150,7 @@ struct ZooKeeperArgs
            }
            else if (key == "root")
            {
-                root = config.getString(config_name + "." + key);
+                chroot = config.getString(config_name + "." + key);
            }
            else throw KeeperException(std::string("Unknown key ") + key + " in config file");
        }
@ -166,28 +166,25 @@ struct ZooKeeperArgs
            hosts += host;
        }

-        if (!root.empty())
+        if (!chroot.empty())
        {
-            if (root.front() != '/')
-                throw KeeperException(std::string("Root path in config file should start with '/', but got ") + root);
-            if (root.back() == '/')
-                root.pop_back();
-
-            hosts += root;
-            has_chroot = true;
+            if (chroot.front() != '/')
+                throw KeeperException(std::string("Root path in config file should start with '/', but got ") + chroot);
+            if (chroot.back() == '/')
+                chroot.pop_back();
        }
    }

    std::string hosts;
    std::string identity;
    int session_timeout_ms;
-    bool has_chroot;
+    std::string chroot;
 };

 ZooKeeper::ZooKeeper(const Poco::Util::AbstractConfiguration & config, const std::string & config_name)
 {
    ZooKeeperArgs args(config, config_name);
-    init(args.hosts, args.identity, args.session_timeout_ms, args.has_chroot);
+    init(args.hosts, args.identity, args.session_timeout_ms, args.chroot);
 }

 WatchCallback ZooKeeper::callbackForEvent(const EventPtr & event)
@ -290,19 +287,18 @@ int32_t ZooKeeper::createImpl(const std::string & path, const std::string & data
    int code;
    /// The name of the created node can be longer than path if the sequential node is created.
    size_t name_buffer_size = path.size() + SEQUENTIAL_SUFFIX_SIZE;
-    char * name_buffer = new char[name_buffer_size];
+    std::string name_buffer(name_buffer_size, '\0');

-    code = zoo_create(impl, path.c_str(), data.c_str(), data.size(), getDefaultACL(), mode,  name_buffer, name_buffer_size);
+    code = zoo_create(impl, path.c_str(), data.c_str(), data.size(), getDefaultACL(), mode,  name_buffer.data(), name_buffer_size);
    ProfileEvents::increment(ProfileEvents::ZooKeeperCreate);
    ProfileEvents::increment(ProfileEvents::ZooKeeperTransactions);

    if (code == ZOK)
    {
-        path_created = std::string(name_buffer);
+        name_buffer.resize(strlen(name_buffer.data()));
+        path_created = std::move(name_buffer);
    }

-    delete[] name_buffer;
-
    return code;
 }

@ -571,7 +567,19 @@ int32_t ZooKeeper::trySet(const std::string & path, const std::string & data,
    return code;
 }

-int32_t ZooKeeper::multiImpl(const Ops & ops_, OpResultsPtr * out_results_)
+/// Makes deep copy of zoo_op_result_t and removes chroot prefix from paths
+static void convertOpResults(const std::vector<zoo_op_result_t> & op_results_native, OpResultsPtr & out_op_results,
+                             const ZooKeeper * zookeeper = nullptr)
+{
+    if (!out_op_results)
+        out_op_results = std::make_shared<OpResults>();
+
+    out_op_results->reserve(op_results_native.size());
+    for (const zoo_op_result_t & res_native : op_results_native)
+        out_op_results->emplace_back(res_native, zookeeper);
+}
+
+int32_t ZooKeeper::multiImpl(const Ops & ops_, OpResultsPtr * out_op_results, MultiTransactionInfo * out_info)
 {
    if (ops_.empty())
        return ZOK;
@ -585,7 +593,7 @@ int32_t ZooKeeper::multiImpl(const Ops & ops_, OpResultsPtr * out_results_)
        return ZINVALIDSTATE;

    size_t count = ops_.size();
-    OpResultsPtr out_results(new OpResults(count));
+    std::vector<zoo_op_result_t> out_results_native(count);

    /// Copy the struct containing pointers with default copy-constructor.
    /// It is safe because it hasn't got a destructor.
@ -594,34 +602,31 @@ int32_t ZooKeeper::multiImpl(const Ops & ops_, OpResultsPtr * out_results_)
    for (const auto & op : ops_)
        ops.push_back(*(op->data));

-    int32_t code = zoo_multi(impl, static_cast<int>(ops.size()), ops.data(), out_results->data());
+    int32_t code = zoo_multi(impl, static_cast<int>(ops.size()), ops.data(), out_results_native.data());
    ProfileEvents::increment(ProfileEvents::ZooKeeperMulti);
    ProfileEvents::increment(ProfileEvents::ZooKeeperTransactions);

-    if (out_results_)
-        *out_results_ = out_results;
+    if (out_op_results || out_info)
+    {
+        OpResultsPtr op_results;
+        convertOpResults(out_results_native, op_results, this);
+
+        if (out_op_results)
+            *out_op_results = op_results;
+
+        if (out_info)
+            *out_info = MultiTransactionInfo(code, ops_, op_results);
+    }

    return code;
 }

 OpResultsPtr ZooKeeper::multi(const Ops & ops)
 {
-    OpResultsPtr results;
-    int code = tryMulti(ops, &results);
-    if (code != ZOK)
-    {
-        if (results && results->size() == ops.size())
-        {
-            for (size_t i = 0; i < ops.size(); ++i)
-            {
-                if (results->at(i).err == code)
-                    throw KeeperException("Transaction failed at op #" + std::to_string(i) + ": " + ops[i]->describe(), code);
-            }
-        }
-
-        throw KeeperException(code);
-    }
-    return results;
+    OpResultsPtr op_results;
+    int code = multiImpl(ops, &op_results);
+    KeeperMultiException::check(code, ops, op_results);
+    return op_results;
 }

 int32_t ZooKeeper::tryMulti(const Ops & ops_, OpResultsPtr * out_results_)
@ -638,17 +643,9 @@ int32_t ZooKeeper::tryMulti(const Ops & ops_, OpResultsPtr * out_results_)
    return code;
 }

-int32_t ZooKeeper::tryMultiUnsafe(const Ops & ops, MultiTransactionInfo & info)
-{
-    info.code = multiImpl(ops, &info.op_results);
-    for (const OpPtr & op : ops)
-        info.ops.emplace_back(op->clone());
-    return info.code;
-}
-
 int32_t ZooKeeper::tryMultiWithRetries(const Ops & ops, OpResultsPtr * out_results, size_t * attempt)
 {
-    int32_t code = retry(std::bind(&ZooKeeper::multiImpl, this, std::ref(ops), out_results), attempt);
+    int32_t code = retry(std::bind(&ZooKeeper::multiImpl, this, std::ref(ops), out_results, nullptr), attempt);
    if (!(code == ZOK ||
        code == ZNONODE ||
        code == ZNODEEXISTS ||
@ -754,7 +751,7 @@ ZooKeeper::~ZooKeeper()

 ZooKeeperPtr ZooKeeper::startNewSession() const
 {
-    return std::make_shared<ZooKeeper>(hosts, identity, session_timeout_ms);
+    return std::make_shared<ZooKeeper>(hosts, identity, session_timeout_ms, chroot);
 }

 Op::Create::Create(const std::string & path_pattern_, const std::string & value_, ACLPtr acl_, int32_t flags_)
@ -981,26 +978,27 @@ ZooKeeper::TryRemoveFuture ZooKeeper::asyncTryRemove(const std::string & path, i

 ZooKeeper::MultiFuture ZooKeeper::asyncMultiImpl(const zkutil::Ops & ops_, bool throw_exception)
 {
-    size_t count = ops_.size();
-    OpResultsPtr results(new OpResults(count));
-
    /// We need to hold all references to ops data until the end of multi callback
    struct OpsHolder
    {
-        std::shared_ptr<zkutil::Ops> ops_ptr = std::make_shared<zkutil::Ops>();
-        std::shared_ptr<std::vector<zoo_op_t>> ops_raw_ptr = std::make_shared<std::vector<zoo_op_t>>();
+        std::shared_ptr<zkutil::Ops> ops_ptr;
+        std::shared_ptr<std::vector<zoo_op_t>> ops_native;
+        std::shared_ptr<std::vector<zoo_op_result_t>> op_results_native;
    } holder;

-    for (const auto & op : ops_)
-    {
-        holder.ops_ptr->emplace_back(op->clone());
-        holder.ops_raw_ptr->push_back(*holder.ops_ptr->back()->data);
-    }
+    /// Copy ops (swallow copy)
+    holder.ops_ptr = std::make_shared<zkutil::Ops>(ops_);
+    /// Copy native ops to contiguous vector
+    holder.ops_native = std::make_shared<std::vector<zoo_op_t>>();
+    for (const OpPtr & op : *holder.ops_ptr)
+        holder.ops_native->push_back(*op->data);
+    /// Allocate native result holders
+    holder.op_results_native = std::make_shared<std::vector<zoo_op_result_t>>(holder.ops_ptr->size());

-    MultiFuture future{ [throw_exception, results, holder] (int rc) {
+    MultiFuture future{ [throw_exception, holder, zookeeper=this] (int rc) {
        OpResultsAndCode res;
        res.code = rc;
-        res.results = results;
+        convertOpResults(*holder.op_results_native, res.results, zookeeper);
        res.ops_ptr = holder.ops_ptr;
        if (throw_exception && rc != ZOK)
            throw zkutil::KeeperException(rc);
@ -1018,9 +1016,9 @@ ZooKeeper::MultiFuture ZooKeeper::asyncMultiImpl(const zkutil::Ops & ops_, bool
    if (expired())
        throw KeeperException(ZINVALIDSTATE);

-    auto & ops = *holder.ops_raw_ptr;
-
-    int32_t code = zoo_amulti(impl, static_cast<int>(ops.size()), ops.data(), results->data(),
+    int32_t code = zoo_amulti(impl, static_cast<int>(holder.ops_native->size()),
+                              holder.ops_native->data(),
+                              holder.op_results_native->data(),
                              [] (int rc, const void * data)
                              {
                                  MultiFuture::TaskPtr owned_task =
@ -1069,4 +1067,58 @@ size_t getFailedOpIndex(const OpResultsPtr & op_results, int32_t transaction_ret
 }


+OpResult::OpResult(const zoo_op_result_t & op_result, const ZooKeeper * zookeeper)
+    : err(op_result.err)
+{
+    if (op_result.value)
+    {
+        value = std::string(op_result.value, op_result.value + op_result.valuelen);
+
+        /// Current version of libzookeeper does not cut chroot path prefixes
+        /// We do it here manually
+        if (zookeeper && !zookeeper->chroot.empty())
+        {
+            if (startsWith(value, zookeeper->chroot))
+                value = value.substr(zookeeper->chroot.length());
+            else
+                throw DB::Exception("Expected ZooKeeper path with chroot " + zookeeper->chroot + ", got " + value,
+                                    DB::ErrorCodes::LOGICAL_ERROR);
+        }
+    }
+
+    if (op_result.stat)
+        stat = std::make_unique<Stat>(*op_result.stat);
+}
+
+
+KeeperMultiException::KeeperMultiException(const MultiTransactionInfo & info_, size_t failed_op_index_)
+    :KeeperException(
+        "Transaction failed at op #" + std::to_string(failed_op_index_) + ": " + info_.ops.at(failed_op_index_)->describe(),
+        info_.code),
+    info(info_) {}
+
+void KeeperMultiException::check(int code, const Ops & ops, const OpResultsPtr & op_results)
+{
+    if (code == ZOK) {}
+    else if (zkutil::isUserError(code))
+        throw KeeperMultiException(MultiTransactionInfo(code, ops, op_results), getFailedOpIndex(op_results, code));
+    else
+        throw KeeperException(code);
+}
+
+void KeeperMultiException::check(const MultiTransactionInfo & info)
+{
+    if (info.code == ZOK) {}
+    else if (zkutil::isUserError(info.code))
+        throw KeeperMultiException(info, getFailedOpIndex(info.op_results, info.code));
+    else
+        throw KeeperException(info.code);
+}
+
+
+const Op & MultiTransactionInfo::getFailedOp() const
+{
+    return *ops.at(getFailedOpIndex(op_results, code));
+}
+
 }
--- a/dbms/src/Common/ZooKeeper/ZooKeeper.h
+++ b/dbms/src/Common/ZooKeeper/ZooKeeper.h
@ -8,10 +8,10 @@
 #include <memory>
 #include <mutex>
 #include <string>
-#include <unistd.h>
 #include <common/logger_useful.h>
 #include <Common/ProfileEvents.h>
 #include <Common/CurrentMetrics.h>
+#include <port/unistd.h>


 namespace ProfileEvents
@ -56,7 +56,7 @@ public:
    using Ptr = std::shared_ptr<ZooKeeper>;

    ZooKeeper(const std::string & hosts, const std::string & identity = "",
-              int32_t session_timeout_ms = DEFAULT_SESSION_TIMEOUT, bool check_root_exists = false);
+              int32_t session_timeout_ms = DEFAULT_SESSION_TIMEOUT, const std::string & chroot = "");

    /** Config of the form:
        <zookeeper>
@ -196,14 +196,16 @@ public:
    /// Performs several operations in a transaction.
    /// Throws on every error.
    OpResultsPtr multi(const Ops & ops);
-
    /// Throws only if some operation has returned an "unexpected" error
    /// - an error that would cause the corresponding try- method to throw.
    int32_t tryMulti(const Ops & ops, OpResultsPtr * out_results = nullptr);
-    /// Like previous one, but does not throw any ZooKeeper exceptions
-    int32_t tryMultiUnsafe(const Ops & ops, MultiTransactionInfo & info);
    /// Use only with read-only operations.
    int32_t tryMultiWithRetries(const Ops & ops, OpResultsPtr * out_results = nullptr, size_t * attempt = nullptr);
+    /// Throws nothing, just alias of multiImpl
+    int32_t tryMultiNoThrow(const Ops & ops, OpResultsPtr * out_op_results = nullptr, MultiTransactionInfo * out_info = nullptr)
+    {
+        return multiImpl(ops, out_op_results, out_info);
+    }

    Int64 getClientID();

@ -366,9 +368,10 @@ public:
 private:
    friend struct WatchContext;
    friend class EphemeralNodeHolder;
+    friend struct OpResult;
+
+    void init(const std::string & hosts, const std::string & identity, int32_t session_timeout_ms, const std::string & chroot);

-    void init(const std::string & hosts, const std::string & identity,
-              int32_t session_timeout_ms, bool check_root_exists);
    void removeChildrenRecursive(const std::string & path);
    void tryRemoveChildrenRecursive(const std::string & path);

@ -391,7 +394,7 @@ private:
            /// If the connection has been lost, wait timeout/3 hoping for connection re-establishment.
            static const int MAX_SLEEP_TIME = 10;
            if (code == ZCONNECTIONLOSS)
-                usleep(std::min(session_timeout_ms * 1000 / 3, MAX_SLEEP_TIME * 1000 * 1000));
+                usleep(std::min(session_timeout_ms * 1000u / 3, MAX_SLEEP_TIME * 1000u * 1000u));

            LOG_WARNING(log, "Error on attempt " << i << ": " << error2string(code)  << ". Retry");
            code = operation();
@ -406,7 +409,7 @@ private:
    int32_t getImpl(const std::string & path, std::string & res, Stat * stat, WatchCallback watch_callback);
    int32_t setImpl(const std::string & path, const std::string & data, int32_t version = -1, Stat * stat = nullptr);
    int32_t getChildrenImpl(const std::string & path, Strings & res, Stat * stat, WatchCallback watch_callback);
-    int32_t multiImpl(const Ops & ops, OpResultsPtr * out_results = nullptr);
+    int32_t multiImpl(const Ops & ops, OpResultsPtr * out_op_results = nullptr, MultiTransactionInfo * out_info = nullptr);
    int32_t existsImpl(const std::string & path, Stat * stat_, WatchCallback watch_callback);

    MultiFuture asyncMultiImpl(const zkutil::Ops & ops_, bool throw_exception);
@ -414,6 +417,7 @@ private:
    std::string hosts;
    std::string identity;
    int32_t session_timeout_ms;
+    std::string chroot;

    std::mutex mutex;
    ACLPtr default_acl;
@ -493,41 +497,4 @@ private:

 using EphemeralNodeHolderPtr = EphemeralNodeHolder::Ptr;

-
-/// Simple structure to handle transaction execution results
-struct MultiTransactionInfo
-{
-    MultiTransactionInfo() = default;
-
-    Ops ops;
-    int32_t code = ZOK;
-    OpResultsPtr op_results;
-
-    bool empty() const
-    {
-        return ops.empty();
-    }
-
-    bool hasFailedOp() const
-    {
-        return zkutil::isUserError(code);
-    }
-
-    const Op & getFailedOp() const
-    {
-        return *ops.at(getFailedOpIndex(op_results, code));
-    }
-
-    KeeperException getException() const
-    {
-        if (hasFailedOp())
-        {
-            size_t i = getFailedOpIndex(op_results, code);
-            return KeeperException("Transaction failed at op #" + std::to_string(i) + ": " + ops.at(i)->describe(), code);
-        }
-        else
-            return KeeperException(code);
-    }
-};
-
 }
--- a/dbms/src/Common/ZooKeeper/tests/gtest_zkutil_test_multi_exception.cpp
+++ b/dbms/src/Common/ZooKeeper/tests/gtest_zkutil_test_multi_exception.cpp
@ -6,6 +6,9 @@
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wsign-compare"
 #include <gtest/gtest.h>
+#include <Common/ShellCommand.h>
+
+
 #pragma GCC diagnostic pop

 using namespace DB;
@ -32,32 +35,32 @@ TEST(zkutil, multi_nice_exception_msg)
    zkutil::Ops ops;

    ASSERT_NO_THROW(
-        zookeeper->tryRemoveRecursive("/clickhouse_test_zkutil_multi");
+        zookeeper->tryRemoveRecursive("/clickhouse_test/zkutil_multi");

-        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi", "_", acl, zkutil::CreateMode::Persistent));
-        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi/a", "_", acl, zkutil::CreateMode::Persistent));
+        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi", "_", acl, zkutil::CreateMode::Persistent));
+        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi/a", "_", acl, zkutil::CreateMode::Persistent));
        zookeeper->multi(ops);
    );

    try
    {
        ops.clear();
-        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi/c", "_", acl, zkutil::CreateMode::Persistent));
-        ops.emplace_back(new zkutil::Op::Remove("/clickhouse_test_zkutil_multi/c", -1));
-        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi/a", "BadBoy", acl, zkutil::CreateMode::Persistent));
-        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi/b", "_", acl, zkutil::CreateMode::Persistent));
-        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi/a", "_", acl, zkutil::CreateMode::Persistent));
+        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi/c", "_", acl, zkutil::CreateMode::Persistent));
+        ops.emplace_back(new zkutil::Op::Remove("/clickhouse_test/zkutil_multi/c", -1));
+        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi/a", "BadBoy", acl, zkutil::CreateMode::Persistent));
+        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi/b", "_", acl, zkutil::CreateMode::Persistent));
+        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi/a", "_", acl, zkutil::CreateMode::Persistent));

        zookeeper->multi(ops);
        FAIL();
    }
    catch (...)
    {
-        zookeeper->tryRemoveRecursive("/clickhouse_test_zkutil_multi");
+        zookeeper->tryRemoveRecursive("/clickhouse_test/zkutil_multi");

        String msg = getCurrentExceptionMessage(false);

-        bool msg_has_reqired_patterns = msg.find("/clickhouse_test_zkutil_multi/a") != std::string::npos && msg.find("#2") != std::string::npos;
+        bool msg_has_reqired_patterns = msg.find("/clickhouse_test/zkutil_multi/a") != std::string::npos && msg.find("#2") != std::string::npos;
        EXPECT_TRUE(msg_has_reqired_patterns) << msg;
    }
 }
@ -69,7 +72,7 @@ TEST(zkutil, multi_async)
    auto acl = zookeeper->getDefaultACL();
    zkutil::Ops ops;

-    zookeeper->tryRemoveRecursive("/clickhouse_test_zkutil_multi");
+    zookeeper->tryRemoveRecursive("/clickhouse_test/zkutil_multi");

    {
        ops.clear();
@ -78,8 +81,8 @@ TEST(zkutil, multi_async)

    {
        ops.clear();
-        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi", "", acl, zkutil::CreateMode::Persistent));
-        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi/a", "", acl, zkutil::CreateMode::Persistent));
+        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi", "", acl, zkutil::CreateMode::Persistent));
+        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi/a", "", acl, zkutil::CreateMode::Persistent));

        auto fut = zookeeper->tryAsyncMulti(ops);
        ops.clear();
@ -97,11 +100,11 @@ TEST(zkutil, multi_async)
        for (size_t i = 0; i < 10000; ++i)
        {
            ops.clear();
-            ops.emplace_back(new zkutil::Op::Remove("/clickhouse_test_zkutil_multi", -1));
-            ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi", "_", acl, zkutil::CreateMode::Persistent));
-            ops.emplace_back(new zkutil::Op::Check("/clickhouse_test_zkutil_multi", -1));
-            ops.emplace_back(new zkutil::Op::SetData("/clickhouse_test_zkutil_multi", "xxx", 42));
-            ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi/a", "_", acl, zkutil::CreateMode::Persistent));
+            ops.emplace_back(new zkutil::Op::Remove("/clickhouse_test/zkutil_multi", -1));
+            ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi", "_", acl, zkutil::CreateMode::Persistent));
+            ops.emplace_back(new zkutil::Op::Check("/clickhouse_test/zkutil_multi", -1));
+            ops.emplace_back(new zkutil::Op::SetData("/clickhouse_test/zkutil_multi", "xxx", 42));
+            ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi/a", "_", acl, zkutil::CreateMode::Persistent));

            futures.emplace_back(zookeeper->asyncMulti(ops));
        }
@ -115,8 +118,8 @@ TEST(zkutil, multi_async)

    {
        ops.clear();
-        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi", "_", acl, zkutil::CreateMode::Persistent));
-        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test_zkutil_multi/a", "_", acl, zkutil::CreateMode::Persistent));
+        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi", "_", acl, zkutil::CreateMode::Persistent));
+        ops.emplace_back(new zkutil::Op::Create("/clickhouse_test/zkutil_multi/a", "_", acl, zkutil::CreateMode::Persistent));

        auto fut = zookeeper->tryAsyncMulti(ops);
        ops.clear();
@ -128,31 +131,55 @@ TEST(zkutil, multi_async)
    }
 }

+/// Run this test under sudo
+TEST(zkutil, multi_async_libzookeeper_segfault)
+{
+    auto zookeeper = std::make_unique<zkutil::ZooKeeper>("localhost:2181", "", 1000);
+    zkutil::Ops ops;
+
+    ops.emplace_back(new zkutil::Op::Check("/clickhouse_test/zkutil_multi", 0));
+
+    /// Uncomment to test
+    //auto cmd = ShellCommand::execute("sudo service zookeeper restart");
+    //cmd->wait();
+
+    auto future = zookeeper->asyncMulti(ops);
+    auto res = future.get();
+
+    EXPECT_TRUE(zkutil::isUnrecoverableErrorCode(res.code));
+}
+

 TEST(zkutil, multi_create_sequential)
 {
    try
    {
+        /// Create chroot node firstly
        auto zookeeper = std::make_unique<zkutil::ZooKeeper>("localhost:2181");
+        zookeeper->createAncestors("/clickhouse_test/");
+
+        zookeeper = std::make_unique<zkutil::ZooKeeper>("localhost:2181", "", zkutil::DEFAULT_SESSION_TIMEOUT, "/clickhouse_test");
        auto acl = zookeeper->getDefaultACL();
        zkutil::Ops ops;

-        String base_path = "/clickhouse_test/zkutil/multi_create_sequential";
+        String base_path = "/zkutil/multi_create_sequential";
        zookeeper->tryRemoveRecursive(base_path);
        zookeeper->createAncestors(base_path + "/");

-        String entry_path = base_path + "/queue-";
-        ops.emplace_back(new zkutil::Op::Create(entry_path, "", acl, zkutil::CreateMode::EphemeralSequential));
+        String sequential_node_prefix = base_path + "/queue-";
+        ops.emplace_back(new zkutil::Op::Create(sequential_node_prefix, "", acl, zkutil::CreateMode::EphemeralSequential));
        zkutil::OpResultsPtr results = zookeeper->multi(ops);
-        zkutil::OpResult & result = results->at(0);
+        zkutil::OpResult & sequential_node_result_op = results->at(0);

-        EXPECT_TRUE(result.value != nullptr);
-        EXPECT_TRUE(startsWith(result.value, entry_path));
+        EXPECT_FALSE(sequential_node_result_op.value.empty());
+        EXPECT_GT(sequential_node_result_op.value.length(), sequential_node_prefix.length());
+        EXPECT_EQ(sequential_node_result_op.value.substr(0, sequential_node_prefix.length()), sequential_node_prefix);
    }
    catch (...)
    {
        std::cerr << getCurrentExceptionMessage(false);
        throw;
    }
-
 }
+
+
--- a/dbms/src/Common/ZooKeeper/tests/zkutil_expiration_test.cpp
+++ b/dbms/src/Common/ZooKeeper/tests/zkutil_expiration_test.cpp
@ -34,11 +34,11 @@ int main(int argc, char ** argv)
        {
            {
                zkutil::Ops ops;
-                ops.emplace_back(std::make_unique<zkutil::Op::Create>("/test/zk_expiration_test", "hello", zk.getDefaultACL(), zkutil::CreateMode::Persistent));
-                ops.emplace_back(std::make_unique<zkutil::Op::Remove>("/test/zk_expiration_test", -1));
+                ops.emplace_back(std::make_shared<zkutil::Op::Create>("/test/zk_expiration_test", "hello", zk.getDefaultACL(), zkutil::CreateMode::Persistent));
+                ops.emplace_back(std::make_shared<zkutil::Op::Remove>("/test/zk_expiration_test", -1));

                zkutil::MultiTransactionInfo info;
-                zk.tryMultiUnsafe(ops, info);
+                zk.tryMultiNoThrow(ops, nullptr, &info);

                std::cout << time(nullptr) - time0 << "s: " << zkutil::ZooKeeper::error2string(info.code) << std::endl;
                try
--- a/dbms/src/Common/ZooKeeper/tests/zkutil_test_commands.cpp
+++ b/dbms/src/Common/ZooKeeper/tests/zkutil_test_commands.cpp
@ -1,6 +1,6 @@
 #include <Common/ZooKeeper/ZooKeeper.h>
 #include <iostream>
-#include <unistd.h>
+#include <port/unistd.h>

 using namespace zkutil;

--- a/dbms/src/Common/isLocalAddress.h
+++ b/dbms/src/Common/isLocalAddress.h
@ -12,7 +12,6 @@ namespace Poco

 namespace DB
 {
-
    /** Lets you check if the address is similar to `localhost`.
     * The purpose of this check is usually to make an assumption,
     *  that when we go to this address via the Internet, we'll get to ourselves.
--- a/dbms/src/Common/localBackup.cpp
+++ b/dbms/src/Common/localBackup.cpp
@ -1,13 +1,10 @@
 #include <sys/stat.h>
-#include <unistd.h>
-
 #include <string>
 #include <iostream>
-
 #include <Poco/DirectoryIterator.h>
 #include <Poco/File.h>
-
 #include <Common/Exception.h>
+#include <port/unistd.h>


 namespace DB
--- a/dbms/src/Common/randomSeed.cpp
+++ b/dbms/src/Common/randomSeed.cpp
@ -1,12 +1,10 @@
 #include <time.h>
-#include <unistd.h>
+#include <port/unistd.h>
 #include <sys/types.h>
-
 #include <Common/Exception.h>
 #include <Common/randomSeed.h>
 #include <Common/SipHash.h>
 #include <Core/Types.h>
-
 #ifdef __APPLE__
 #include <common/apple_rt.h>
 #endif
--- a/dbms/src/Common/tests/compact_array.cpp
+++ b/dbms/src/Common/tests/compact_array.cpp
@ -7,15 +7,13 @@
 #include <Common/CompactArray.h>
 #include <IO/WriteBufferFromFile.h>
 #include <IO/ReadBufferFromFile.h>
-
 #include <boost/filesystem.hpp>
-
 #include <string>
 #include <iostream>
 #include <fstream>
 #include <stdexcept>
-#include <unistd.h>
 #include <cstdlib>
+#include <port/unistd.h>

 namespace fs = boost::filesystem;

--- a/dbms/src/Core/Block.cpp
+++ b/dbms/src/Core/Block.cpp
@ -312,7 +312,7 @@ MutableColumns Block::mutateColumns() const
    size_t num_columns = data.size();
    MutableColumns columns(num_columns);
    for (size_t i = 0; i < num_columns; ++i)
-        columns[i] = data[i].column ? data[i].column->mutate() : data[i].type->createColumn();
+        columns[i] = data[i].column ? (*std::move(data[i].column)).mutate() : data[i].type->createColumn();
    return columns;
 }

--- a/dbms/src/Core/Block.h
+++ b/dbms/src/Core/Block.h
@ -109,7 +109,7 @@ public:
    /** Get empty columns with the same types as in block. */
    MutableColumns cloneEmptyColumns() const;

-    /** Get columns from block for mutation. */
+    /** Get columns from block for mutation. Columns in block will be nullptr. */
    MutableColumns mutateColumns() const;

    /** Replace columns in a block */
--- a/dbms/src/Core/Defines.h
+++ b/dbms/src/Core/Defines.h
@ -60,6 +60,7 @@
 #define DBMS_MIN_REVISION_WITH_QUOTA_KEY_IN_CLIENT_INFO 54060
 #define DBMS_MIN_REVISION_WITH_TABLES_STATUS 54226
 #define DBMS_MIN_REVISION_WITH_TIME_ZONE_PARAMETER_IN_DATETIME_DATA_TYPE 54337
+#define DBMS_MIN_REVISION_WITH_SERVER_DISPLAY_NAME 54372

 /// Version of ClickHouse TCP protocol. Set to git tag with latest protocol change.
 #define DBMS_TCP_PROTOCOL_VERSION 54226
@ -74,8 +75,18 @@
 #define DEFAULT_HTTP_READ_BUFFER_TIMEOUT 1800
 #define DEFAULT_HTTP_READ_BUFFER_CONNECTION_TIMEOUT 1

-#define ALWAYS_INLINE __attribute__((__always_inline__))
-#define NO_INLINE __attribute__((__noinline__))
+// more aliases: https://mailman.videolan.org/pipermail/x264-devel/2014-May/010660.html
+
+#if defined(_MSC_VER)
+    #define ALWAYS_INLINE __forceinline
+    #define NO_INLINE static __declspec(noinline)
+    #define MAY_ALIAS
+#else
+    #define ALWAYS_INLINE __attribute__((__always_inline__))
+    #define NO_INLINE __attribute__((__noinline__))
+    #define MAY_ALIAS __attribute__((__may_alias__))
+#endif
+

 #define PLATFORM_NOT_SUPPORTED "The only supported platforms are x86_64 and AArch64 (work in progress)"

--- a/dbms/src/Core/Field.h
+++ b/dbms/src/Core/Field.h
@ -198,14 +198,14 @@ public:
    template <typename T> T & get()
    {
        using TWithoutRef = std::remove_reference_t<T>;
-        TWithoutRef * __attribute__((__may_alias__)) ptr = reinterpret_cast<TWithoutRef*>(&storage);
+        TWithoutRef * MAY_ALIAS ptr = reinterpret_cast<TWithoutRef*>(&storage);
        return *ptr;
    };

    template <typename T> const T & get() const
    {
        using TWithoutRef = std::remove_reference_t<T>;
-        const TWithoutRef * __attribute__((__may_alias__)) ptr = reinterpret_cast<const TWithoutRef*>(&storage);
+        const TWithoutRef * MAY_ALIAS ptr = reinterpret_cast<const TWithoutRef*>(&storage);
        return *ptr;
    };

@ -340,7 +340,7 @@ private:
    void createConcrete(T && x)
    {
        using JustT = std::decay_t<T>;
-        JustT * __attribute__((__may_alias__)) ptr = reinterpret_cast<JustT *>(&storage);
+        JustT * MAY_ALIAS ptr = reinterpret_cast<JustT *>(&storage);
        new (ptr) JustT(std::forward<T>(x));
        which = TypeToEnum<JustT>::value;
    }
@ -350,7 +350,7 @@ private:
    void assignConcrete(T && x)
    {
        using JustT = std::decay_t<T>;
-        JustT * __attribute__((__may_alias__)) ptr = reinterpret_cast<JustT *>(&storage);
+        JustT * MAY_ALIAS ptr = reinterpret_cast<JustT *>(&storage);
        *ptr = std::forward<T>(x);
    }

@ -398,7 +398,7 @@ private:

    void create(const char * data, size_t size)
    {
-        String * __attribute__((__may_alias__)) ptr = reinterpret_cast<String*>(&storage);
+        String * MAY_ALIAS ptr = reinterpret_cast<String*>(&storage);
        new (ptr) String(data, size);
        which = Types::String;
    }
@ -434,7 +434,7 @@ private:
    template <typename T>
    void destroy()
    {
-        T * __attribute__((__may_alias__)) ptr = reinterpret_cast<T*>(&storage);
+        T * MAY_ALIAS ptr = reinterpret_cast<T*>(&storage);
        ptr->~T();
    }
 };
--- a/dbms/src/Core/NamesAndTypes.cpp
+++ b/dbms/src/Core/NamesAndTypes.cpp
@ -138,4 +138,14 @@ NamesAndTypesList NamesAndTypesList::addTypes(const Names & names) const
    return res;
 }

+bool NamesAndTypesList::contains(const String & name) const
+{
+    for (const NameAndTypePair & column : *this)
+    {
+        if (column.name == name)
+            return true;
+    }
+    return false;
+}
+
 }
--- a/dbms/src/Core/NamesAndTypes.h
+++ b/dbms/src/Core/NamesAndTypes.h
@ -69,6 +69,8 @@ public:

    /// Unlike `filter`, returns columns in the order in which they go in `names`.
    NamesAndTypesList addTypes(const Names & names) const;
+
+    bool contains(const String & name) const;
 };

 }
--- a/dbms/src/Core/Protocol.h
+++ b/dbms/src/Core/Protocol.h
@ -116,7 +116,7 @@ namespace Protocol
    };

    /// Whether the ssl must be used.
-    enum class Encryption
+    enum class Secure
    {
        Disable = 0,
        Enable = 1,
--- a/dbms/src/Core/iostream_debug_helpers.cpp
+++ b/dbms/src/Core/iostream_debug_helpers.cpp
@ -44,7 +44,7 @@ std::ostream & operator<<(std::ostream & stream, const IDataType & what)
 std::ostream & operator<<(std::ostream & stream, const IStorage & what)
 {
    stream << "IStorage(name = " << what.getName() << ", tableName = " << what.getTableName() << ") {"
-           << what.getColumnsList().toString()
+           << what.getColumns().getAllPhysical().toString()
           << "}";
    // isRemote supportsSampling supportsFinal supportsPrewhere
    return stream;
--- a/dbms/src/DataStreams/ColumnGathererStream.cpp
+++ b/dbms/src/DataStreams/ColumnGathererStream.cpp
@ -76,7 +76,7 @@ Block ColumnGathererStream::readImpl()
        return Block();

    output_block = Block{column.cloneEmpty()};
-    MutableColumnPtr output_column = output_block.getByPosition(0).column->mutate();
+    MutableColumnPtr output_column = output_block.getByPosition(0).column->assumeMutable();
    output_column->gather(*this);
    if (!output_column->empty())
        output_block.getByPosition(0).column = std::move(output_column);
--- a/dbms/src/DataStreams/MergingSortedBlockInputStream.cpp
+++ b/dbms/src/DataStreams/MergingSortedBlockInputStream.cpp
@ -221,7 +221,7 @@ void MergingSortedBlockInputStream::merge(MutableColumns & merged_columns, std::
                    throw Exception("Logical error in MergingSortedBlockInputStream", ErrorCodes::LOGICAL_ERROR);

                for (size_t i = 0; i < num_columns; ++i)
-                    merged_columns[i] = source_blocks[source_num]->getByPosition(i).column->mutate();
+                    merged_columns[i] = (*std::move(source_blocks[source_num]->getByPosition(i).column)).mutate();

    //            std::cerr << "copied columns\n";

@ -233,7 +233,7 @@ void MergingSortedBlockInputStream::merge(MutableColumns & merged_columns, std::
                    for (size_t i = 0; i < num_columns; ++i)
                    {
                        auto & column = merged_columns[i];
-                        column = column->cut(0, merged_rows);
+                        column = (*column->cut(0, merged_rows)).mutate();
                    }

                    cancel(false);
--- a/dbms/src/DataStreams/PrettyBlockOutputStream.cpp
+++ b/dbms/src/DataStreams/PrettyBlockOutputStream.cpp
@ -1,6 +1,5 @@
 #include <sys/ioctl.h>
-#include <unistd.h>
-
+#include <port/unistd.h>
 #include <DataStreams/PrettyBlockOutputStream.h>
 #include <IO/WriteBuffer.h>
 #include <IO/WriteHelpers.h>
--- a/dbms/src/DataStreams/PushingToViewsBlockOutputStream.cpp
+++ b/dbms/src/DataStreams/PushingToViewsBlockOutputStream.cpp
@ -1,4 +1,5 @@
 #include <DataStreams/PushingToViewsBlockOutputStream.h>
+#include <DataStreams/SquashingBlockInputStream.h>
 #include <Interpreters/InterpreterSelectQuery.h>
 #include <Storages/MergeTree/ReplicatedMergeTreeBlockOutputStream.h>

@ -35,7 +36,7 @@ PushingToViewsBlockOutputStream::PushingToViewsBlockOutputStream(
            auto & materialized_view = dynamic_cast<const StorageMaterializedView &>(*dependent_table);

            auto query = materialized_view.getInnerQuery();
-            auto out = std::make_shared<PushingToViewsBlockOutputStream>(
+            BlockOutputStreamPtr out = std::make_shared<PushingToViewsBlockOutputStream>(
                database_table.first, database_table.second, dependent_table, *views_context, ASTPtr());
            views.emplace_back(ViewInfo{std::move(query), database_table.first, database_table.second, std::move(out)});
        }
@ -66,8 +67,19 @@ void PushingToViewsBlockOutputStream::write(const Block & block)
        {
            BlockInputStreamPtr from = std::make_shared<OneBlockInputStream>(block);
            InterpreterSelectQuery select(view.query, *views_context, {}, QueryProcessingStage::Complete, 0, from);
-            BlockInputStreamPtr data = std::make_shared<MaterializingBlockInputStream>(select.execute().in);
-            copyData(*data, *view.out);
+            BlockInputStreamPtr in = std::make_shared<MaterializingBlockInputStream>(select.execute().in);
+            /// Squashing is needed here because the materialized view query can generate a lot of blocks
+            /// even when only one block is inserted into the parent table (e.g. if the query is a GROUP BY
+            /// and two-level aggregation is triggered).
+            in = std::make_shared<SquashingBlockInputStream>(
+                in, context.getSettingsRef().min_insert_block_size_rows, context.getSettingsRef().min_insert_block_size_bytes);
+
+            in->readPrefix();
+
+            while (Block result_block = in->read())
+                view.out->write(result_block);
+
+            in->readSuffix();
        }
        catch (Exception & ex)
        {
--- a/dbms/src/DataStreams/PushingToViewsBlockOutputStream.h
+++ b/dbms/src/DataStreams/PushingToViewsBlockOutputStream.h
@ -29,18 +29,27 @@ public:
    {
        if (output)
            output->flush();
+
+        for (auto & view : views)
+            view.out->flush();
    }

    void writePrefix() override
    {
        if (output)
            output->writePrefix();
+
+        for (auto & view : views)
+            view.out->writePrefix();
    }

    void writeSuffix() override
    {
        if (output)
            output->writeSuffix();
+
+        for (auto & view : views)
+            view.out->writeSuffix();
    }

 private:
--- a/dbms/src/DataStreams/RemoteBlockInputStream.cpp
+++ b/dbms/src/DataStreams/RemoteBlockInputStream.cpp
@ -138,7 +138,7 @@ void RemoteBlockInputStream::sendExternalTables()
            {
                StoragePtr cur = table.second;
                QueryProcessingStage::Enum stage = QueryProcessingStage::Complete;
-                BlockInputStreams input = cur->read(cur->getColumnNamesList(), {}, context,
+                BlockInputStreams input = cur->read(cur->getColumns().getNamesOfPhysical(), {}, context,
                    stage, DEFAULT_BLOCK_SIZE, 1);
                if (input.size() == 0)
                    res.push_back(std::make_pair(std::make_shared<OneBlockInputStream>(cur->getSampleBlock()), table.first));
--- a/dbms/src/DataStreams/SquashingTransform.cpp
+++ b/dbms/src/DataStreams/SquashingTransform.cpp
@ -62,7 +62,7 @@ void SquashingTransform::append(Block && block)

    for (size_t i = 0; i < columns; ++i)
    {
-        MutableColumnPtr mutable_column = accumulated_block.getByPosition(i).column->mutate();
+        MutableColumnPtr mutable_column = (*std::move(accumulated_block.getByPosition(i).column)).mutate();
        mutable_column->insertRangeFrom(*block.getByPosition(i).column, 0, rows);
        accumulated_block.getByPosition(i).column = std::move(mutable_column);
    }
--- a/dbms/src/DataStreams/SummingSortedBlockInputStream.cpp
+++ b/dbms/src/DataStreams/SummingSortedBlockInputStream.cpp
@ -259,11 +259,11 @@ Block SummingSortedBlockInputStream::readImpl()
        if (checkDataType<DataTypeTuple>(desc.function->getReturnType().get()))
        {
            size_t tuple_size = desc.column_numbers.size();
-            Columns tuple_columns(tuple_size);
+            MutableColumns tuple_columns(tuple_size);
            for (size_t i = 0; i < tuple_size; ++i)
-                tuple_columns[i] = header.safeGetByPosition(desc.column_numbers[i]).column;
+                tuple_columns[i] = header.safeGetByPosition(desc.column_numbers[i]).column->assumeMutable();

-            desc.merged_column = ColumnTuple::create(tuple_columns);
+            desc.merged_column = ColumnTuple::create(std::move(tuple_columns));
        }
        else
            desc.merged_column = header.safeGetByPosition(desc.column_numbers[0]).column->cloneEmpty();
--- a/dbms/src/DataStreams/tests/filter_stream_hitlog.cpp
+++ b/dbms/src/DataStreams/tests/filter_stream_hitlog.cpp
@ -104,8 +104,8 @@ int main(int, char **)

        /// create an object of an existing hit log table

-        StoragePtr table = StorageLog::create("./", "HitLog", names_and_types_list,
-            NamesAndTypesList{}, NamesAndTypesList{}, ColumnDefaults{}, DEFAULT_MAX_COMPRESS_BLOCK_SIZE);
+        StoragePtr table = StorageLog::create(
+            "./", "HitLog", ColumnsDescription{names_and_types_list}, DEFAULT_MAX_COMPRESS_BLOCK_SIZE);
        table->startup();

        /// read from it, apply the expression, filter, and write in tsv form to the console
--- a/dbms/src/DataStreams/tests/native_streams.cpp
+++ b/dbms/src/DataStreams/tests/native_streams.cpp
@ -95,8 +95,8 @@ try

    /// create an object of an existing hit log table

-    StoragePtr table = StorageLog::create("./", "HitLog", names_and_types_list,
-        NamesAndTypesList{}, NamesAndTypesList{}, ColumnDefaults{}, DEFAULT_MAX_COMPRESS_BLOCK_SIZE);
+    StoragePtr table = StorageLog::create(
+        "./", "HitLog", ColumnsDescription{names_and_types_list}, DEFAULT_MAX_COMPRESS_BLOCK_SIZE);
    table->startup();

    /// read from it
--- a/dbms/src/DataStreams/tests/sorting_stream.cpp
+++ b/dbms/src/DataStreams/tests/sorting_stream.cpp
@ -107,8 +107,8 @@ try

    /// create an object of an existing hit log table

-    StoragePtr table = StorageLog::create("./", "HitLog", names_and_types_list,
-        NamesAndTypesList{}, NamesAndTypesList{}, ColumnDefaults{}, DEFAULT_MAX_COMPRESS_BLOCK_SIZE);
+    StoragePtr table = StorageLog::create(
+        "./", "HitLog", ColumnsDescription{names_and_types_list}, DEFAULT_MAX_COMPRESS_BLOCK_SIZE);
    table->startup();

    /// read from it, sort it, and write it in tsv form to the console
--- a/dbms/src/DataTypes/DataTypeTuple.cpp
+++ b/dbms/src/DataTypes/DataTypeTuple.cpp
@ -329,10 +329,10 @@ void DataTypeTuple::deserializeBinaryBulkWithMultipleStreams(
 MutableColumnPtr DataTypeTuple::createColumn() const
 {
    size_t size = elems.size();
-    Columns tuple_columns(size);
+    MutableColumns tuple_columns(size);
    for (size_t i = 0; i < size; ++i)
        tuple_columns[i] = elems[i]->createColumn();
-    return ColumnTuple::create(tuple_columns);
+    return ColumnTuple::create(std::move(tuple_columns));
 }

 Field DataTypeTuple::getDefault() const
--- a/dbms/src/Databases/DatabaseDictionary.cpp
+++ b/dbms/src/Databases/DatabaseDictionary.cpp
@ -3,15 +3,21 @@
 #include <Interpreters/ExternalDictionaries.h>
 #include <Storages/StorageDictionary.h>
 #include <common/logger_useful.h>
+#include <Parsers/IAST.h>
+#include <IO/WriteBufferFromString.h>
+#include <IO/Operators.h>
+#include <Parsers/ParserCreateQuery.h>
+#include <Parsers/parseQuery.h>

 namespace DB
 {
 namespace ErrorCodes
 {
-extern const int TABLE_ALREADY_EXISTS;
-extern const int UNKNOWN_TABLE;
-extern const int LOGICAL_ERROR;
-extern const int CANNOT_GET_CREATE_TABLE_QUERY;
+    extern const int TABLE_ALREADY_EXISTS;
+    extern const int UNKNOWN_TABLE;
+    extern const int LOGICAL_ERROR;
+    extern const int CANNOT_GET_CREATE_TABLE_QUERY;
+    extern const int SYNTAX_ERROR;
 }

 DatabaseDictionary::DatabaseDictionary(const String & name_, const Context & context)
@ -41,8 +47,7 @@ Tables DatabaseDictionary::loadTables()
        {
            const DictionaryStructure & dictionary_structure = dict_ptr->getStructure();
            auto columns = StorageDictionary::getNamesAndTypes(dictionary_structure);
-            tables[name] = StorageDictionary::create(name,
-                columns, NamesAndTypesList{}, NamesAndTypesList{}, ColumnDefaults{}, dictionary_structure, name);
+            tables[name] = StorageDictionary::create(name, ColumnsDescription{columns}, dictionary_structure, name);
        }
    }

@ -76,8 +81,7 @@ StoragePtr DatabaseDictionary::tryGetTable(
            {
                const DictionaryStructure & dictionary_structure = dict_ptr->getStructure();
                auto columns = StorageDictionary::getNamesAndTypes(dictionary_structure);
-                return StorageDictionary::create(table_name,
-                    columns, NamesAndTypesList{}, NamesAndTypesList{}, ColumnDefaults{}, dictionary_structure, table_name);
+                return StorageDictionary::create(table_name, ColumnsDescription{columns}, dictionary_structure, table_name);
            }
        }
    }
@ -87,7 +91,7 @@ StoragePtr DatabaseDictionary::tryGetTable(

 DatabaseIteratorPtr DatabaseDictionary::getIterator(const Context & /*context*/)
 {
-    return std::make_unique<DatabaseSnaphotIterator>(loadTables());
+    return std::make_unique<DatabaseSnapshotIterator>(loadTables());
 }

 bool DatabaseDictionary::empty(const Context & /*context*/) const
@ -142,10 +146,7 @@ void DatabaseDictionary::renameTable(
 void DatabaseDictionary::alterTable(
    const Context &,
    const String &,
-    const NamesAndTypesList &,
-    const NamesAndTypesList &,
-    const NamesAndTypesList &,
-    const ColumnDefaults &,
+    const ColumnsDescription &,
    const ASTModifier &)
 {
    throw Exception("DatabaseDictionary: alterTable() is not supported", ErrorCodes::NOT_IMPLEMENTED);
@ -158,11 +159,54 @@ time_t DatabaseDictionary::getTableMetadataModificationTime(
    return static_cast<time_t>(0);
 }

-ASTPtr DatabaseDictionary::getCreateQuery(
-    const Context &,
-    const String &) const
+ASTPtr DatabaseDictionary::getCreateTableQueryImpl(const Context & context,
+                                                   const String & table_name, bool throw_on_error) const
 {
-    throw Exception("There is no CREATE TABLE query for DatabaseDictionary tables", ErrorCodes::CANNOT_GET_CREATE_TABLE_QUERY);
+    String query;
+    {
+        WriteBufferFromString buffer(query);
+
+        const auto & dictionaries = context.getExternalDictionaries();
+        auto dictionary = throw_on_error ? dictionaries.getDictionary(table_name)
+                                         : dictionaries.tryGetDictionary(table_name);
+
+        auto names_and_types = StorageDictionary::getNamesAndTypes(dictionary->getStructure());
+        buffer << "CREATE TABLE " << backQuoteIfNeed(name) << '.' << backQuoteIfNeed(table_name) << " (";
+        buffer << StorageDictionary::generateNamesAndTypesDescription(names_and_types.begin(), names_and_types.end());
+        buffer << ") Engine = Dictionary(" << backQuoteIfNeed(table_name) << ")";
+    }
+
+    ParserCreateQuery parser;
+    const char * pos = query.data();
+    std::string error_message;
+    auto ast = tryParseQuery(parser, pos, pos + query.size(), error_message,
+            /* hilite = */ false, "", /* allow_multi_statements = */ false);
+
+    if (!ast && throw_on_error)
+        throw Exception(error_message, ErrorCodes::SYNTAX_ERROR);
+
+    return ast;
+}
+
+ASTPtr DatabaseDictionary::getCreateTableQuery(const Context & context, const String & table_name) const
+{
+    return getCreateTableQueryImpl(context, table_name, true);
+}
+
+ASTPtr DatabaseDictionary::tryGetCreateTableQuery(const Context & context, const String & table_name) const
+{
+    return getCreateTableQueryImpl(context, table_name, false);
+}
+
+ASTPtr DatabaseDictionary::getCreateDatabaseQuery(const Context & /*context*/) const
+{
+    String query;
+    {
+        WriteBufferFromString buffer(query);
+        buffer << "CREATE DATABASE " << backQuoteIfNeed(name) << " ENGINE = Dictionary";
+    }
+    ParserCreateQuery parser;
+    return parseQuery(parser, query.data(), query.data() + query.size(), "");
 }

 void DatabaseDictionary::shutdown()
--- a/dbms/src/Databases/DatabaseDictionary.h
+++ b/dbms/src/Databases/DatabaseDictionary.h
@ -22,16 +22,6 @@ class ExternalDictionaries;
 */
 class DatabaseDictionary : public IDatabase
 {
-private:
-    const String name;
-    mutable std::mutex mutex;
-    const ExternalDictionaries & external_dictionaries;
-    std::unordered_set<String> deleted_tables;
-
-    Poco::Logger * log;
-
-    Tables loadTables();
-
 public:
    DatabaseDictionary(const String & name_, const Context & context);

@ -79,22 +69,37 @@ public:
    void alterTable(
        const Context & context,
        const String & name,
-        const NamesAndTypesList & columns,
-        const NamesAndTypesList & materialized_columns,
-        const NamesAndTypesList & alias_columns,
-        const ColumnDefaults & column_defaults,
+        const ColumnsDescription & columns,
        const ASTModifier & engine_modifier) override;

    time_t getTableMetadataModificationTime(
        const Context & context,
        const String & table_name) override;

-    ASTPtr getCreateQuery(
+    ASTPtr getCreateTableQuery(
        const Context & context,
        const String & table_name) const override;

+    ASTPtr tryGetCreateTableQuery(
+            const Context & context,
+            const String & table_name) const override;
+
+    ASTPtr getCreateDatabaseQuery(const Context & context) const override;
+
    void shutdown() override;
    void drop() override;
+
+private:
+    const String name;
+    mutable std::mutex mutex;
+    const ExternalDictionaries & external_dictionaries;
+    std::unordered_set<String> deleted_tables;
+
+    Poco::Logger * log;
+
+    Tables loadTables();
+
+    ASTPtr getCreateTableQueryImpl(const Context & context, const String & table_name, bool throw_on_error) const;
 };

 }
--- a/dbms/src/Databases/DatabaseMemory.cpp
+++ b/dbms/src/Databases/DatabaseMemory.cpp
@ -8,75 +8,22 @@ namespace DB

 namespace ErrorCodes
 {
-    extern const int TABLE_ALREADY_EXISTS;
-    extern const int UNKNOWN_TABLE;
-    extern const int LOGICAL_ERROR;
    extern const int CANNOT_GET_CREATE_TABLE_QUERY;
 }

+DatabaseMemory::DatabaseMemory(String name_)
+    : DatabaseWithOwnTablesBase(std::move(name_))
+    , log(&Logger::get("DatabaseMemory(" + name + ")"))
+{}
+
 void DatabaseMemory::loadTables(
    Context & /*context*/,
    ThreadPool * /*thread_pool*/,
    bool /*has_force_restore_data_flag*/)
 {
-    log = &Logger::get("DatabaseMemory(" + name + ")");
-
    /// Nothing to load.
 }

-bool DatabaseMemory::isTableExist(
-    const Context & /*context*/,
-    const String & table_name) const
-{
-    std::lock_guard<std::mutex> lock(mutex);
-    return tables.find(table_name) != tables.end();
-}
-
-StoragePtr DatabaseMemory::tryGetTable(
-    const Context & /*context*/,
-    const String & table_name) const
-{
-    std::lock_guard<std::mutex> lock(mutex);
-    auto it = tables.find(table_name);
-    if (it == tables.end())
-        return {};
-    return it->second;
-}
-
-DatabaseIteratorPtr DatabaseMemory::getIterator(const Context & /*context*/)
-{
-    std::lock_guard<std::mutex> lock(mutex);
-    return std::make_unique<DatabaseSnaphotIterator>(tables);
-}
-
-bool DatabaseMemory::empty(const Context & /*context*/) const
-{
-    std::lock_guard<std::mutex> lock(mutex);
-    return tables.empty();
-}
-
-StoragePtr DatabaseMemory::detachTable(const String & table_name)
-{
-    StoragePtr res;
-    {
-        std::lock_guard<std::mutex> lock(mutex);
-        auto it = tables.find(table_name);
-        if (it == tables.end())
-            throw Exception("Table " + name + "." + table_name + " doesn't exist.", ErrorCodes::UNKNOWN_TABLE);
-        res = it->second;
-        tables.erase(it);
-    }
-
-    return res;
-}
-
-void DatabaseMemory::attachTable(const String & table_name, const StoragePtr & table)
-{
-    std::lock_guard<std::mutex> lock(mutex);
-    if (!tables.emplace(table_name, table).second)
-        throw Exception("Table " + name + "." + table_name + " already exists.", ErrorCodes::TABLE_ALREADY_EXISTS);
-}
-
 void DatabaseMemory::createTable(
    const Context & /*context*/,
    const String & table_name,
@ -105,10 +52,7 @@ void DatabaseMemory::renameTable(
 void DatabaseMemory::alterTable(
    const Context &,
    const String &,
-    const NamesAndTypesList &,
-    const NamesAndTypesList &,
-    const NamesAndTypesList &,
-    const ColumnDefaults &,
+    const ColumnsDescription &,
    const ASTModifier &)
 {
    throw Exception("DatabaseMemory: alterTable() is not supported", ErrorCodes::NOT_IMPLEMENTED);
@ -121,31 +65,17 @@ time_t DatabaseMemory::getTableMetadataModificationTime(
    return static_cast<time_t>(0);
 }

-ASTPtr DatabaseMemory::getCreateQuery(
+ASTPtr DatabaseMemory::getCreateTableQuery(
    const Context &,
    const String &) const
 {
    throw Exception("There is no CREATE TABLE query for DatabaseMemory tables", ErrorCodes::CANNOT_GET_CREATE_TABLE_QUERY);
 }

-void DatabaseMemory::shutdown()
+ASTPtr DatabaseMemory::getCreateDatabaseQuery(
+    const Context &) const
 {
-    /// You can not hold a lock during shutdown.
-    /// Because inside `shutdown` function tables can work with database, and mutex is not recursive.
-
-    Tables tables_snapshot;
-    {
-        std::lock_guard<std::mutex> lock(mutex);
-        tables_snapshot = tables;
-    }
-
-    for (const auto & kv: tables_snapshot)
-    {
-        kv.second->shutdown();
-    }
-
-    std::lock_guard<std::mutex> lock(mutex);
-    tables.clear();
+    throw Exception("There is no CREATE DATABASE query for DatabaseMemory", ErrorCodes::CANNOT_GET_CREATE_TABLE_QUERY);
 }

 void DatabaseMemory::drop()
--- a/dbms/src/Databases/DatabaseMemory.h
+++ b/dbms/src/Databases/DatabaseMemory.h
@ -1,8 +1,6 @@
 #pragma once

-#include <mutex>
-#include <Databases/IDatabase.h>
-#include <Storages/IStorage.h>
+#include <Databases/DatabasesCommon.h>


 namespace Poco { class Logger; }
@ -16,18 +14,10 @@ namespace DB
  * All tables are created by calling code.
  * TODO: Maybe DatabaseRuntime is more suitable class name.
  */
-class DatabaseMemory : public IDatabase
+class DatabaseMemory : public DatabaseWithOwnTablesBase
 {
-protected:
-    const String name;
-    mutable std::mutex mutex;
-    Tables tables;
-
-    Poco::Logger * log;
-
 public:
-
-    DatabaseMemory(const String & name_) : name(name_) {}
+    DatabaseMemory(String name_);

    String getEngineName() const override { return "Memory"; }

@ -36,18 +26,6 @@ public:
        ThreadPool * thread_pool,
        bool has_force_restore_data_flag) override;

-    bool empty(const Context & context) const override;
-
-    DatabaseIteratorPtr getIterator(const Context & context) override;
-
-    bool isTableExist(
-        const Context & context,
-        const String & table_name) const override;
-
-    StoragePtr tryGetTable(
-        const Context & context,
-        const String & table_name) const override;
-
    void createTable(
        const Context & context,
        const String & table_name,
@ -58,9 +36,6 @@ public:
        const Context & context,
        const String & table_name) override;

-    void attachTable(const String & table_name, const StoragePtr & table) override;
-    StoragePtr detachTable(const String & table_name) override;
-
    void renameTable(
        const Context & context,
        const String & table_name,
@ -70,22 +45,22 @@ public:
    void alterTable(
        const Context & context,
        const String & name,
-        const NamesAndTypesList & columns,
-        const NamesAndTypesList & materialized_columns,
-        const NamesAndTypesList & alias_columns,
-        const ColumnDefaults & column_defaults,
+        const ColumnsDescription & columns,
        const ASTModifier & engine_modifier) override;

    time_t getTableMetadataModificationTime(
        const Context & context,
        const String & table_name) override;

-    ASTPtr getCreateQuery(
-        const Context & context,
-        const String & table_name) const override;
+    ASTPtr getCreateTableQuery(const Context & context, const String & table_name) const override;
+    ASTPtr tryGetCreateTableQuery(const Context &, const String &) const override { return nullptr; }
+
+    ASTPtr getCreateDatabaseQuery(const Context & context) const override;

-    void shutdown() override;
    void drop() override;
+
+private:
+    Poco::Logger * log;
 };

 }
--- a/Show More
+++ b/Show More