Merge remote-tracking branch 'upstream/master' into replxx

2024-09-25 03:00:49 +00:00 · 2020-01-20 15:52:45 +03:00 · 2020-01-20 15:52:45 +03:00 · 03fdadee04
commit 03fdadee04
parent 2fc9f56fe2 1e72b37a21
37 changed files with 543 additions and 210 deletions
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -352,6 +352,7 @@ include (cmake/find/simdjson.cmake)
 include (cmake/find/rapidjson.cmake)
 include (cmake/find/fastops.cmake)
 include (cmake/find/orc.cmake)
+include (cmake/find/replxx.cmake)

 find_contrib_lib(cityhash)
 find_contrib_lib(farmhash)
--- a/cmake/find/replxx.cmake
+++ b/cmake/find/replxx.cmake
@ -0,0 +1,40 @@
+option (ENABLE_REPLXX "Enable replxx support" ${NOT_UNBUNDLED})
+
+if (ENABLE_REPLXX)
+    option (USE_INTERNAL_REPLXX "Use internal replxx library" ${NOT_UNBUNDLED})
+
+    if (USE_INTERNAL_REPLXX AND NOT EXISTS "${ClickHouse_SOURCE_DIR}/contrib/replxx/README.md")
+       message (WARNING "submodule contrib/replxx is missing. to fix try run: \n git submodule update --init --recursive")
+       set (USE_INTERNAL_REPLXX 0)
+    endif ()
+
+    if (NOT USE_INTERNAL_REPLXX)
+        find_library(LIBRARY_REPLXX NAMES replxx replxx-static)
+        find_path(INCLUDE_REPLXX replxx.hxx)
+
+        add_library(replxx UNKNOWN IMPORTED)
+        set_property(TARGET replxx PROPERTY IMPORTED_LOCATION ${LIBRARY_REPLXX})
+        target_include_directories(replxx PUBLIC ${INCLUDE_REPLXX})
+
+        set(CMAKE_REQUIRED_LIBRARIES replxx)
+        check_cxx_source_compiles(
+            "
+            #include <replxx.hxx>
+            int main() {
+                replxx::Replxx rx;
+            }
+            "
+            EXTERNAL_REPLXX_WORKS
+        )
+
+        if (NOT EXTERNAL_REPLXX_WORKS)
+            message (FATAL_ERROR "replxx is unusable: ${LIBRARY_REPLXX} ${INCLUDE_REPLXX}")
+        endif ()
+    endif ()
+
+    set(USE_REPLXX 1)
+
+    message (STATUS "Using replxx")
+else ()
+    set(USE_REPLXX 0)
+endif ()
--- a/contrib/CMakeLists.txt
+++ b/contrib/CMakeLists.txt
@ -332,4 +332,6 @@ if (USE_FASTOPS)
    add_subdirectory (fastops-cmake)
 endif()

-add_subdirectory (replxx-cmake)
+if (USE_INTERNAL_REPLXX)
+    add_subdirectory (replxx-cmake)
+endif()
--- a/contrib/replxx-cmake/CMakeLists.txt
+++ b/contrib/replxx-cmake/CMakeLists.txt
@ -1,53 +1,18 @@
-option (ENABLE_READLINE "Enable readline support" ${ENABLE_LIBRARIES})
+set (LIBRARY_DIR "${ClickHouse_SOURCE_DIR}/contrib/replxx")

-if (ENABLE_READLINE)
-    option (USE_INTERNAL_REPLXX "Use internal replxx library" ${NOT_UNBUNDLED})
+set(SRCS
+    ${LIBRARY_DIR}/src/conversion.cxx
+    ${LIBRARY_DIR}/src/escape.cxx
+    ${LIBRARY_DIR}/src/history.cxx
+    ${LIBRARY_DIR}/src/io.cxx
+    ${LIBRARY_DIR}/src/prompt.cxx
+    ${LIBRARY_DIR}/src/replxx.cxx
+    ${LIBRARY_DIR}/src/replxx_impl.cxx
+    ${LIBRARY_DIR}/src/util.cxx
+    ${LIBRARY_DIR}/src/wcwidth.cpp
+    ${LIBRARY_DIR}/src/ConvertUTF.cpp
+)

-    if (USE_INTERNAL_REPLXX)
-        set (LIBRARY_DIR "${ClickHouse_SOURCE_DIR}/contrib/replxx")
-
-        set(SRCS
-            ${LIBRARY_DIR}/src/conversion.cxx
-            ${LIBRARY_DIR}/src/ConvertUTF.cpp
-            ${LIBRARY_DIR}/src/escape.cxx
-            ${LIBRARY_DIR}/src/history.cxx
-            ${LIBRARY_DIR}/src/io.cxx
-            ${LIBRARY_DIR}/src/prompt.cxx
-            ${LIBRARY_DIR}/src/replxx.cxx
-            ${LIBRARY_DIR}/src/replxx_impl.cxx
-            ${LIBRARY_DIR}/src/util.cxx
-            ${LIBRARY_DIR}/src/wcwidth.cpp
-            ${LIBRARY_DIR}/src/windows.cxx
-        )
-
-        add_library(replxx ${SRCS})
-        target_include_directories(replxx PUBLIC ${LIBRARY_DIR}/include)
-        target_compile_options(replxx PUBLIC -Wno-documentation)
-    else ()
-        find_library(LIBRARY_REPLXX NAMES replxx replxx-static)
-        find_path(INCLUDE_REPLXX replxx.hxx)
-
-        add_library(replxx UNKNOWN IMPORTED)
-        set_property(TARGET replxx PROPERTY IMPORTED_LOCATION ${LIBRARY_REPLXX})
-        target_include_directories(replxx PUBLIC ${INCLUDE_REPLXX})
-
-        set(CMAKE_REQUIRED_LIBRARIES replxx)
-        check_cxx_source_compiles(
-            "
-            #include <replxx.hxx>
-            int main() {
-                replxx::Replxx rx;
-            }
-            "
-            EXTERNAL_REPLXX_WORKS
-        )
-
-        if (NOT EXTERNAL_REPLXX_WORKS)
-            message (FATAL_ERROR "replxx is unusable: ${LIBRARY_REPLXX} ${INCLUDE_REPLXX}")
-        endif ()
-    endif ()
-
-    target_compile_definitions(replxx PUBLIC USE_REPLXX)
-
-    message (STATUS "Using replxx")
-endif ()
+add_library(replxx ${SRCS})
+target_include_directories(replxx PUBLIC ${LIBRARY_DIR}/include)
+target_compile_options(replxx PUBLIC -Wno-documentation)
--- a/dbms/programs/client/Client.cpp
+++ b/dbms/programs/client/Client.cpp
@ -25,6 +25,7 @@
 #include <Poco/File.h>
 #include <Poco/Util/Application.h>
 #include <common/find_symbols.h>
+#include <common/LineReader.h>
 #include <Common/ClickHouseRevision.h>
 #include <Common/Stopwatch.h>
 #include <Common/Exception.h>
@ -483,7 +484,7 @@ private:

            if (server_revision >= Suggest::MIN_SERVER_REVISION && !config().getBool("disable_suggestion", false))
                /// Load suggestion data from the server.
-                Suggest::instance()->load(connection_parameters, config().getInt("suggestion_limit"));
+                Suggest::instance().load(connection_parameters, config().getInt("suggestion_limit"));

            /// Load command history if present.
            if (config().has("history_file"))
@ -551,17 +552,6 @@ private:
        }
        else
        {
-            /// This is intended for testing purposes.
-            if (config().getBool("always_load_suggestion_data", false))
-            {
-#ifdef USE_REPLXX
-                SCOPE_EXIT({ Suggest::instance().finalize(); });
-                Suggest::instance().load(connection_parameters, config().getInt("suggestion_limit"));
-#else
-                throw Exception("Command line suggestions cannot work without line editing library", ErrorCodes::BAD_ARGUMENTS);
-#endif
-            }
-
            query_id = config().getString("query_id", "");
            nonInteractive();

@ -1831,13 +1821,6 @@ public:
            server_logs_file = options["server_logs_file"].as<std::string>();
        if (options.count("disable_suggestion"))
            config().setBool("disable_suggestion", true);
-        if (options.count("always_load_suggestion_data"))
-        {
-            if (options.count("disable_suggestion"))
-                throw Exception("Command line parameters disable_suggestion (-A) and always_load_suggestion_data cannot be specified simultaneously",
-                    ErrorCodes::BAD_ARGUMENTS);
-            config().setBool("always_load_suggestion_data", true);
-        }
        if (options.count("suggestion_limit"))
            config().setInt("suggestion_limit", options["suggestion_limit"].as<int>());

--- a/dbms/programs/client/Suggest.h
+++ b/dbms/programs/client/Suggest.h
@ -18,10 +18,10 @@ namespace ErrorCodes
 class Suggest : public LineReader::Suggest, boost::noncopyable
 {
 public:
-    static Suggest * instance()
+    static Suggest & instance()
    {
        static Suggest instance;
-        return &instance;
+        return instance;
    }

    void load(const ConnectionParameters & connection_parameters, size_t suggestion_limit);
--- a/dbms/programs/server/MySQLHandler.cpp
+++ b/dbms/programs/server/MySQLHandler.cpp
@ -79,21 +79,19 @@ void MySQLHandler::run()
        if (!connection_context.mysql.max_packet_size)
            connection_context.mysql.max_packet_size = MAX_PACKET_LENGTH;

-/*        LOG_TRACE(log, "Capabilities: " << handshake_response.capability_flags
-                                        << "\nmax_packet_size: "
+        LOG_TRACE(log, "Capabilities: " << handshake_response.capability_flags
+                                        << ", max_packet_size: "
                                        << handshake_response.max_packet_size
-                                        << "\ncharacter_set: "
-                                        << handshake_response.character_set
-                                        << "\nuser: "
+                                        << ", character_set: "
+                                        << static_cast<int>(handshake_response.character_set)
+                                        << ", user: "
                                        << handshake_response.username
-                                        << "\nauth_response length: "
+                                        << ", auth_response length: "
                                        << handshake_response.auth_response.length()
-                                        << "\nauth_response: "
-                                        << handshake_response.auth_response
-                                        << "\ndatabase: "
+                                        << ", database: "
                                        << handshake_response.database
-                                        << "\nauth_plugin_name: "
-                                        << handshake_response.auth_plugin_name);*/
+                                        << ", auth_plugin_name: "
+                                        << handshake_response.auth_plugin_name);

        client_capability_flags = handshake_response.capability_flags;
        if (!(client_capability_flags & CLIENT_PROTOCOL_41))
--- a/dbms/programs/server/MySQLHandlerFactory.cpp
+++ b/dbms/programs/server/MySQLHandlerFactory.cpp
@ -34,7 +34,7 @@ MySQLHandlerFactory::MySQLHandlerFactory(IServer & server_)
    }
    catch (...)
    {
-        LOG_INFO(log, "Failed to create SSL context. SSL will be disabled. Error: " << getCurrentExceptionMessage(false));
+        LOG_TRACE(log, "Failed to create SSL context. SSL will be disabled. Error: " << getCurrentExceptionMessage(false));
        ssl_enabled = false;
    }
 #endif
@ -47,7 +47,7 @@ MySQLHandlerFactory::MySQLHandlerFactory(IServer & server_)
    }
    catch (...)
    {
-        LOG_WARNING(log, "Failed to read RSA keys. Error: " << getCurrentExceptionMessage(false));
+        LOG_TRACE(log, "Failed to read RSA key pair from server certificate. Error: " << getCurrentExceptionMessage(false));
        generateRSAKeys();
    }
 #endif
@ -104,7 +104,7 @@ void MySQLHandlerFactory::readRSAKeys()

 void MySQLHandlerFactory::generateRSAKeys()
 {
-    LOG_INFO(log, "Generating new RSA key.");
+    LOG_TRACE(log, "Generating new RSA key pair.");
    public_key.reset(RSA_new());
    if (!public_key)
        throw Exception("Failed to allocate RSA key. Error: " + getOpenSSLErrors(), ErrorCodes::OPENSSL_ERROR);
--- a/dbms/src/Core/MySQLProtocol.h
+++ b/dbms/src/Core/MySQLProtocol.h
@ -1030,6 +1030,7 @@ public:
            LOG_TRACE(log, "Authentication method match.");
        }

+        bool sent_public_key = false;
        if (auth_response == "\1")
        {
            LOG_TRACE(log, "Client requests public key.");
@ -1050,6 +1051,7 @@ public:

            AuthMoreData data(pem);
            packet_sender->sendPacket(data, true);
+            sent_public_key = true;

            AuthSwitchResponse response;
            packet_sender->receivePacket(response);
@ -1069,13 +1071,15 @@ public:
         */
        if (!is_secure_connection && !auth_response->empty() && auth_response != String("\0", 1))
        {
-            LOG_TRACE(log, "Received nonempty password");
+            LOG_TRACE(log, "Received nonempty password.");
            auto ciphertext = reinterpret_cast<unsigned char *>(auth_response->data());

            unsigned char plaintext[RSA_size(&private_key)];
            int plaintext_size = RSA_private_decrypt(auth_response->size(), ciphertext, plaintext, &private_key, RSA_PKCS1_OAEP_PADDING);
            if (plaintext_size == -1)
            {
+                if (!sent_public_key)
+                    LOG_WARNING(log, "Client could have encrypted password with different public key since it didn't request it from server.");
                throw Exception("Failed to decrypt auth data. Error: " + getOpenSSLErrors(), ErrorCodes::OPENSSL_ERROR);
            }

--- a/dbms/src/Functions/FunctionsLogical.cpp
+++ b/dbms/src/Functions/FunctionsLogical.cpp
@ -282,29 +282,32 @@ template <
    typename Op, template <typename, size_t> typename OperationApplierImpl, size_t N = 10>
 struct OperationApplier
 {
-    template <typename Columns, typename ResultColumn>
-    static void apply(Columns & in, ResultColumn & result)
+    template <typename Columns, typename ResultData>
+    static void apply(Columns & in, ResultData & result_data, bool use_result_data_as_input = false)
    {
-        while (in.size() > 1)
-        {
-            doBatchedApply(in, result->getData());
-            in.push_back(result.get());
-        }
+        if (!use_result_data_as_input)
+            doBatchedApply<false>(in, result_data);
+        while (in.size() > 0)
+            doBatchedApply<true>(in, result_data);
    }

-    template <typename Columns, typename ResultData>
+    template <bool CarryResult, typename Columns, typename ResultData>
    static void NO_INLINE doBatchedApply(Columns & in, ResultData & result_data)
    {
        if (N > in.size())
        {
-            OperationApplier<Op, OperationApplierImpl, N - 1>::doBatchedApply(in, result_data);
+            OperationApplier<Op, OperationApplierImpl, N - 1>
+                ::template doBatchedApply<CarryResult>(in, result_data);
            return;
        }

        const OperationApplierImpl<Op, N> operationApplierImpl(in);
        size_t i = 0;
        for (auto & res : result_data)
-            res = operationApplierImpl.apply(i++);
+            if constexpr (CarryResult)
+                res = Op::apply(res, operationApplierImpl.apply(i++));
+            else
+                res = operationApplierImpl.apply(i++);

        in.erase(in.end() - N, in.end());
    }
@ -312,9 +315,9 @@ struct OperationApplier

 template <
    typename Op, template <typename, size_t> typename OperationApplierImpl>
-struct OperationApplier<Op, OperationApplierImpl, 1>
+struct OperationApplier<Op, OperationApplierImpl, 0>
 {
-    template <typename Columns, typename Result>
+    template <bool, typename Columns, typename Result>
    static void NO_INLINE doBatchedApply(Columns &, Result &)
    {
        throw Exception(
@ -332,7 +335,7 @@ static void executeForTernaryLogicImpl(ColumnRawPtrs arguments, ColumnWithTypeAn
    const bool has_consts = extractConstColumnsTernary<Op>(arguments, const_3v_value);

    /// If the constant value uniquely determines the result, return it.
-    if (has_consts && (arguments.empty() || (Op::isSaturable() && Op::isSaturatedValue(const_3v_value))))
+    if (has_consts && (arguments.empty() || Op::isSaturatedValue(const_3v_value)))
    {
        result_info.column = ColumnConst::create(
            convertFromTernaryData(UInt8Container({const_3v_value}), result_info.type->isNullable()),
@ -341,16 +344,10 @@ static void executeForTernaryLogicImpl(ColumnRawPtrs arguments, ColumnWithTypeAn
        return;
    }

-    const auto result_column = ColumnUInt8::create(input_rows_count);
-    MutableColumnPtr const_column_holder;
-    if (has_consts)
-    {
-        const_column_holder =
-                convertFromTernaryData(UInt8Container(input_rows_count, const_3v_value), const_3v_value == Ternary::Null);
-        arguments.push_back(const_column_holder.get());
-    }
+    const auto result_column = has_consts ?
+            ColumnUInt8::create(input_rows_count, const_3v_value) : ColumnUInt8::create(input_rows_count);

-    OperationApplier<Op, AssociativeGenericApplierImpl>::apply(arguments, result_column);
+    OperationApplier<Op, AssociativeGenericApplierImpl>::apply(arguments, result_column->getData(), has_consts);

    result_info.column = convertFromTernaryData(result_column->getData(), result_info.type->isNullable());
 }
@ -425,19 +422,8 @@ static void basicExecuteImpl(ColumnRawPtrs arguments, ColumnWithTypeAndName & re
    if (has_consts && Op::apply(const_val, 0) == 0 && Op::apply(const_val, 1) == 1)
        has_consts = false;

-    UInt8ColumnPtrs uint8_args;
-
-    auto col_res = ColumnUInt8::create();
-    UInt8Container & vec_res = col_res->getData();
-    if (has_consts)
-    {
-        vec_res.assign(input_rows_count, const_val);
-        uint8_args.push_back(col_res.get());
-    }
-    else
-    {
-        vec_res.resize(input_rows_count);
-    }
+    auto col_res = has_consts ?
+            ColumnUInt8::create(input_rows_count, const_val) : ColumnUInt8::create(input_rows_count);

    /// FastPath detection goes in here
    if (arguments.size() == (has_consts ? 1 : 2))
@ -452,7 +438,8 @@ static void basicExecuteImpl(ColumnRawPtrs arguments, ColumnWithTypeAndName & re
    }

    /// Convert all columns to UInt8
-    Columns converted_columns;
+    UInt8ColumnPtrs uint8_args;
+    Columns converted_columns_holder;
    for (const IColumn * column : arguments)
    {
        if (auto uint8_column = checkAndGetColumn<ColumnUInt8>(column))
@ -462,15 +449,11 @@ static void basicExecuteImpl(ColumnRawPtrs arguments, ColumnWithTypeAndName & re
            auto converted_column = ColumnUInt8::create(input_rows_count);
            convertColumnToUInt8(column, converted_column->getData());
            uint8_args.push_back(converted_column.get());
-            converted_columns.emplace_back(std::move(converted_column));
+            converted_columns_holder.emplace_back(std::move(converted_column));
        }
    }

-    OperationApplier<Op, AssociativeApplierImpl>::apply(uint8_args, col_res);
-
-    /// This is possible if there is exactly one non-constant among the arguments, and it is of type UInt8.
-    if (uint8_args[0] != col_res.get())
-        vec_res.assign(uint8_args[0]->getData());
+    OperationApplier<Op, AssociativeApplierImpl>::apply(uint8_args, col_res->getData(), has_consts);

    result_info.column = std::move(col_res);
 }
--- a/dbms/src/Functions/FunctionsLogical.h
+++ b/dbms/src/Functions/FunctionsLogical.h
@ -83,12 +83,7 @@ struct XorImpl

    static inline constexpr bool isSaturable() { return false; }
    static inline constexpr bool isSaturatedValue(bool) { return false; }
-    /** Considering that CH uses UInt8 for representation of boolean values this function
-      * returns 255 as "true" but the current implementation of logical functions suggests that
-      * any nonzero value is "true" as well. Also the current code provides no guarantee
-      * for "true" to be represented with the value of 1.
-      */
-    static inline constexpr ResultType apply(UInt8 a, UInt8 b) { return (a != b) ? Ternary::True : Ternary::False; }
+    static inline constexpr ResultType apply(UInt8 a, UInt8 b) { return !!a != !!b; }
    static inline constexpr bool specialImplementationForNulls() { return false; }

 #if USE_EMBEDDED_COMPILER
--- a/dbms/src/Functions/bitCount.cpp
+++ b/dbms/src/Functions/bitCount.cpp
@ -16,7 +16,12 @@ struct BitCountImpl
        /// We count bits in the value representation in memory. For example, we support floats.
        /// We need to avoid sign-extension when converting signed numbers to larger type. So, uint8_t(-1) has 8 bits.

-        return __builtin_popcountll(ext::bit_cast<unsigned long long>(a));
+        if constexpr (std::is_same_v<A, UInt64> || std::is_same_v<A, Int64>)
+            return __builtin_popcountll(a);
+        if constexpr (std::is_same_v<A, UInt32> || std::is_same_v<A, Int32> || std::is_unsigned_v<A>)
+            return __builtin_popcount(a);
+        else
+            return __builtin_popcountll(ext::bit_cast<unsigned long long>(a));
    }

 #if USE_EMBEDDED_COMPILER
--- a/dbms/src/IO/tests/ryu_test.cpp
+++ b/dbms/src/IO/tests/ryu_test.cpp
@ -1,5 +1,6 @@
 #include <string>
 #include <iostream>
+#include <cstring>
 #include <ryu/ryu.h>


--- a/dbms/src/Storages/MergeTree/MergeTreeData.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreeData.cpp
@ -633,6 +633,10 @@ void MergeTreeData::setTTLExpressions(const ColumnsDescription::ColumnTTLs & new

    if (new_ttl_table_ast)
    {
+        std::vector<TTLEntry> update_move_ttl_entries;
+        ASTPtr update_ttl_table_ast = nullptr;
+        TTLEntry update_ttl_table_entry;
+
        bool seen_delete_ttl = false;
        for (auto ttl_element_ptr : new_ttl_table_ast->children)
        {
@ -647,8 +651,8 @@ void MergeTreeData::setTTLExpressions(const ColumnsDescription::ColumnTTLs & new
                auto new_ttl_table_entry = create_ttl_entry(ttl_element.children[0]);
                if (!only_check)
                {
-                    ttl_table_ast = ttl_element.children[0];
-                    ttl_table_entry = new_ttl_table_entry;
+                    update_ttl_table_ast = ttl_element.children[0];
+                    update_ttl_table_entry = new_ttl_table_entry;
                }

                seen_delete_ttl = true;
@ -671,11 +675,18 @@ void MergeTreeData::setTTLExpressions(const ColumnsDescription::ColumnTTLs & new
                }

                if (!only_check)
-                {
-                    move_ttl_entries.emplace_back(std::move(new_ttl_entry));
-                }
+                    update_move_ttl_entries.emplace_back(std::move(new_ttl_entry));
            }
        }
+
+        if (!only_check)
+        {
+            ttl_table_entry = update_ttl_table_entry;
+            ttl_table_ast = update_ttl_table_ast;
+
+            auto move_ttl_entries_lock = std::lock_guard<std::mutex>(move_ttl_entries_mutex);
+            move_ttl_entries = update_move_ttl_entries;
+        }
    }
 }

@ -3293,7 +3304,7 @@ ReservationPtr MergeTreeData::tryReserveSpacePreferringTTLRules(UInt64 expected_
    ReservationPtr reservation;

    auto ttl_entry = selectTTLEntryForTTLInfos(ttl_infos, time_of_move);
-    if (ttl_entry != nullptr)
+    if (ttl_entry)
    {
        SpacePtr destination_ptr = ttl_entry->getDestination(storage_policy);
        if (!destination_ptr)
@ -3352,27 +3363,28 @@ bool MergeTreeData::TTLEntry::isPartInDestination(const StoragePolicyPtr & polic
    return false;
 }

-const MergeTreeData::TTLEntry * MergeTreeData::selectTTLEntryForTTLInfos(
+std::optional<MergeTreeData::TTLEntry> MergeTreeData::selectTTLEntryForTTLInfos(
        const MergeTreeDataPart::TTLInfos & ttl_infos,
        time_t time_of_move) const
 {
-    const MergeTreeData::TTLEntry * result = nullptr;
-    /// Prefer TTL rule which went into action last.
    time_t max_max_ttl = 0;
+    std::vector<DB::MergeTreeData::TTLEntry>::const_iterator best_entry_it;

-    for (const auto & ttl_entry : move_ttl_entries)
+    auto lock = std::lock_guard(move_ttl_entries_mutex);
+    for (auto ttl_entry_it = move_ttl_entries.begin(); ttl_entry_it != move_ttl_entries.end(); ++ttl_entry_it)
    {
-        auto ttl_info_it = ttl_infos.moves_ttl.find(ttl_entry.result_column);
+        auto ttl_info_it = ttl_infos.moves_ttl.find(ttl_entry_it->result_column);
+        /// Prefer TTL rule which went into action last.
        if (ttl_info_it != ttl_infos.moves_ttl.end()
                && ttl_info_it->second.max <= time_of_move
                && max_max_ttl <= ttl_info_it->second.max)
        {
-            result = &ttl_entry;
+            best_entry_it = ttl_entry_it;
            max_max_ttl = ttl_info_it->second.max;
        }
    }

-    return result;
+    return max_max_ttl ? *best_entry_it : std::optional<MergeTreeData::TTLEntry>();
 }

 MergeTreeData::DataParts MergeTreeData::getDataParts(const DataPartStates & affordable_states) const
--- a/dbms/src/Storages/MergeTree/MergeTreeData.h
+++ b/dbms/src/Storages/MergeTree/MergeTreeData.h
@ -737,12 +737,17 @@ public:
        bool isPartInDestination(const StoragePolicyPtr & policy, const MergeTreeDataPart & part) const;
    };

-    const TTLEntry * selectTTLEntryForTTLInfos(const MergeTreeDataPart::TTLInfos & ttl_infos, time_t time_of_move) const;
+    std::optional<TTLEntry> selectTTLEntryForTTLInfos(const MergeTreeDataPart::TTLInfos & ttl_infos, time_t time_of_move) const;

    using TTLEntriesByName = std::unordered_map<String, TTLEntry>;
    TTLEntriesByName column_ttl_entries_by_name;

    TTLEntry ttl_table_entry;
+
+    /// This mutex is required for background move operations which do not obtain global locks.
+    mutable std::mutex move_ttl_entries_mutex;
+
+    /// Vector rw operations have to be done under "move_ttl_entries_mutex".
    std::vector<TTLEntry> move_ttl_entries;

    String sampling_expr_column_name;
--- a/dbms/src/Storages/MergeTree/MergeTreePartsMover.cpp
+++ b/dbms/src/Storages/MergeTree/MergeTreePartsMover.cpp
@ -127,14 +127,14 @@ bool MergeTreePartsMover::selectPartsForMove(
        if (!can_move(part, &reason))
            continue;

-        const MergeTreeData::TTLEntry * ttl_entry_ptr = part->storage.selectTTLEntryForTTLInfos(part->ttl_infos, time_of_move);
+        auto ttl_entry = part->storage.selectTTLEntryForTTLInfos(part->ttl_infos, time_of_move);
        auto to_insert = need_to_move.find(part->disk);
        ReservationPtr reservation;
-        if (ttl_entry_ptr)
+        if (ttl_entry)
        {
-            auto destination = ttl_entry_ptr->getDestination(policy);
-            if (destination && !ttl_entry_ptr->isPartInDestination(policy, *part))
-                reservation = part->storage.tryReserveSpace(part->bytes_on_disk, ttl_entry_ptr->getDestination(policy));
+            auto destination = ttl_entry->getDestination(policy);
+            if (destination && !ttl_entry->isPartInDestination(policy, *part))
+                reservation = part->storage.tryReserveSpace(part->bytes_on_disk, ttl_entry->getDestination(policy));
        }

        if (reservation) /// Found reservation by TTL rule.
--- a/dbms/src/Storages/System/StorageSystemBuildOptions.generated.cpp.in
+++ b/dbms/src/Storages/System/StorageSystemBuildOptions.generated.cpp.in
@ -61,6 +61,7 @@ const char * auto_config_build[]
    "USE_HYPERSCAN", "@USE_HYPERSCAN@",
    "USE_SIMDJSON", "@USE_SIMDJSON@",
    "USE_POCO_REDIS", "@USE_POCO_REDIS@",
+    "USE_REPLXX", "@USE_REPLXX@",

    nullptr, nullptr
 };
--- a/dbms/tests/integration/test_ttl_move/test.py
+++ b/dbms/tests/integration/test_ttl_move/test.py
@ -74,37 +74,37 @@ def test_rule_with_invalid_destination(started_cluster, name, engine, alter):
                    {expression}
                    SETTINGS storage_policy='{policy}'
                """.format(expression=x, name=name, engine=engine, policy=policy)
-    
+
        if alter:
            node1.query(get_command(None, "small_jbod_with_external"))
-    
+
        with pytest.raises(QueryRuntimeException):
            node1.query(get_command("TTL d1 TO DISK 'unknown'", "small_jbod_with_external"))
-    
+
        node1.query("DROP TABLE IF EXISTS {}".format(name))
-    
+
        if alter:
            node1.query(get_command(None, "small_jbod_with_external"))
-    
+
        with pytest.raises(QueryRuntimeException):
            node1.query(get_command("TTL d1 TO VOLUME 'unknown'", "small_jbod_with_external"))
-    
+
        node1.query("DROP TABLE IF EXISTS {}".format(name))
-    
+
        if alter:
            node1.query(get_command(None, "only_jbod2"))
-    
+
        with pytest.raises(QueryRuntimeException):
            node1.query(get_command("TTL d1 TO DISK 'jbod1'", "only_jbod2"))
-    
+
        node1.query("DROP TABLE IF EXISTS {}".format(name))
-    
+
        if alter:
            node1.query(get_command(None, "only_jbod2"))
-    
+
        with pytest.raises(QueryRuntimeException):
            node1.query(get_command("TTL d1 TO VOLUME 'external'", "only_jbod2"))
-    
+
    finally:
        node1.query("DROP TABLE IF EXISTS {}".format(name))

@ -501,13 +501,17 @@ def test_moves_after_merges_work(started_cluster, name, engine, positive):
        node1.query("DROP TABLE IF EXISTS {}".format(name))


-@pytest.mark.parametrize("name,engine,positive", [
-    ("mt_test_moves_after_merges_do_not_work","MergeTree()",0),
-    ("replicated_mt_test_moves_after_merges_do_not_work","ReplicatedMergeTree('/clickhouse/replicated_test_moves_after_merges_do_not_work', '1')",0),
-    ("mt_test_moves_after_merges_work","MergeTree()",1),
-    ("replicated_mt_test_moves_after_merges_work","ReplicatedMergeTree('/clickhouse/replicated_test_moves_after_merges_work', '1')",1),
+@pytest.mark.parametrize("name,engine,positive,bar", [
+    ("mt_test_moves_after_alter_do_not_work","MergeTree()",0,"DELETE"),
+    ("replicated_mt_test_moves_after_alter_do_not_work","ReplicatedMergeTree('/clickhouse/replicated_test_moves_after_alter_do_not_work', '1')",0,"DELETE"),
+    ("mt_test_moves_after_alter_work","MergeTree()",1,"DELETE"),
+    ("replicated_mt_test_moves_after_alter_work","ReplicatedMergeTree('/clickhouse/replicated_test_moves_after_alter_work', '1')",1,"DELETE"),
+    ("mt_test_moves_after_alter_do_not_work","MergeTree()",0,"TO DISK 'external'"),
+    ("replicated_mt_test_moves_after_alter_do_not_work","ReplicatedMergeTree('/clickhouse/replicated_test_moves_after_alter_do_not_work', '1')",0,"TO DISK 'external'"),
+    ("mt_test_moves_after_alter_work","MergeTree()",1,"TO DISK 'external'"),
+    ("replicated_mt_test_moves_after_alter_work","ReplicatedMergeTree('/clickhouse/replicated_test_moves_after_alter_work', '1')",1,"TO DISK 'external'"),
 ])
-def test_ttls_do_not_work_after_alter(started_cluster, name, engine, positive):
+def test_ttls_do_not_work_after_alter(started_cluster, name, engine, positive, bar):
    try:
        node1.query("""
            CREATE TABLE {name} (
@ -523,8 +527,8 @@ def test_ttls_do_not_work_after_alter(started_cluster, name, engine, positive):
            node1.query("""
                ALTER TABLE {name}
                    MODIFY TTL
-                    d1 + INTERVAL 15 MINUTE
-            """.format(name=name)) # That shall disable TTL.
+                    d1 + INTERVAL 15 MINUTE {bar}
+            """.format(name=name, bar=bar)) # That shall disable TTL.

        data = [] # 10MB in total
        for i in range(10):
@ -578,14 +582,14 @@ limitations under the License."""
            ) ENGINE = {engine}
            ORDER BY tuple()
            PARTITION BY p1
-            TTL d1 + INTERVAL 30 SECOND TO DISK 'jbod2', 
+            TTL d1 + INTERVAL 30 SECOND TO DISK 'jbod2',
                d1 + INTERVAL 60 SECOND TO VOLUME 'external'
            SETTINGS storage_policy='jbods_with_external', merge_with_ttl_timeout=0
        """.format(name=name, engine=engine))

        node1.query("""
            ALTER TABLE {name} MODIFY
-            TTL d1 + INTERVAL 0 SECOND TO DISK 'jbod2', 
+            TTL d1 + INTERVAL 0 SECOND TO DISK 'jbod2',
                d1 + INTERVAL 5 SECOND TO VOLUME 'external',
                d1 + INTERVAL 10 SECOND DELETE
        """.format(name=name))
@ -622,6 +626,96 @@ limitations under the License."""
        node1.query("DROP TABLE IF EXISTS {name}".format(name=name))


+@pytest.mark.parametrize("name,engine", [
+    ("concurrently_altering_ttl_mt","MergeTree()"),
+    ("concurrently_altering_ttl_replicated_mt","ReplicatedMergeTree('/clickhouse/concurrently_altering_ttl_replicated_mt', '1')",),
+])
+def test_concurrent_alter_with_ttl_move(started_cluster, name, engine):
+    try:
+        node1.query("""
+            CREATE TABLE {name} (
+                EventDate Date,
+                number UInt64
+            ) ENGINE = {engine}
+            ORDER BY tuple()
+            PARTITION BY toYYYYMM(EventDate)
+            SETTINGS storage_policy='jbods_with_external'
+        """.format(name=name, engine=engine))
+
+        values = list({ random.randint(1, 1000000) for _ in range(0, 1000) })
+
+        def insert(num):
+            for i in range(num):
+                day = random.randint(11, 30)
+                value = values.pop()
+                month = '0' + str(random.choice([3, 4]))
+                node1.query("INSERT INTO {} VALUES(toDate('2019-{m}-{d}'), {v})".format(name, m=month, d=day, v=value))
+
+        def alter_move(num):
+            def produce_alter_move(node, name):
+                move_type = random.choice(["PART", "PARTITION"])
+                if move_type == "PART":
+                    for _ in range(10):
+                        try:
+                            parts = node1.query("SELECT name from system.parts where table = '{}' and active = 1".format(name)).strip().split('\n')
+                            break
+                        except QueryRuntimeException:
+                            pass
+                    else:
+                        raise Exception("Cannot select from system.parts")
+
+                    move_part = random.choice(["'" + part + "'" for part in parts])
+                else:
+                    move_part = random.choice([201903, 201904])
+
+                move_disk = random.choice(["DISK", "VOLUME"])
+                if move_disk == "DISK":
+                    move_volume = random.choice(["'external'", "'jbod1'", "'jbod2'"])
+                else:
+                    move_volume = random.choice(["'main'", "'external'"])
+                try:
+                    node1.query("ALTER TABLE {} MOVE {mt} {mp} TO {md} {mv}".format(
+                        name, mt=move_type, mp=move_part, md=move_disk, mv=move_volume))
+                except QueryRuntimeException as ex:
+                    pass
+
+            for i in range(num):
+                produce_alter_move(node1, name)
+
+        def alter_update(num):
+            for i in range(num):
+                node1.query("ALTER TABLE {} UPDATE number = number + 1 WHERE 1".format(name))
+
+        def alter_modify_ttl(num):
+            for i in range(num):
+                ttls = []
+                for j in range(random.randint(1, 10)):
+                    what = random.choice(["TO VOLUME 'main'", "TO VOLUME 'external'", "TO DISK 'jbod1'", "TO DISK 'jbod2'", "TO DISK 'external'"])
+                    when = "now()+{}".format(random.randint(-1, 5))
+                    ttls.append("{} {}".format(when, what))
+                node1.query("ALTER TABLE {} MODIFY TTL {}".format(name, ", ".join(ttls)))
+
+        def optimize_table(num):
+            for i in range(num):
+                node1.query("OPTIMIZE TABLE {} FINAL".format(name))
+
+        p = Pool(15)
+        tasks = []
+        for i in range(5):
+            tasks.append(p.apply_async(insert, (100,)))
+            tasks.append(p.apply_async(alter_move, (100,)))
+            tasks.append(p.apply_async(alter_update, (100,)))
+            tasks.append(p.apply_async(alter_modify_ttl, (100,)))
+            tasks.append(p.apply_async(optimize_table, (100,)))
+
+        for task in tasks:
+            task.get(timeout=60)
+
+        assert node1.query("SELECT 1") == "1\n"
+        assert node1.query("SELECT COUNT() FROM {}".format(name)) == "500\n"
+    finally:
+        node1.query("DROP TABLE IF EXISTS {name}".format(name=name))
+
@pytest.mark.parametrize("name,positive", [
    ("test_double_move_while_select_negative", 0),
    ("test_double_move_while_select_positive", 1),
--- a/dbms/tests/queries/0_stateless/00552_logical_functions_simple.reference
+++ b/dbms/tests/queries/0_stateless/00552_logical_functions_simple.reference
@ -0,0 +1 @@
+OK
--- a/dbms/tests/queries/0_stateless/00552_logical_functions_simple.sql
+++ b/dbms/tests/queries/0_stateless/00552_logical_functions_simple.sql
@ -0,0 +1,56 @@
+
+-- Test simple logic over smaller batch of columns
+SELECT
+    -- x1, x2, x3, x4,
+    xor(x1, x2, x3, x4) AS xor1,
+    xor(xor(x1, x2), xor(x3, x4)) AS xor2,
+
+    or(x1, x2, x3, x4) AS or1,
+    or(x1 or x2, x3 or x4) AS or2,
+
+    and(x1, x2, x3, x4) AS and1,
+    and(x1 and x2, x3 and x4) AS and2
+FROM (
+    SELECT
+        toUInt8(number % 2) AS x1,
+        toUInt8(number / 2 % 2) AS x2,
+        toUInt8(number / 4 % 2) AS x3,
+        toUInt8(number / 8 % 2) AS x4
+    FROM numbers(16)
+)
+WHERE
+    xor1 != xor2 OR (and1 != and2 OR or1 != or2)
+;
+
+-- Test simple logic over multiple batches of columns (currently batch spans over 10 columns)
+SELECT
+    -- x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11,
+    xor(x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11) AS xor1,
+    xor(x1, xor(xor(xor(x2, x3), xor(x4, x5)), xor(xor(x6, x7), xor(x8, xor(x9, xor(x10, x11)))))) AS xor2,
+
+    or(x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11) AS or1,
+    or(x1, or(or(or(x2, x3), or(x4, x5)), or(or(x6, x7), or(x8, or(x9, or(x10, x11)))))) AS or2,
+
+    and(x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11) AS and1,
+    and(x1, and((x2 and x3) and (x4 and x5), (x6 and x7) and (x8 and (x9 and (x10 and x11))))) AS and2
+FROM (
+    SELECT
+        toUInt8(number % 2) AS x1,
+        toUInt8(number / 2 % 2) AS x2,
+        toUInt8(number / 4 % 2) AS x3,
+        toUInt8(number / 8 % 2) AS x4,
+        toUInt8(number / 16 % 2) AS x5,
+        toUInt8(number / 32 % 2) AS x6,
+        toUInt8(number / 64 % 2) AS x7,
+        toUInt8(number / 128 % 2) AS x8,
+        toUInt8(number / 256 % 2) AS x9,
+        toUInt8(number / 512 % 2) AS x10,
+        toUInt8(number / 1024 % 2) AS x11
+    FROM numbers(2048)
+)
+WHERE
+    xor1 != xor2 OR (and1 != and2 OR or1 != or2)
+;
+
+
+SELECT 'OK';
--- a/dbms/tests/queries/0_stateless/00552_logical_functions_ternary.reference
+++ b/dbms/tests/queries/0_stateless/00552_logical_functions_ternary.reference
@ -0,0 +1 @@
+OK
--- a/dbms/tests/queries/0_stateless/00552_logical_functions_ternary.sql
+++ b/dbms/tests/queries/0_stateless/00552_logical_functions_ternary.sql
@ -0,0 +1,59 @@
+
+-- Tests codepath for ternary logic
+SELECT
+    -- x1, x2, x3, x4,
+    xor(x1, x2, x3, x4) AS xor1,
+    xor(xor(x1, x2), xor(x3, x4)) AS xor2,
+
+    or(x1, x2, x3, x4) AS or1,
+    or(x1 or x2, x3 or x4) AS or2,
+
+    and(x1, x2, x3, x4) AS and1,
+    and(x1 and x2, x3 and x4) AS and2
+FROM (
+    SELECT
+        nullIf(toUInt8(number % 3), 2) AS x1,
+        nullIf(toUInt8(number / 3 % 3), 2) AS x2,
+        nullIf(toUInt8(number / 9 % 3), 2) AS x3,
+        nullIf(toUInt8(number / 27 % 3), 2) AS x4
+    FROM numbers(81)
+)
+WHERE
+    (xor1 != xor2 OR (xor1 is NULL) != (xor2 is NULL)) OR
+    (or1 != or2 OR (or1 is NULL) != (or2 is NULL) OR (and1 != and2 OR (and1 is NULL) != (and2 is NULL)))
+;
+
+
+-- Test ternary logic over multiple batches of columns (currently batch spans over 10 columns)
+SELECT
+    -- x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11,
+    xor(x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11) AS xor1,
+    xor(x1, xor(xor(xor(x2, x3), xor(x4, x5)), xor(xor(x6, x7), xor(x8, xor(x9, xor(x10, x11)))))) AS xor2,
+
+    or(x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11) AS or1,
+    or(x1, or(or(or(x2, x3), or(x4, x5)), or(or(x6, x7), or(x8, or(x9, or(x10, x11)))))) AS or2,
+
+    and(x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11) AS and1,
+    and(x1, and((x2 and x3) and (x4 and x5), (x6 and x7) and (x8 and (x9 and (x10 and x11))))) AS and2
+FROM (
+    SELECT
+        nullIf(toUInt8(number % 3), 2) AS x1,
+        nullIf(toUInt8(number / 3 % 3), 2) AS x2,
+        nullIf(toUInt8(number / 9 % 3), 2) AS x3,
+        nullIf(toUInt8(number / 27 % 3), 2) AS x4,
+        nullIf(toUInt8(number / 81 % 3), 2) AS x5,
+        nullIf(toUInt8(number / 243 % 3), 2) AS x6,
+        nullIf(toUInt8(number / 729 % 3), 2) AS x7,
+        nullIf(toUInt8(number / 2187 % 3), 2) AS x8,
+        nullIf(toUInt8(number / 6561 % 3), 2) AS x9,
+        nullIf(toUInt8(number / 19683 % 3), 2) AS x10,
+        nullIf(toUInt8(number / 59049 % 3), 2) AS x11
+    FROM numbers(177147)
+)
+WHERE
+    (xor1 != xor2 OR (xor1 is NULL) != (xor2 is NULL)) OR
+    (or1 != or2 OR (or1 is NULL) != (or2 is NULL) OR (and1 != and2 OR (and1 is NULL) != (and2 is NULL)))
+;
+
+
+SELECT 'OK';
--- a/dbms/tests/queries/0_stateless/01068_parens.reference
+++ b/dbms/tests/queries/0_stateless/01068_parens.reference
@ -0,0 +1 @@
+1
--- a/dbms/tests/queries/0_stateless/01068_parens.sql
+++ b/dbms/tests/queries/0_stateless/01068_parens.sql
@ -0,0 +1 @@
+((((((((((((((SELECT((((((((((((((((((((((((((((((((1))))))))))))))))))))))))))))))))))))))))))))))
--- a/docs/en/interfaces/mysql.md
+++ b/docs/en/interfaces/mysql.md
@ -0,0 +1,35 @@
+# MySQL interface {#mysql_interface}
+
+ClickHouse supports MySQL wire protocol. It can be enabled by [mysql_port](../operations/server_settings/settings.md#server_settings-mysql_port) setting in configuration file:
+```xml
+<mysql_port>9004</mysql_port>
+```
+
+Example of connecting using command-line tool mysql:
+```bash
+$ mysql --protocol tcp -u default -P 9004
+```
+
+Output if connection succeeded:
+```text
+Welcome to the MySQL monitor.  Commands end with ; or \g.
+Your MySQL connection id is 4
+Server version: 20.2.1.1-ClickHouse
+
+Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
+
+Oracle is a registered trademark of Oracle Corporation and/or its
+affiliates. Other names may be trademarks of their respective
+owners.
+
+Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
+
+mysql> 
+```
+
+For compatibility with all MySQL clients, it is recommended to specify user password with [double SHA1](../operations/settings/settings_users.md#password_double_sha1_hex) in configuration file.
+If user password is specified using [SHA256](../operations/settings/settings_users.md#password_sha256_hex), some  clients won't be able to authenticate (mysqljs and old versions of command-line tool mysql).
+
+Restrictions:
+- prepared queries are not supported
+- some data types are sent as strings
--- a/docs/en/interfaces/third-party/gui.md
+++ b/docs/en/interfaces/third-party/gui.md
@ -88,18 +88,6 @@ Features:

 ## Commercial

-### Holistics Software
-
-[Holistics](https://www.holistics.io/) was listed by Gartner's Frontrunners in 2019 as one of the top 2 highest ranked business intelligence tools globally for usability. Holistics is a full-stack data platform and business intelligence tool for setting up your analytics processes, built on SQL. 
-
-Features:
-
- Automated email, Slack and Google Sheet schedules of reports.
- Powerful SQL editor with visualizations, version control, auto-completion, reusable query components and dynamic filters.
- Embedded analytics of reports and dashboards via iframe.
- Data preparation and ETL capabilities.
- SQL data modeling support for relational mapping of data.
-
 ### DataGrip

 [DataGrip](https://www.jetbrains.com/datagrip/) is a database IDE from JetBrains with dedicated support for ClickHouse. It is also embedded into other IntelliJ-based tools: PyCharm, IntelliJ IDEA, GoLand, PhpStorm and others.
@ -113,6 +101,18 @@ Features:
 - Refactorings.
 - Search and Navigation.

+### Holistics Software
+
+[Holistics](https://www.holistics.io/) is a full-stack data platform and business intelligence tool. 
+
+Features:
+
+- Automated email, Slack and Google Sheet schedules of reports.
+- SQL editor with visualizations, version control, auto-completion, reusable query components and dynamic filters.
+- Embedded analytics of reports and dashboards via iframe.
+- Data preparation and ETL capabilities.
+- SQL data modeling support for relational mapping of data.
+
 ### Looker
 [Looker](https://looker.com) is a data platform and business intelligence tool with support for 50+ database dialects including ClickHouse. Looker is available as a SaaS platform and self-hosted. Users
 can use Looker via the browser to explore data, build visualizations and dashboards, schedule reports, and share their
--- a/docs/en/operations/server_settings/settings.md
+++ b/docs/en/operations/server_settings/settings.md
@ -709,6 +709,20 @@ Positive integer.
 <tcp_port_secure>9440</tcp_port_secure>
 ```

+## mysql_port {#server_settings-mysql_port}
+
+Port for communicating with clients over MySQL protocol.
+
+**Possible values**
+
+Positive integer.
+
+Example
+
+```xml
+<mysql_port>9004</mysql_port>
+```
+
 ## tmp_path

 Path to temporary data for processing large queries.
--- a/docs/en/operations/settings/settings_users.md
+++ b/docs/en/operations/settings/settings_users.md
@ -33,12 +33,14 @@ Structure of the `users` section:

 ### user_name/password

-Password could be specified in plaintext or in SHA256 (hex format).
+Password can be specified in plaintext or in SHA256 (hex format).

 - To assign a password in plaintext (**not recommended**), place it in a `password` element.

    For example, `<password>qwerty</password>`. The password can be left blank.

+<a id="password_sha256_hex"></a>
+
 - To assign a password using its SHA256 hash, place it in a `password_sha256_hex` element.

    For example, `<password_sha256_hex>65e84be33532fb784c48129675f9eff3a682b27168c0ea744b2cf58ee02337c5</password_sha256_hex>`.
@ -51,6 +53,19 @@ Password could be specified in plaintext or in SHA256 (hex format).

    The first line of the result is the password. The second line is the corresponding SHA256 hash.

+<a id="password_double_sha1_hex"></a>
+
+- For compatibility with MySQL clients, password can be specified in double SHA1 hash. Place it in `password_double_sha1_hex` element.
+
+    For example, `<password_double_sha1_hex>08b4a0f1de6ad37da17359e592c8d74788a83eb0</password_double_sha1_hex>`.
+
+    Example of how to generate a password from shell:
+
+    ```
+    PASSWORD=$(base64 < /dev/urandom | head -c8); echo "$PASSWORD"; echo -n "$PASSWORD" | openssl dgst -sha1 -binary | openssl dgst -sha1
+    ```
+
+    The first line of the result is the password. The second line is the corresponding double SHA1 hash.

 ### user_name/networks

--- a/docs/ru/interfaces/mysql.md
+++ b/docs/ru/interfaces/mysql.md
@ -0,0 +1,35 @@
+# MySQL-интерфейс {#mysql_interface}
+
+ClickHouse поддерживает взаимодействие по протоколу MySQL. Данная функция включается настройкой [mysql_port](../operations/server_settings/settings.md#server_settings-mysql_port) в конфигурационном файле:
+```xml
+<mysql_port>9004</mysql_port>
+```
+
+Пример подключения с помощью стандартного клиента mysql:
+```bash
+$ mysql --protocol tcp -u default -P 9004
+```
+
+Вывод в случае успешного подключения:
+```text
+Welcome to the MySQL monitor.  Commands end with ; or \g.
+Your MySQL connection id is 4
+Server version: 20.2.1.1-ClickHouse
+
+Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
+
+Oracle is a registered trademark of Oracle Corporation and/or its
+affiliates. Other names may be trademarks of their respective
+owners.
+
+Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
+
+mysql> 
+```
+
+Для совместимости со всеми клиентами рекомендуется задавать пароль пользователя в конфигурационном файле с помощью двойного хэша [SHA1](../operations/settings/settings_users.md#password_double_sha1_hex).
+В случае указания пароля с помощью [SHA256](../operations/settings/settings_users.md#password_sha256_hex) некоторые клиенты не смогут пройти аутентификацию (mysqljs и старые версии стандартного клиента mysql).
+
+Ограничения:
+- не поддерживаются подготовленные запросы
+- некоторые типы данных отправляются как строки
--- a/docs/ru/interfaces/third-party/gui.md
+++ b/docs/ru/interfaces/third-party/gui.md
@ -91,18 +91,6 @@

 ## Коммерческие

-### Holistics Software
-
-[Holistics](https://www.holistics.io/) вошёл в топ-2 наиболее удобных инструментов для бизнес-аналитики по рейтингу Gartner's Frontrunners в 2019 году. Holistics — full-stack платформа для обработки данных и инструмент бизнес-аналитики, позволяющий вам построить свои процессы с помощью SQL.
-
-Основные возможности:
-
- Автоматизированные отчёты на почту, Slack, и Google Sheet.
- Мощный редактор SQL c визуализацией, контролем версий, автодополнением, повторным использованием частей запроса и динамическими фильтрами.
- Встроенные инструменты анализа отчётов и всплывающие (iframe) дашборды.
- Подготовка данных и возможности ETL.
- Моделирование данных с помощью SQL для их реляционного отображения.
-
 ### DataGrip

 [DataGrip](https://www.jetbrains.com/datagrip/) — это IDE для баз данных о JetBrains с выделенной поддержкой ClickHouse. Он также встроен в другие инструменты на основе IntelliJ: PyCharm, IntelliJ IDEA, GoLand, PhpStorm и другие.
@ -116,4 +104,16 @@
 - Рефакторинги.
 - Поиск и навигация.

+### Holistics Software
+
+[Holistics](https://www.holistics.io/) — full-stack платформа для обработки данных и бизнес-аналитики.
+
+Основные возможности:
+
+- Автоматизированные отчёты на почту, Slack, и Google Sheet.
+- Редактор SQL c визуализацией, контролем версий, автодополнением, повторным использованием частей запроса и динамическими фильтрами.
+- Встроенные инструменты анализа отчётов и всплывающие (iframe) дашборды.
+- Подготовка данных и возможности ETL.
+- Моделирование данных с помощью SQL для их реляционного отображения.
+
 [Оригинальная статья](https://clickhouse.yandex/docs/ru/interfaces/third-party/gui/) <!--hide-->
--- a/docs/ru/operations/server_settings/settings.md
+++ b/docs/ru/operations/server_settings/settings.md
@ -661,6 +661,16 @@ TCP порт для защищённого обмена данными с кли
 <tcp_port_secure>9440</tcp_port_secure>
 ```

+## mysql_port {#server_settings-mysql_port}
+
+Порт для взаимодействия с клиентами по протоколу MySQL.
+
+Пример
+
+```xml
+<mysql_port>9004</mysql_port>
+```
+
 ## tmp_path

 Путь ко временным данным для обработки больших запросов.
--- a/docs/ru/operations/settings/settings_users.md
+++ b/docs/ru/operations/settings/settings_users.md
@ -39,6 +39,8 @@

    Например, `<password>qwerty</password>`. Пароль можно оставить пустым.

+<a id="password_sha256_hex"></a>
+
 - Чтобы назначить пароль в виде SHA256, поместите хэш в элемент `password_sha256_hex`.

    Например, `<password_sha256_hex>65e84be33532fb784c48129675f9eff3a682b27168c0ea744b2cf58ee02337c5</password_sha256_hex>`.
@ -51,6 +53,20 @@

    Первая строка результата — пароль. Вторая строка — соответствующий ему хэш SHA256.

+<a id="password_double_sha1_hex"></a>
+
+- Для совместимости с клиентами MySQL, пароль можно задать с помощью двойного хэша SHA1, поместив его в элемент `password_double_sha1_hex`.
+
+    Например, `<password_double_sha1_hex>08b4a0f1de6ad37da17359e592c8d74788a83eb0</password_double_sha1_hex>`.
+
+    Пример создания пароля в командной строке:
+
+    ```
+    PASSWORD=$(base64 < /dev/urandom | head -c8); echo "$PASSWORD"; echo -n "$PASSWORD" | openssl dgst -sha1 -binary | openssl dgst -sha1
+    ```
+
+    Первая строка результата — пароль. Вторая строка — соответствующий ему двойной хэш SHA1.
+
 ### user_name/networks

 Список сетей, из которых пользователь может подключиться к серверу ClickHouse.
--- a/docs/toc_en.yml
+++ b/docs/toc_en.yml
@ -25,6 +25,7 @@ nav:
  - 'Command-Line Client': 'interfaces/cli.md'
  - 'Native Interface (TCP)': 'interfaces/tcp.md'
  - 'HTTP Interface': 'interfaces/http.md'
+  - 'MySQL Interface': 'interfaces/mysql.md'
  - 'Input and Output Formats': 'interfaces/formats.md'
  - 'JDBC Driver': 'interfaces/jdbc.md'
  - 'ODBC Driver': 'interfaces/odbc.md'
--- a/docs/toc_ru.yml
+++ b/docs/toc_ru.yml
@ -26,6 +26,7 @@ nav:
  - 'Клиент командной строки': 'interfaces/cli.md'
  - 'Нативный интерфейс (TCP)': 'interfaces/tcp.md'
  - 'HTTP-интерфейс': 'interfaces/http.md'
+  - 'MySQL-интерфейс': 'interfaces/mysql.md'
  - 'Форматы входных и выходных данных': 'interfaces/formats.md'
  - 'JDBC-драйвер': 'interfaces/jdbc.md'
  - 'ODBC-драйвер': 'interfaces/odbc.md'
--- a/libs/libcommon/CMakeLists.txt
+++ b/libs/libcommon/CMakeLists.txt
@ -104,7 +104,7 @@ if(CCTZ_LIBRARY)
    target_link_libraries(common PRIVATE ${CCTZ_LIBRARY})
 endif()

-if (ENABLE_REPLXX)
+if (USE_REPLXX)
    target_link_libraries(common PRIVATE replxx)
 endif ()

--- a/libs/libcommon/include/common/config_common.h.in
+++ b/libs/libcommon/include/common/config_common.h.in
@ -3,5 +3,6 @@
 // .h autogenerated by cmake !

 #cmakedefine01 USE_JEMALLOC
+#cmakedefine01 USE_REPLXX
 #cmakedefine01 UNBUNDLED
 #cmakedefine01 WITH_COVERAGE
--- a/libs/libcommon/src/ReplxxLineReader.cpp
+++ b/libs/libcommon/src/ReplxxLineReader.cpp
@ -27,12 +27,9 @@ ReplxxLineReader::ReplxxLineReader(const Suggest * suggest, const String & histo
        return replxx::Replxx::completions_t(range.first, range.second);
    };

-    if (suggest)
-    {
-        rx.set_completion_callback(callback);
-        rx.set_complete_on_empty(false);
-        rx.set_word_break_characters(word_break_characters);
-    }
+    rx.set_completion_callback(callback);
+    rx.set_complete_on_empty(false);
+    rx.set_word_break_characters(word_break_characters);
 }

 ReplxxLineReader::~ReplxxLineReader()
				`@ -0,0 +1 @@`
				`((((((((((((((SELECT((((((((((((((((((((((((((((((((1))))))))))))))))))))))))))))))))))))))))))))))`