Merge

2024-11-22 15:42:02 +00:00 · 2020-08-08 17:20:50 +00:00 · 2020-08-08 17:20:50 +00:00 · 139a19d583
commit 139a19d583
parent 2ea32a710a beed3c8244
493 changed files with 6827 additions and 5935 deletions
--- a/.gitignore
+++ b/.gitignore
@ -79,6 +79,7 @@ configure-stamp
 *.bin
 *.mrk
 *.mrk2
+*.mrk3

 .dupload.conf

--- a/.gitmodules
+++ b/.gitmodules
@ -91,10 +91,10 @@
 	url = https://github.com/ClickHouse-Extras/libunwind.git
 [submodule "contrib/simdjson"]
 	path = contrib/simdjson
-	url = https://github.com/lemire/simdjson.git
+	url = https://github.com/ClickHouse-Extras/simdjson.git
 [submodule "contrib/rapidjson"]
 	path = contrib/rapidjson
-	url = https://github.com/Tencent/rapidjson
+	url = https://github.com/ClickHouse-Extras/rapidjson
 [submodule "contrib/fastops"]
 	path = contrib/fastops
 	url = https://github.com/ClickHouse-Extras/fastops
@ -173,7 +173,7 @@
 	url = https://github.com/fmtlib/fmt.git
 [submodule "contrib/sentry-native"]
 	path = contrib/sentry-native
-	url = https://github.com/getsentry/sentry-native.git
+	url = https://github.com/ClickHouse-Extras/sentry-native.git
 [submodule "contrib/gcem"]
 	path = contrib/gcem
 	url = https://github.com/kthohr/gcem.git
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -176,10 +176,7 @@ if(NOT DISABLE_CPU_OPTIMIZE)
    include(cmake/cpu_features.cmake)
 endif()

-if(NOT COMPILER_CLANG) # clang: error: the clang compiler does not support '-march=native'
-    option(ARCH_NATIVE "Enable -march=native compiler flag" ${ARCH_ARM})
-endif()
-
+option(ARCH_NATIVE "Enable -march=native compiler flag" 0)
 if (ARCH_NATIVE)
    set (COMPILER_FLAGS "${COMPILER_FLAGS} -march=native")
 endif ()
--- a/README.md
+++ b/README.md
@ -10,6 +10,7 @@ ClickHouse is an open-source column-oriented database management system that all
 * [YouTube channel](https://www.youtube.com/c/ClickHouseDB) has a lot of content about ClickHouse in video format.
 * [Slack](https://join.slack.com/t/clickhousedb/shared_invite/zt-d2zxkf9e-XyxDa_ucfPxzuH4SJIm~Ng) and [Telegram](https://telegram.me/clickhouse_en) allow to chat with ClickHouse users in real-time.
 * [Blog](https://clickhouse.yandex/blog/en/) contains various ClickHouse-related articles, as well as announcements and reports about events.
+* [Code Browser](https://clickhouse.tech/codebrowser/html_report/ClickHouse/index.html) with syntax highlight and navigation.
 * [Yandex.Messenger channel](https://yandex.ru/chat/#/join/20e380d9-c7be-4123-ab06-e95fb946975e) shares announcements and useful links in Russian.
 * [Contacts](https://clickhouse.tech/#contacts) can help to get your questions answered if there are any.
 * You can also [fill this form](https://clickhouse.tech/#meet) to meet Yandex ClickHouse team in person.
--- a/base/common/DateLUTImpl.h
+++ b/base/common/DateLUTImpl.h
@ -404,7 +404,7 @@ public:
        a date at start of january) In this case one can get 53 for the
        first week of next year.  This flag ensures that the week is
        relevant for the given year. Note that this flag is only
-        releveant if WeekModeFlag::JANUARY is not set.
+        relevant if WeekModeFlag::JANUARY is not set.

                  If set Week is in range 1-53.

--- a/base/common/tests/gtest_json_test.cpp
+++ b/base/common/tests/gtest_json_test.cpp
--- a/base/daemon/BaseDaemon.cpp
+++ b/base/daemon/BaseDaemon.cpp
@ -51,6 +51,7 @@
 #include <Common/getMultipleKeysFromConfig.h>
 #include <Common/ClickHouseRevision.h>
 #include <Common/Config/ConfigProcessor.h>
+#include <Common/MemorySanitizer.h>
 #include <Common/SymbolIndex.h>

 #if !defined(ARCADIA_BUILD)
@ -76,6 +77,15 @@ static void call_default_signal_handler(int sig)
    raise(sig);
 }

+const char * msan_strsignal(int sig)
+{
+    // Apparently strsignal is not instrumented by MemorySanitizer, so we
+    // have to unpoison it to avoid msan reports inside fmt library when we
+    // print it.
+    const char * signal_name = strsignal(sig);
+    __msan_unpoison_string(signal_name);
+    return signal_name;
+}

 static constexpr size_t max_query_id_size = 127;

@ -280,12 +290,14 @@ private:
        if (query_id.empty())
        {
            LOG_FATAL(log, "(version {}{}, {}) (from thread {}) (no query) Received signal {} ({})",
-                VERSION_STRING, VERSION_OFFICIAL, daemon.build_id_info, thread_num, strsignal(sig), sig);
+                VERSION_STRING, VERSION_OFFICIAL, daemon.build_id_info,
+                thread_num, msan_strsignal(sig), sig);
        }
        else
        {
            LOG_FATAL(log, "(version {}{}, {}) (from thread {}) (query_id: {}) Received signal {} ({})",
-                VERSION_STRING, VERSION_OFFICIAL, daemon.build_id_info, thread_num, query_id, strsignal(sig), sig);
+                VERSION_STRING, VERSION_OFFICIAL, daemon.build_id_info,
+                thread_num, query_id, msan_strsignal(sig), sig);
        }

        String error_message;
@ -833,13 +845,13 @@ void BaseDaemon::handleSignal(int signal_id)
        onInterruptSignals(signal_id);
    }
    else
-        throw DB::Exception(std::string("Unsupported signal: ") + strsignal(signal_id), 0);
+        throw DB::Exception(std::string("Unsupported signal: ") + msan_strsignal(signal_id), 0);
 }

 void BaseDaemon::onInterruptSignals(int signal_id)
 {
    is_cancelled = true;
-    LOG_INFO(&logger(), "Received termination signal ({})", strsignal(signal_id));
+    LOG_INFO(&logger(), "Received termination signal ({})", msan_strsignal(signal_id));

    if (sigint_signals_counter >= 2)
    {
--- a/base/daemon/BaseDaemon.h
+++ b/base/daemon/BaseDaemon.h
@ -29,7 +29,7 @@
 namespace Poco { class TaskManager; }


-/// \brief Base class for applications that can run as deamons.
+/// \brief Base class for applications that can run as daemons.
 ///
 /// \code
 /// # Some possible command line options:
--- a/base/daemon/SentryWriter.cpp
+++ b/base/daemon/SentryWriter.cpp
@ -46,7 +46,7 @@ void setExtras()
    sentry_set_extra("version_patch", sentry_value_new_int32(VERSION_PATCH));
 }

-void sentry_logger(sentry_level_t level, const char * message, va_list args)
+void sentry_logger(sentry_level_e level, const char * message, va_list args, void *)
 {
    auto * logger = &Poco::Logger::get("SentryWriter");
    size_t size = 1024;
@ -107,7 +107,7 @@ void SentryWriter::initialize(Poco::Util::LayeredConfiguration & config)

        sentry_options_t * options = sentry_options_new();  /// will be freed by sentry_init or sentry_shutdown
        sentry_options_set_release(options, VERSION_STRING_SHORT);
-        sentry_options_set_logger(options, &sentry_logger);
+        sentry_options_set_logger(options, &sentry_logger, nullptr);
        if (debug)
        {
            sentry_options_set_debug(options, 1);
--- a/base/ext/chrono_io.h
+++ b/base/ext/chrono_io.h
@ -26,12 +26,12 @@ namespace ext
    }

    template <typename Rep, typename Period = std::ratio<1>>
-    std::string to_string(const std::chrono::duration<Rep, Period> & dur)
+    std::string to_string(const std::chrono::duration<Rep, Period> & duration)
    {
-        auto seconds_as_int = std::chrono::duration_cast<std::chrono::seconds>(dur);
-        if (seconds_as_int == dur)
+        auto seconds_as_int = std::chrono::duration_cast<std::chrono::seconds>(duration);
+        if (seconds_as_int == duration)
            return std::to_string(seconds_as_int.count()) + "s";
-        auto seconds_as_double = std::chrono::duration_cast<std::chrono::duration<double>>(dur);
+        auto seconds_as_double = std::chrono::duration_cast<std::chrono::duration<double>>(duration);
        return std::to_string(seconds_as_double.count()) + "s";
    }

@ -42,8 +42,8 @@ namespace ext
    }

    template <typename Rep, typename Period = std::ratio<1>>
-    std::ostream & operator<<(std::ostream & o, const std::chrono::duration<Rep, Period> & dur)
+    std::ostream & operator<<(std::ostream & o, const std::chrono::duration<Rep, Period> & duration)
    {
-        return o << to_string(dur);
+        return o << to_string(duration);
    }
 }
--- a/base/glibc-compatibility/musl/lgamma.c
+++ b/base/glibc-compatibility/musl/lgamma.c
@ -24,7 +24,7 @@
 *                          = log(6.3*5.3) + lgamma(5.3)
 *                          = log(6.3*5.3*4.3*3.3*2.3) + lgamma(2.3)
 *   2. Polynomial approximation of lgamma around its
- *      minimun ymin=1.461632144968362245 to maintain monotonicity.
+ *      minimum ymin=1.461632144968362245 to maintain monotonicity.
 *      On [ymin-0.23, ymin+0.27] (i.e., [1.23164,1.73163]), use
 *              Let z = x-ymin;
 *              lgamma(x) = -1.214862905358496078218 + z^2*poly(z)
--- a/base/loggers/Loggers.h
+++ b/base/loggers/Loggers.h
@ -21,7 +21,7 @@ public:

    std::optional<size_t> getLayer() const
    {
-        return layer; /// layer setted in inheritor class BaseDaemonApplication.
+        return layer; /// layer set in inheritor class BaseDaemonApplication.
    }

    void setTextLog(std::shared_ptr<DB::TextLog> log, int max_priority);
--- a/base/loggers/OwnSplitChannel.cpp
+++ b/base/loggers/OwnSplitChannel.cpp
@ -91,10 +91,13 @@ void OwnSplitChannel::logSplit(const Poco::Message & msg)
            elem.source_file = msg.getSourceFile();

        elem.source_line = msg.getSourceLine();
-
+        std::shared_ptr<TextLog> text_log_locked{};
+        {
            std::lock_guard<std::mutex> lock(text_log_mutex);
-        if (auto log = text_log.lock())
-            log->add(elem);
+            text_log_locked = text_log.lock();
+        }
+        if (text_log_locked)
+            text_log_locked->add(elem);
    }
 }

--- a/base/mysqlxx/mysqlxx.h
+++ b/base/mysqlxx/mysqlxx.h
@ -53,8 +53,6 @@
  * These assumptions are specific for Yandex.Metrica. Your mileage may vary.
  *
  * mysqlxx could not be considered as separate full-featured library,
-  *  because it is developed from the principle - "everything that we don't need is not implemented",
-  *  and also the library depends on some other libraries from Yandex.Metrica code.
-  *  (dependencied could be easily removed if necessary).
+  *  because it is developed from the principle - "everything that we don't need is not implemented".
  * It is assumed that the user will add all missing functionality that is needed.
  */
--- a/base/pcg-random/pcg_extras.hpp
+++ b/base/pcg-random/pcg_extras.hpp
@ -110,7 +110,7 @@ namespace pcg_extras {
 /*
 * C++ requires us to be able to serialize RNG state by printing or reading
 * it from a stream.  Because we use 128-bit ints, we also need to be able
- * ot print them, so here is code to do so.
+ * or print them, so here is code to do so.
 *
 * This code provides enough functionality to print 128-bit ints in decimal
 * and zero-padded in hex.  It's not a full-featured implementation.
@ -253,7 +253,7 @@ inline std::istream& operator>>(std::istream& in, uint8_t& value)
 */

 /*
- * XorShifts are invertable, but they are someting of a pain to invert.
+ * XorShifts are invertable, but they are something of a pain to invert.
 * This function backs them out.  It's used by the whacky "inside out"
 * generator defined later.
 */
--- a/base/pcg-random/pcg_random.hpp
+++ b/base/pcg-random/pcg_random.hpp
@ -174,7 +174,7 @@ PCG_DEFINE_CONSTANT(pcg128_t, default, increment,
 *                       period
 *     specific stream - the constant can be changed at any time, selecting
 *                       a different random sequence
- *     unique stream   - the constant is based on the memory addresss of the
+ *     unique stream   - the constant is based on the memory address of the
 *                       object, thus every RNG has its own unique sequence
 *
 * This variation is provided though mixin classes which define a function
@ -352,7 +352,7 @@ protected:
 * (reducing register pressure).
 *
 * Given the high level of parameterization, the code has to use some
- * template-metaprogramming tricks to handle some of the suble variations
+ * template-metaprogramming tricks to handle some of the subtle variations
 * involved.
 */

--- a/cmake/autogenerated_versions.txt
+++ b/cmake/autogenerated_versions.txt
@ -1,9 +1,9 @@
 # This strings autochanged from release_lib.sh:
-SET(VERSION_REVISION 54437)
+SET(VERSION_REVISION 54438)
 SET(VERSION_MAJOR 20)
-SET(VERSION_MINOR 7)
+SET(VERSION_MINOR 8)
 SET(VERSION_PATCH 1)
-SET(VERSION_GITHASH d64e51d1a78c1b53c33915ca0f75c97b2333844f)
-SET(VERSION_DESCRIBE v20.7.1.1-prestable)
-SET(VERSION_STRING 20.7.1.1)
+SET(VERSION_GITHASH 5d60ab33a511efd149c7c3de77c0dd4b81e65b13)
+SET(VERSION_DESCRIBE v20.8.1.1-prestable)
+SET(VERSION_STRING 20.8.1.1)
 # end of autochange
--- a/cmake/warnings.cmake
+++ b/cmake/warnings.cmake
@ -20,6 +20,12 @@ endif ()

 option (WEVERYTHING "Enables -Weverything option with some exceptions. This is intended for exploration of new compiler warnings that may be found to be useful. Only makes sense for clang." ON)

+# Control maximum size of stack frames. It can be important if the code is run in fibers with small stack size.
+# Only in release build because debug has too large stack frames.
+if ((NOT CMAKE_BUILD_TYPE_UC STREQUAL "DEBUG") AND (NOT SANITIZE))
+    add_warning(frame-larger-than=16384)
+endif ()
+
 if (COMPILER_CLANG)
    add_warning(pedantic)
    no_warning(vla-extension)
--- a/contrib/rapidjson
+++ b/contrib/rapidjson
@ -1 +1 @@
-Subproject commit 8f4c021fa2f1e001d2376095928fc0532adf2ae6
+Subproject commit c4ef90ccdbc21d5d5a628d08316bfd301e32d6fa
--- a/contrib/sentry-native
+++ b/contrib/sentry-native
@ -1 +1 @@
-Subproject commit f91ed3f95b5653f247189d720ab00765b4899d6f
+Subproject commit 94644e92f0a3ff14bd35ed902a8622a2d15f7be4
--- a/contrib/simdjson
+++ b/contrib/simdjson
@ -1 +1 @@
-Subproject commit 1e4aa116e5a39e4ba23b9a93e6c7f048c5105b20
+Subproject commit 3190d66a49059092a1753dc35595923debfc1698
--- a/debian/changelog
+++ b/debian/changelog
@ -1,5 +1,5 @@
-clickhouse (20.7.1.1) unstable; urgency=low
+clickhouse (20.8.1.1) unstable; urgency=low

  * Modified source code

- -- clickhouse-release <clickhouse-release@yandex-team.ru>  Mon, 13 Jul 2020 18:25:58 +0300
+ -- clickhouse-release <clickhouse-release@yandex-team.ru>  Fri, 07 Aug 2020 21:45:46 +0300
--- a/docker/client/Dockerfile
+++ b/docker/client/Dockerfile
@ -1,7 +1,7 @@
 FROM ubuntu:18.04

 ARG repository="deb https://repo.clickhouse.tech/deb/stable/ main/"
-ARG version=20.7.1.*
+ARG version=20.8.1.*

 RUN apt-get update \
    && apt-get install --yes --no-install-recommends \
--- a/docker/packager/deb/Dockerfile
+++ b/docker/packager/deb/Dockerfile
@ -21,7 +21,7 @@ RUN apt-get --allow-unauthenticated update -y \
 # Special dpkg-deb (https://github.com/ClickHouse-Extras/dpkg) version which is able
 # to compress files using pigz (https://zlib.net/pigz/) instead of gzip.
 # Significantly increase deb packaging speed and compatible with old systems
-RUN curl -O https://clickhouse-builds.s3.yandex.net/utils/dpkg-deb
+RUN curl -O https://clickhouse-builds.s3.yandex.net/utils/1/dpkg-deb
 RUN chmod +x dpkg-deb
 RUN cp dpkg-deb /usr/bin

--- a/docker/server/Dockerfile
+++ b/docker/server/Dockerfile
@ -1,7 +1,7 @@
 FROM ubuntu:20.04

 ARG repository="deb https://repo.clickhouse.tech/deb/stable/ main/"
-ARG version=20.7.1.*
+ARG version=20.8.1.*
 ARG gosu_ver=1.10

 RUN apt-get update \
--- a/docker/test/Dockerfile
+++ b/docker/test/Dockerfile
@ -1,7 +1,7 @@
 FROM ubuntu:18.04

 ARG repository="deb https://repo.clickhouse.tech/deb/stable/ main/"
-ARG version=20.7.1.*
+ARG version=20.8.1.*

 RUN apt-get update && \
    apt-get install -y apt-transport-https dirmngr && \
--- a/docker/test/fasttest/run.sh
+++ b/docker/test/fasttest/run.sh
@ -53,7 +53,7 @@ mkdir -p /etc/clickhouse-server
 mkdir -p /etc/clickhouse-client
 mkdir -p /etc/clickhouse-server/config.d
 mkdir -p /etc/clickhouse-server/users.d
-mkdir -p /var/log/clickhouse-server
+ln -s /test_output /var/log/clickhouse-server
 cp $CLICKHOUSE_DIR/programs/server/config.xml /etc/clickhouse-server/
 cp $CLICKHOUSE_DIR/programs/server/users.xml /etc/clickhouse-server/

@ -66,7 +66,6 @@ ln -s /usr/share/clickhouse-test/config/listen.xml /etc/clickhouse-server/config
 ln -s /usr/share/clickhouse-test/config/part_log.xml /etc/clickhouse-server/config.d/
 ln -s /usr/share/clickhouse-test/config/text_log.xml /etc/clickhouse-server/config.d/
 ln -s /usr/share/clickhouse-test/config/metric_log.xml /etc/clickhouse-server/config.d/
-ln -s /usr/share/clickhouse-test/config/query_masking_rules.xml /etc/clickhouse-server/config.d/
 ln -s /usr/share/clickhouse-test/config/custom_settings_prefixes.xml /etc/clickhouse-server/config.d/
 ln -s /usr/share/clickhouse-test/config/log_queries.xml /etc/clickhouse-server/users.d/
 ln -s /usr/share/clickhouse-test/config/readonly.xml /etc/clickhouse-server/users.d/
@ -84,6 +83,10 @@ ln -s /usr/share/clickhouse-test/config/server.crt /etc/clickhouse-server/
 ln -s /usr/share/clickhouse-test/config/dhparam.pem /etc/clickhouse-server/
 ln -sf /usr/share/clickhouse-test/config/client_config.xml /etc/clickhouse-client/config.xml

+# Keep original query_masking_rules.xml
+ln -s --backup=simple --suffix=_original.xml /usr/share/clickhouse-test/config/query_masking_rules.xml /etc/clickhouse-server/config.d/
+
+
 clickhouse-server --config /etc/clickhouse-server/config.xml --daemon

 counter=0
@ -161,15 +164,15 @@ clickhouse-test -j 4 --no-long --testname --shard --zookeeper --skip ${TESTS_TO_


 kill_clickhouse () {
-    kill `ps ax | grep clickhouse-server | grep -v 'grep' | awk '{print $1}'` 2>/dev/null
+    killall clickhouse-server ||:

    for i in {1..10}
    do
-        if ! kill -0 `ps ax | grep clickhouse-server | grep -v 'grep' | awk '{print $1}'`; then
+        if ! killall -0 clickhouse-server; then
            echo "No clickhouse process"
            break
        else
-            echo "Process" `ps ax | grep clickhouse-server | grep -v 'grep' | awk '{print $1}'` "still alive"
+            echo "Clickhouse server process" $(pgrep -f clickhouse-server) "still alive"
            sleep 10
        fi
    done
@ -202,5 +205,3 @@ if [[ ! -z "$FAILED_TESTS" ]]; then
 else
    echo "No failed tests"
 fi
-
-mv /var/log/clickhouse-server/* /test_output
--- a/docker/test/performance-comparison/compare.sh
+++ b/docker/test/performance-comparison/compare.sh
@ -514,14 +514,18 @@ create table queries engine File(TSVWithNamesAndTypes, 'report/queries.tsv')
    ;

 create table changed_perf_report engine File(TSV, 'report/changed-perf.tsv') as
-    select
-        toDecimal64(left, 3), toDecimal64(right, 3),
+    with
        -- server_time is sometimes reported as zero (if it's less than 1 ms),
        -- so we have to work around this to not get an error about conversion
        -- of NaN to decimal.
-        left > right
-            ? '- ' || toString(toDecimal64(left / (right + 0.001), 3)) || 'x'
-            : '+ ' || toString(toDecimal64(right / (left + 0.001), 3)) || 'x',
+        (left > right ? left / right : right / left) as times_change_float,
+        isFinite(times_change_float) as times_change_finite,
+        toDecimal64(times_change_finite ? times_change_float : 1., 3) as times_change_decimal,
+        times_change_finite
+            ? (left > right ? '-' : '+') || toString(times_change_decimal) || 'x'
+            : '--' as times_change_str
+    select
+        toDecimal64(left, 3), toDecimal64(right, 3), times_change_str,
        toDecimal64(diff, 3), toDecimal64(stat_threshold, 3),
        changed_fail, test, query_index, query_display_name
    from queries where changed_show order by abs(diff) desc;
@ -603,11 +607,18 @@ create table test_times_report engine File(TSV, 'report/test-times.tsv') as

 -- report for all queries page, only main metric
 create table all_tests_report engine File(TSV, 'report/all-queries.tsv') as
+    with
+        -- server_time is sometimes reported as zero (if it's less than 1 ms),
+        -- so we have to work around this to not get an error about conversion
+        -- of NaN to decimal.
+        (left > right ? left / right : right / left) as times_change_float,
+        isFinite(times_change_float) as times_change_finite,
+        toDecimal64(times_change_finite ? times_change_float : 1., 3) as times_change_decimal,
+        times_change_finite
+            ? (left > right ? '-' : '+') || toString(times_change_decimal) || 'x'
+            : '--' as times_change_str
    select changed_fail, unstable_fail,
-        toDecimal64(left, 3), toDecimal64(right, 3),
-        left > right
-            ? '- ' || toString(toDecimal64(left / (right + 0.001), 3)) || 'x'
-            : '+ ' || toString(toDecimal64(right / (left + 0.001), 3)) || 'x',
+        toDecimal64(left, 3), toDecimal64(right, 3), times_change_str,
        toDecimal64(isFinite(diff) ? diff : 0, 3),
        toDecimal64(isFinite(stat_threshold) ? stat_threshold : 0, 3),
        test, query_index, query_display_name
--- a/docker/test/performance-comparison/entrypoint.sh
+++ b/docker/test/performance-comparison/entrypoint.sh
@ -14,7 +14,7 @@ function find_reference_sha
    # master, the merge base is the tested commit itself, so we have to step back
    # once.
    start_ref=$(git -C right/ch merge-base origin/master pr)
-    if [ "PR_TO_TEST" == "0" ]
+    if [ "$PR_TO_TEST" == "0" ]
    then
        start_ref=$start_ref~
    fi
--- a/docker/test/performance-comparison/report.py
+++ b/docker/test/performance-comparison/report.py
@ -17,6 +17,8 @@ parser.add_argument('--report', default='main', choices=['main', 'all-queries'],
    help='Which report to build')
 args = parser.parse_args()

+tables = []
+errors_explained = []
 report_errors = []
 error_tests = 0
 slow_average_tests = 0
@ -145,21 +147,42 @@ tr:nth-child(odd) td {{filter: brightness(90%);}}
 table_anchor = 0
 row_anchor = 0

-def nextTableAnchor():
+def currentTableAnchor():
+    global table_anchor
+    return f'{table_anchor}'
+
+def newTableAnchor():
    global table_anchor
    table_anchor += 1
-    return str(table_anchor)
+    return currentTableAnchor()
+
+def currentRowAnchor():
+    global row_anchor
+    global table_anchor
+    return f'{table_anchor}.{row_anchor}'

 def nextRowAnchor():
    global row_anchor
    global table_anchor
-    row_anchor += 1
-    return str(table_anchor) + "." + str(row_anchor)
+    return f'{table_anchor}.{row_anchor + 1}'

-def tr(x):
-    a = nextRowAnchor()
+def setRowAnchor(anchor_row_part):
+    global row_anchor
+    global table_anchor
+    row_anchor = anchor_row_part
+    return currentRowAnchor()
+
+def advanceRowAnchor():
+    global row_anchor
+    global table_anchor
+    row_anchor += 1
+    return currentRowAnchor()
+
+
+def tr(x, anchor=None):
    #return '<tr onclick="location.href=\'#{a}\'" id={a}>{x}</tr>'.format(a=a, x=str(x))
-    return '<tr id={a}>{x}</tr>'.format(a=a, x=str(x))
+    anchor = anchor if anchor else advanceRowAnchor()
+    return f'<tr id={anchor}>{x}</tr>'

 def td(value, cell_attributes = ''):
    return '<td {cell_attributes}>{value}</td>'.format(
@ -169,19 +192,23 @@ def td(value, cell_attributes = ''):
 def th(x):
    return '<th>' + str(x) + '</th>'

-def tableRow(cell_values, cell_attributes = []):
-    return tr(''.join([td(v, a)
+def tableRow(cell_values, cell_attributes = [], anchor=None):
+    return tr(
+        ''.join([td(v, a)
            for v, a in itertools.zip_longest(
                cell_values, cell_attributes,
                fillvalue = '')
-        if a is not None and v is not None]))
+            if a is not None and v is not None]),
+        anchor)

 def tableHeader(r):
    return tr(''.join([th(f) for f in r]))

 def tableStart(title):
-    anchor = nextTableAnchor();
    cls = '-'.join(title.lower().split(' ')[:3]);
+    global table_anchor
+    table_anchor = cls
+    anchor = currentTableAnchor()
    return f"""
        <h2 id="{anchor}">
            <a class="cancela" href="#{anchor}">{title}</a>
@ -211,20 +238,23 @@ def htmlRows(n):
        result += tableRow(row)
    return result

-def printSimpleTable(caption, columns, rows):
+def addSimpleTable(caption, columns, rows, pos=None):
+    global tables
+    text = ''
    if not rows:
        return

-    print(tableStart(caption))
-    print(tableHeader(columns))
+    text += tableStart(caption)
+    text += tableHeader(columns)
    for row in rows:
-        print(tableRow(row))
-    print(tableEnd())
+        text += tableRow(row)
+    text += tableEnd()
+    tables.insert(pos if pos else len(tables), text)

-def print_tested_commits():
+def add_tested_commits():
    global report_errors
    try:
-        printSimpleTable('Tested commits', ['Old', 'New'],
+        addSimpleTable('Tested commits', ['Old', 'New'],
            [['<pre>{}</pre>'.format(x) for x in
                [open('left-commit.txt').read(),
                 open('right-commit.txt').read()]]])
@ -235,7 +265,8 @@ def print_tested_commits():
                *sys.exc_info()[:2])[-1])
        pass

-def print_report_errors():
+def add_report_errors():
+    global tables
    global report_errors
    # Add the errors reported by various steps of comparison script
    try:
@ -246,67 +277,100 @@ def print_report_errors():
                *sys.exc_info()[:2])[-1])
        pass

-    if len(report_errors):
-        print(tableStart('Errors while building the report'))
-        print(tableHeader(['Error']))
+    if not report_errors:
+        return
+
+    text = tableStart('Errors while building the report')
+    text += tableHeader(['Error'])
    for x in report_errors:
-            print(tableRow([x]))
-        print(tableEnd())
+        text += tableRow([x])
+    text += tableEnd()
+    # Insert after Tested Commits
+    tables.insert(1, text)
+    errors_explained.append([f'<a href="#{currentTableAnchor()}">There were some errors while building the report</a>']);
+
+def add_errors_explained():
+    if not errors_explained:
+        return
+
+    text = '<a name="fail1"/>'
+    text += tableStart('Error summary')
+    text += tableHeader(['Description'])
+    for row in errors_explained:
+        text += tableRow(row)
+    text += tableEnd()
+
+    global tables
+    tables.insert(1, text)
+

 if args.report == 'main':
    print(header_template.format())

-    print_tested_commits()
+    add_tested_commits()
+

    run_error_rows = tsvRows('run-errors.tsv')
    error_tests += len(run_error_rows)
-    printSimpleTable('Run errors', ['Test', 'Error'], run_error_rows)
+    addSimpleTable('Run errors', ['Test', 'Error'], run_error_rows)
+    if run_error_rows:
+        errors_explained.append([f'<a href="#{currentTableAnchor()}">There were some errors while running the tests</a>']);
+

    slow_on_client_rows = tsvRows('report/slow-on-client.tsv')
    error_tests += len(slow_on_client_rows)
-    printSimpleTable('Slow on client',
+    addSimpleTable('Slow on client',
                     ['Client time,&nbsp;s', 'Server time,&nbsp;s', 'Ratio', 'Test', 'Query'],
                     slow_on_client_rows)
+    if slow_on_client_rows:
+        errors_explained.append([f'<a href="#{currentTableAnchor()}">Some queries are taking noticeable time client-side (missing `FORMAT Null`?)</a>']);

    unmarked_short_rows = tsvRows('report/unmarked-short-queries.tsv')
    error_tests += len(unmarked_short_rows)
-    printSimpleTable('Short queries not marked as short',
+    addSimpleTable('Short queries not marked as short',
        ['New client time, s', 'Test', '#', 'Query'],
        unmarked_short_rows)
+    if unmarked_short_rows:
+        errors_explained.append([f'<a href="#{currentTableAnchor()}">Some queries have short duration but are not explicitly marked as "short"</a>']);

-    def print_partial():
+    def add_partial():
        rows = tsvRows('report/partial-queries-report.tsv')
        if not rows:
            return
-        global unstable_partial_queries, slow_average_tests
-        print(tableStart('Partial queries'))
+
+        global unstable_partial_queries, slow_average_tests, tables
+        text = tableStart('Partial queries')
        columns = ['Median time, s', 'Relative time variance', 'Test', '#', 'Query']
-        print(tableHeader(columns))
+        text += tableHeader(columns)
        attrs = ['' for c in columns]
        for row in rows:
+            anchor = f'{currentTableAnchor()}.{row[2]}.{row[3]}'
            if float(row[1]) > 0.10:
                attrs[1] = f'style="background: {color_bad}"'
                unstable_partial_queries += 1
+                errors_explained.append([f'<a href="#{anchor}">The query no. {row[3]} of test \'{row[2]}\' has excessive variance of run time. Keep it below 10%</a>'])
            else:
                attrs[1] = ''
            if float(row[0]) > allowed_single_run_time:
                attrs[0] = f'style="background: {color_bad}"'
+                errors_explained.append([f'<a href="#{anchor}">The query no. {row[3]} of test \'{row[2]}\' is taking too long to run. Keep the run time below {allowed_single_run} seconds"</a>'])
                slow_average_tests += 1
            else:
                attrs[0] = ''
-            print(tableRow(row, attrs))
-        print(tableEnd())
+            text += tableRow(row, attrs, anchor)
+        text += tableEnd()
+        tables.append(text)

-    print_partial()
+    add_partial()

-    def print_changes():
+    def add_changes():
        rows = tsvRows('report/changed-perf.tsv')
        if not rows:
            return

-        global faster_queries, slower_queries
+        global faster_queries, slower_queries, tables

-        print(tableStart('Changes in performance'))
+        text = tableStart('Changes in performance')
        columns = [
            'Old,&nbsp;s',                                          # 0
            'New,&nbsp;s',                                          # 1
@ -319,11 +383,12 @@ if args.report == 'main':
            'Query',                                           # 8
            ]

-        print(tableHeader(columns))
+        text += tableHeader(columns)

        attrs = ['' for c in columns]
        attrs[5] = None
        for row in rows:
+            anchor = f'{currentTableAnchor()}.{row[6]}.{row[7]}'
            if int(row[5]):
                if float(row[3]) < 0.:
                    faster_queries += 1
@ -331,18 +396,19 @@ if args.report == 'main':
                else:
                    slower_queries += 1
                    attrs[2] = attrs[3] = f'style="background: {color_bad}"'
+                    errors_explained.append([f'<a href="#{anchor}">The query no. {row[7]} of test \'{row[6]}\' has slowed down</a>'])
            else:
                attrs[2] = attrs[3] = ''

-            print(tableRow(row, attrs))
+            text += tableRow(row, attrs, anchor)

-        print(tableEnd())
+        text += tableEnd()
+        tables.append(text)

-    print_changes()
+    add_changes()

-    def print_unstable_queries():
-        global unstable_queries
-        global very_unstable_queries
+    def add_unstable_queries():
+        global unstable_queries, very_unstable_queries, tables

        unstable_rows = tsvRows('report/unstable-queries.tsv')
        if not unstable_rows:
@ -361,33 +427,35 @@ if args.report == 'main':
            'Query' #7
        ]

-        print(tableStart('Unstable queries'))
-        print(tableHeader(columns))
+        text = tableStart('Unstable queries')
+        text += tableHeader(columns)

        attrs = ['' for c in columns]
        attrs[4] = None
        for r in unstable_rows:
+            anchor = f'{currentTableAnchor()}.{r[5]}.{r[6]}'
            if int(r[4]):
                very_unstable_queries += 1
                attrs[3] = f'style="background: {color_bad}"'
            else:
                attrs[3] = ''

-            print(tableRow(r, attrs))
+            text += tableRow(r, attrs, anchor)

-        print(tableEnd())
+        text += tableEnd()
+        tables.append(text)

-    print_unstable_queries()
+    add_unstable_queries()

    skipped_tests_rows = tsvRows('analyze/skipped-tests.tsv')
-    printSimpleTable('Skipped tests', ['Test', 'Reason'], skipped_tests_rows)
+    addSimpleTable('Skipped tests', ['Test', 'Reason'], skipped_tests_rows)

-    printSimpleTable('Test performance changes',
+    addSimpleTable('Test performance changes',
        ['Test', 'Queries', 'Unstable', 'Changed perf', 'Total not OK', 'Avg relative time diff'],
        tsvRows('report/test-perf-changes.tsv'))

-    def print_test_times():
-        global slow_average_tests
+    def add_test_times():
+        global slow_average_tests, tables
        rows = tsvRows('report/test-times.tsv')
        if not rows:
            return
@ -403,8 +471,8 @@ if args.report == 'main':
            'Shortest query<br>(sum for all runs),&nbsp;s',       #7
            ]

-        print(tableStart('Test times'))
-        print(tableHeader(columns))
+        text = tableStart('Test times')
+        text += tableHeader(columns)

        nominal_runs = 13  # FIXME pass this as an argument
        total_runs = (nominal_runs + 1) * 2  # one prewarm run, two servers
@ -414,22 +482,25 @@ if args.report == 'main':
                # FIXME should be 15s max -- investigate parallel_insert
                slow_average_tests += 1
                attrs[6] = f'style="background: {color_bad}"'
+                errors_explained.append([f'<a href="./all-queries.html#all-query-times.{r[0]}.0">The test \'{r[0]}\' is too slow to run as a whole. Investigate whether the create and fill queries can be sped up'])
            else:
                attrs[6] = ''

            if float(r[5]) > allowed_single_run_time * total_runs:
                slow_average_tests += 1
                attrs[5] = f'style="background: {color_bad}"'
+                errors_explained.append([f'<a href="./all-queries.html#all-query-times.{r[0]}.0">Some query of the test \'{r[0]}\' is too slow to run. See the all queries report'])
            else:
                attrs[5] = ''

-            print(tableRow(r, attrs))
+            text += tableRow(r, attrs)

-        print(tableEnd())
+        text += tableEnd()
+        tables.append(text)

-    print_test_times()
+    add_test_times()

-    def print_benchmark_results():
+    def add_benchmark_results():
        if not os.path.isfile('benchmark/website-left.json'):
            return

@ -479,26 +550,33 @@ if args.report == 'main':

            all_rows.append([row, attrs])

-        print(tableStart('Concurrent benchmarks'))
-        print(tableHeader(header))
+        text = tableStart('Concurrent benchmarks')
+        text += tableHeader(header)
        for row, attrs in all_rows:
-            print(tableRow(row, attrs))
-        print(tableEnd())
+            text += tableRow(row, attrs)
+        text += tableEnd()
+
+        global tables
+        tables.append(text)

    try:
-        print_benchmark_results()
+        add_benchmark_results()
    except:
        report_errors.append(
            traceback.format_exception_only(
                *sys.exc_info()[:2])[-1])
        pass

-    printSimpleTable('Metric changes',
+    addSimpleTable('Metric changes',
        ['Metric', 'Old median value', 'New median value',
            'Relative difference', 'Times difference'],
        tsvRows('metrics/changes.tsv'))

-    print_report_errors()
+    add_report_errors()
+    add_errors_explained()
+
+    for t in tables:
+        print(t)

    print("""
    <p class="links">
@ -559,9 +637,9 @@ elif args.report == 'all-queries':

    print(header_template.format())

-    print_tested_commits()
+    add_tested_commits()

-    def print_all_queries():
+    def add_all_queries():
        rows = tsvRows('report/all-queries.tsv')
        if not rows:
            return
@ -579,13 +657,14 @@ elif args.report == 'all-queries':
            'Query',                                  #9
            ]

-        print(tableStart('All query times'))
-        print(tableHeader(columns))
+        text = tableStart('All query times')
+        text += tableHeader(columns)

        attrs = ['' for c in columns]
        attrs[0] = None
        attrs[1] = None
        for r in rows:
+            anchor = f'{currentTableAnchor()}.{r[7]}.{r[8]}'
            if int(r[1]):
                attrs[6] = f'style="background: {color_bad}"'
            else:
@ -606,13 +685,15 @@ elif args.report == 'all-queries':
                attrs[2] = ''
                attrs[3] = ''

-            print(tableRow(r, attrs))
+            text += tableRow(r, attrs, anchor)

-        print(tableEnd())
+        text += tableEnd()
+        tables.append(text)

-    print_all_queries()
-
-    print_report_errors()
+    add_all_queries()
+    add_report_errors()
+    for t in tables:
+        print(t)

    print("""
    <p class="links">
--- a/docs/en/getting-started/install.md
+++ b/docs/en/getting-started/install.md
@ -166,7 +166,7 @@ For more information, see the section [“Command-line client”](../interfaces/

 Example:

-``` bash
+```
 $ ./clickhouse-client
 ClickHouse client version 0.0.18749.
 Connecting to localhost:9000.
--- a/docs/en/getting-started/playground.md
+++ b/docs/en/getting-started/playground.md
@ -48,13 +48,13 @@ The following settings are also enforced:
 HTTPS endpoint example with `curl`:

 ``` bash
-curl "https://play-api.clickhouse.tech:8443/?query=SELECT+'Play+ClickHouse!';&user=playground&password=clickhouse&database=datasets"
+curl "https://play-api.clickhouse.tech:8443/?query=SELECT+'Play+ClickHouse\!';&user=playground&password=clickhouse&database=datasets"
 ```

 TCP endpoint example with [CLI](../interfaces/cli.md):

 ``` bash
-clickhouse client --secure -h play-api.clickhouse.tech --port 9440 -u playground --password clickhouse -q "SELECT 'Play ClickHouse!'"
+clickhouse client --secure -h play-api.clickhouse.tech --port 9440 -u playground --password clickhouse -q "SELECT 'Play ClickHouse\!'"
 ```

 ## Implementation Details {#implementation-details}
--- a/docs/en/interfaces/third-party/gui.md
+++ b/docs/en/interfaces/third-party/gui.md
@ -65,6 +65,14 @@ Features:
 -   Database explorer.
 -   Visualization tools, that allow you to represent data in different forms.

+### Grafana {#grafana}
+
+[Grafana](https://grafana.com/grafana/plugins/vertamedia-clickhouse-datasource) is a platform for monitoring and visualization.
+
+"Grafana allows you to query, visualize, alert on and understand your metrics no matter where they are stored. Create, explore, and share dashboards with your team and foster a data driven culture. Trusted and loved by the community" &mdash; grafana.com.
+
+ClickHouse datasource plugin provides a support for ClickHouse as a backend database.
+
 ### DBeaver {#dbeaver}

 [DBeaver](https://dbeaver.io/) - universal desktop database client with ClickHouse support.
--- a/docs/en/operations/system-tables/asynchronous_metric_log.md
+++ b/docs/en/operations/system-tables/asynchronous_metric_log.md
@ -1,4 +1,4 @@
-## system.asynchronous\_metric\_log {#system-tables-async-log}
+## system.asynchronous_metric_log {#system-tables-async-log}

 Contains the historical values for `system.asynchronous_metrics`, which are saved once per minute. This feature is enabled by default.

@ -32,5 +32,7 @@ SELECT * FROM system.asynchronous_metric_log LIMIT 10

 **See Also**

- [system.asynchronous\_metrics](../system-tables/asynchronous_metrics.md) — Contains metrics that are calculated periodically in the background. 
+- [system.asynchronous_metrics](../system-tables/asynchronous_metrics.md) — Contains metrics that are calculated periodically in the background. 
 - [system.metric_log](../system-tables/metric_log.md) — Contains history of metrics values from tables `system.metrics` and `system.events`, periodically flushed to disk.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/asynchronous_metric_log) <!--hide-->
--- a/docs/en/operations/system-tables/asynchronous_metrics.md
+++ b/docs/en/operations/system-tables/asynchronous_metrics.md
@ -34,3 +34,5 @@ SELECT * FROM system.asynchronous_metrics LIMIT 10
 -   [system.metrics](../../operations/system-tables/metrics.md#system_tables-metrics) — Contains instantly calculated metrics.
 -   [system.events](../../operations/system-tables/events.md#system_tables-events) — Contains a number of events that have occurred.
 -   [system.metric\_log](../../operations/system-tables/metric_log.md#system_tables-metric_log) — Contains a history of metrics values from tables `system.metrics` и `system.events`.
+
+ [Original article](https://clickhouse.tech/docs/en/operations/system_tables/asynchronous_metrics) <!--hide-->
--- a/docs/en/operations/system-tables/clusters.md
+++ b/docs/en/operations/system-tables/clusters.md
@ -22,3 +22,5 @@ Please note that `errors_count` is updated once per query to the cluster, but `e
 -   [Table engine Distributed](../../engines/table-engines/special/distributed.md)
 -   [distributed\_replica\_error\_cap setting](../../operations/settings/settings.md#settings-distributed_replica_error_cap)
 -   [distributed\_replica\_error\_half\_life setting](../../operations/settings/settings.md#settings-distributed_replica_error_half_life)
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/clusters) <!--hide-->
--- a/docs/en/operations/system-tables/columns.md
+++ b/docs/en/operations/system-tables/columns.md
@ -20,3 +20,5 @@ The `system.columns` table contains the following columns (the column type is sh
 -   `is_in_sorting_key` (UInt8) — Flag that indicates whether the column is in the sorting key expression.
 -   `is_in_primary_key` (UInt8) — Flag that indicates whether the column is in the primary key expression.
 -   `is_in_sampling_key` (UInt8) — Flag that indicates whether the column is in the sampling key expression.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/columns) <!--hide-->
--- a/docs/en/operations/system-tables/contributors.md
+++ b/docs/en/operations/system-tables/contributors.md
@ -38,3 +38,4 @@ SELECT * FROM system.contributors WHERE name = 'Olga Khvostikova'
 │ Olga Khvostikova │
 └──────────────────┘
 ```
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/contributors) <!--hide-->
--- a/docs/en/operations/system-tables/current-roles.md
+++ b/docs/en/operations/system-tables/current-roles.md
@ -1,4 +1,5 @@
 # system.current_roles {#system_tables-current_roles}
+
 Contains active roles of a current user. `SET ROLE` changes the contents of this table.

 Columns:
--- a/docs/en/operations/system-tables/data_type_families.md
+++ b/docs/en/operations/system-tables/data_type_families.md
@ -1,4 +1,4 @@
-# system.data\_type\_families {#system_tables-data_type_families}
+# system.data_type_families {#system_tables-data_type_families}

 Contains information about supported [data types](../../sql-reference/data-types/).

@ -32,3 +32,5 @@ SELECT * FROM system.data_type_families WHERE alias_to = 'String'
 **See Also**

 -   [Syntax](../../sql-reference/syntax.md) — Information about supported syntax.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/data_type_families) <!--hide-->
--- a/docs/en/operations/system-tables/databases.md
+++ b/docs/en/operations/system-tables/databases.md
@ -5,3 +5,5 @@ This table contains a single String column called ‘name’ – the name of a d
 Each database that the server knows about has a corresponding entry in the table.

 This system table is used for implementing the `SHOW DATABASES` query.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/databases) <!--hide-->
--- a/docs/en/operations/system-tables/detached_parts.md
+++ b/docs/en/operations/system-tables/detached_parts.md
@ -1,4 +1,4 @@
-# system.detached\_parts {#system_tables-detached_parts}
+# system.detached_parts {#system_tables-detached_parts}

 Contains information about detached parts of [MergeTree](../../engines/table-engines/mergetree-family/mergetree.md) tables. The `reason` column specifies why the part was detached.

@ -7,3 +7,5 @@ For user-detached parts, the reason is empty. Such parts can be attached with [A
 For the description of other columns, see [system.parts](../../operations/system-tables/parts.md#system_tables-parts).

 If part name is invalid, values of some columns may be `NULL`. Such parts can be deleted with [ALTER TABLE DROP DETACHED PART](../../sql-reference/statements/alter/partition.md#alter_drop-detached).
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/detached_parts) <!--hide-->
--- a/docs/en/operations/system-tables/dictionaries.md
+++ b/docs/en/operations/system-tables/dictionaries.md
@ -59,3 +59,5 @@ SELECT * FROM system.dictionaries
 │ dictdb   │ dict │ LOADED │ dictdb.dict │ Flat │ UInt64 │ ['value_default','value_expression'] │ ['String','String'] │           74032 │           0 │        1 │             1 │ 0.0004887585532746823 │ ClickHouse: dictdb.dicttbl │            0 │            1 │ 2020-03-04 04:17:34 │   2020-03-04 04:30:34        │                 0.002 │                │
 └──────────┴──────┴────────┴─────────────┴──────┴────────┴──────────────────────────────────────┴─────────────────────┴─────────────────┴─────────────┴──────────┴───────────────┴───────────────────────┴────────────────────────────┴──────────────┴──────────────┴─────────────────────┴──────────────────────────────┘───────────────────────┴────────────────┘
 ```
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/dictionaries) <!--hide-->
--- a/docs/en/operations/system-tables/disks.md
+++ b/docs/en/operations/system-tables/disks.md
@ -10,17 +10,4 @@ Columns:
 -   `total_space` ([UInt64](../../sql-reference/data-types/int-uint.md)) — Disk volume in bytes.
 -   `keep_free_space` ([UInt64](../../sql-reference/data-types/int-uint.md)) — Amount of disk space that should stay free on disk in bytes. Defined in the `keep_free_space_bytes` parameter of disk configuration.

-## system.storage\_policies {#system_tables-storage_policies}
-
-Contains information about storage policies and volumes defined in the [server configuration](../../engines/table-engines/mergetree-family/mergetree.md#table_engine-mergetree-multiple-volumes_configure).
-
-Columns:
-
-   `policy_name` ([String](../../sql-reference/data-types/string.md)) — Name of the storage policy.
-   `volume_name` ([String](../../sql-reference/data-types/string.md)) — Volume name defined in the storage policy.
-   `volume_priority` ([UInt64](../../sql-reference/data-types/int-uint.md)) — Volume order number in the configuration.
-   `disks` ([Array(String)](../../sql-reference/data-types/array.md)) — Disk names, defined in the storage policy.
-   `max_data_part_size` ([UInt64](../../sql-reference/data-types/int-uint.md)) — Maximum size of a data part that can be stored on volume disks (0 — no limit).
-   `move_factor` ([Float64](../../sql-reference/data-types/float.md)) — Ratio of free disk space. When the ratio exceeds the value of configuration parameter, ClickHouse start to move data to the next volume in order.
-
-If the storage policy contains more then one volume, then information for each volume is stored in the individual row of the table.
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/disks) <!--hide-->
--- a/docs/en/operations/system-tables/enabled-roles.md
+++ b/docs/en/operations/system-tables/enabled-roles.md
@ -1,4 +1,5 @@
 # system.enabled_roles {#system_tables-enabled_roles}
+
 Contains all active roles at the moment, including current role of the current user and granted roles for current role. 

 Columns:
--- a/docs/en/operations/system-tables/events.md
+++ b/docs/en/operations/system-tables/events.md
@ -30,3 +30,5 @@ SELECT * FROM system.events LIMIT 5
 -   [system.metrics](../../operations/system-tables/metrics.md#system_tables-metrics) — Contains instantly calculated metrics.
 -   [system.metric\_log](../../operations/system-tables/metric_log.md#system_tables-metric_log) — Contains a history of metrics values from tables `system.metrics` и `system.events`.
 -   [Monitoring](../../operations/monitoring.md) — Base concepts of ClickHouse monitoring.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/events) <!--hide-->
--- a/docs/en/operations/system-tables/functions.md
+++ b/docs/en/operations/system-tables/functions.md
@ -6,3 +6,5 @@ Columns:

 -   `name`(`String`) – The name of the function.
 -   `is_aggregate`(`UInt8`) — Whether the function is aggregate.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/functions) <!--hide-->
--- a/docs/en/operations/system-tables/graphite_retentions.md
+++ b/docs/en/operations/system-tables/graphite_retentions.md
@ -1,4 +1,4 @@
-# system.graphite\_retentions {#system-graphite-retentions}
+# system.graphite_retentions {#system-graphite-retentions}

 Contains information about parameters [graphite\_rollup](../../operations/server-configuration-parameters/settings.md#server_configuration_parameters-graphite) which are used in tables with [\*GraphiteMergeTree](../../engines/table-engines/mergetree-family/graphitemergetree.md) engines.

@ -13,3 +13,5 @@ Columns:
 -   `is_default` (UInt8) - Whether the pattern is the default.
 -   `Tables.database` (Array(String)) - Array of names of database tables that use the `config_name` parameter.
 -   `Tables.table` (Array(String)) - Array of table names that use the `config_name` parameter.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/graphite_retentions) <!--hide-->
--- a/docs/en/operations/system-tables/merge_tree_settings.md
+++ b/docs/en/operations/system-tables/merge_tree_settings.md
@ -1,4 +1,4 @@
-# system.merge\_tree\_settings {#system-merge_tree_settings}
+# system.merge_tree_settings {#system-merge_tree_settings}

 Contains information about settings for `MergeTree` tables.

@ -9,3 +9,5 @@ Columns:
 -   `description` (String) — Setting description.
 -   `type` (String) — Setting type (implementation specific string value).
 -   `changed` (UInt8) — Whether the setting was explicitly defined in the config or explicitly changed.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/merge_tree_settings) <!--hide-->
--- a/docs/en/operations/system-tables/merges.md
+++ b/docs/en/operations/system-tables/merges.md
@ -17,3 +17,5 @@ Columns:
 -   `rows_read` (UInt64) — Number of rows read.
 -   `bytes_written_uncompressed` (UInt64) — Number of bytes written, uncompressed.
 -   `rows_written` (UInt64) — Number of rows written.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/merges) <!--hide-->
--- a/docs/en/operations/system-tables/metric_log.md
+++ b/docs/en/operations/system-tables/metric_log.md
@ -1,4 +1,4 @@
-# system.metric\_log {#system_tables-metric_log}
+# system.metric_log {#system_tables-metric_log}

 Contains history of metrics values from tables `system.metrics` and `system.events`, periodically flushed to disk.
 To turn on metrics history collection on `system.metric_log`, create `/etc/clickhouse-server/config.d/metric_log.xml` with following content:
@ -53,3 +53,5 @@ CurrentMetric_ReplicatedChecks:                             0
 -   [system.events](../../operations/system-tables/events.md#system_tables-events) — Contains a number of events that occurred.
 -   [system.metrics](../../operations/system-tables/metrics.md) — Contains instantly calculated metrics.
 -   [Monitoring](../../operations/monitoring.md) — Base concepts of ClickHouse monitoring.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/metric_log) <!--hide-->
--- a/docs/en/operations/system-tables/metrics.md
+++ b/docs/en/operations/system-tables/metrics.md
@ -37,3 +37,5 @@ SELECT * FROM system.metrics LIMIT 10
 -   [system.events](../../operations/system-tables/events.md#system_tables-events) — Contains a number of events that occurred.
 -   [system.metric\_log](../../operations/system-tables/metric_log.md#system_tables-metric_log) — Contains a history of metrics values from tables `system.metrics` и `system.events`.
 -   [Monitoring](../../operations/monitoring.md) — Base concepts of ClickHouse monitoring.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/metrics) <!--hide-->
--- a/docs/en/operations/system-tables/mutations.md
+++ b/docs/en/operations/system-tables/mutations.md
@ -44,3 +44,5 @@ If there were problems with mutating some data parts, the following columns cont
 -   [Mutations](../../sql-reference/statements/alter/index.md#mutations)
 -   [MergeTree](../../engines/table-engines/mergetree-family/mergetree.md) table engine
 -   [ReplicatedMergeTree](../../engines/table-engines/mergetree-family/replication.md) family
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/mutations) <!--hide-->
--- a/docs/en/operations/system-tables/numbers.md
+++ b/docs/en/operations/system-tables/numbers.md
@ -5,3 +5,5 @@ This table contains a single UInt64 column named `number` that contains almost a
 You can use this table for tests, or if you need to do a brute force search.

 Reads from this table are not parallelized.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/numbers) <!--hide-->
--- a/docs/en/operations/system-tables/numbers_mt.md
+++ b/docs/en/operations/system-tables/numbers_mt.md
@ -1,5 +1,7 @@
-# system.numbers\_mt {#system-numbers-mt}
+# system.numbers_mt {#system-numbers-mt}

 The same as [system.numbers](../../operations/system-tables/numbers.md) but reads are parallelized. The numbers can be returned in any order.

 Used for tests.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/numbers_mt) <!--hide-->
--- a/docs/en/operations/system-tables/one.md
+++ b/docs/en/operations/system-tables/one.md
@ -5,3 +5,5 @@ This table contains a single row with a single `dummy` UInt8 column containing t
 This table is used if a `SELECT` query doesn’t specify the `FROM` clause.

 This is similar to the `DUAL` table found in other DBMSs.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/one) <!--hide-->
--- a/docs/en/operations/system-tables/part_log.md
+++ b/docs/en/operations/system-tables/part_log.md
@ -1,4 +1,4 @@
-# system.part\_log {#system_tables-part-log}
+# system.part_log {#system_tables-part-log}

 The `system.part_log` table is created only if the [part\_log](../../operations/server-configuration-parameters/settings.md#server_configuration_parameters-part-log) server setting is specified.

@ -30,3 +30,5 @@ The `system.part_log` table contains the following columns:
 -   `exception` (String) — Text message of the occurred error.

 The `system.part_log` table is created after the first inserting data to the `MergeTree` table.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/part_log) <!--hide-->
--- a/docs/en/operations/system-tables/parts.md
+++ b/docs/en/operations/system-tables/parts.md
@ -154,3 +154,5 @@ move_ttl_info.max:                     []

 -   [MergeTree family](../../engines/table-engines/mergetree-family/mergetree.md)
 -   [TTL for Columns and Tables](../../engines/table-engines/mergetree-family/mergetree.md#table_engine-mergetree-ttl)
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/parts) <!--hide-->
--- a/docs/en/operations/system-tables/processes.md
+++ b/docs/en/operations/system-tables/processes.md
@ -13,3 +13,5 @@ Columns:
 -   `memory_usage` (UInt64) – Amount of RAM the request uses. It might not include some types of dedicated memory. See the [max\_memory\_usage](../../operations/settings/query-complexity.md#settings_max_memory_usage) setting.
 -   `query` (String) – The query text. For `INSERT`, it doesn’t include the data to insert.
 -   `query_id` (String) – Query ID, if defined.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/processes) <!--hide-->
--- a/docs/en/operations/system-tables/query_log.md
+++ b/docs/en/operations/system-tables/query_log.md
@ -1,4 +1,4 @@
-# system.query\_log {#system_tables-query_log}
+# system.query_log {#system_tables-query_log}

 Contains information about executed queries, for example, start time, duration of processing, error messages.

@ -136,3 +136,6 @@ Settings.Values:      ['0','random','1','10000000000']
 **See Also**

 -   [system.query\_thread\_log](../../operations/system-tables/query_thread_log.md#system_tables-query_thread_log) — This table contains information about each query execution thread.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/query_log) <!--hide-->
+
--- a/docs/en/operations/system-tables/query_thread_log.md
+++ b/docs/en/operations/system-tables/query_thread_log.md
@ -1,4 +1,4 @@
-# system.query\_thread\_log {#system_tables-query_thread_log}
+# system.query_thread_log {#system_tables-query_thread_log}

 Contains information about threads which execute queries, for example, thread name, thread start time, duration of query processing.

@ -111,3 +111,5 @@ ProfileEvents.Values: [1,97,81,5,81]
 **See Also**

 -   [system.query\_log](../../operations/system-tables/query_log.md#system_tables-query_log) — Description of the `query_log` system table which contains common information about queries execution.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/query_thread_log) <!--hide-->
--- a/docs/en/operations/system-tables/quota_limits.md
+++ b/docs/en/operations/system-tables/quota_limits.md
@ -1,4 +1,4 @@
-# system.quota\_limits {#system_tables-quota_limits}
+# system.quota_limits {#system_tables-quota_limits}

 Contains information about maximums for all intervals of all quotas. Any number of rows or zero can correspond to one quota.

@ -15,3 +15,5 @@ Columns:
 - `max_read_rows` ([Nullable](../../sql-reference/data-types/nullable.md)([UInt64](../../sql-reference/data-types/int-uint.md))) — Maximum number of rows read from all tables and table functions participated in queries.
 - `max_read_bytes` ([Nullable](../../sql-reference/data-types/nullable.md)([UInt64](../../sql-reference/data-types/int-uint.md))) — Maximum number of bytes read from all tables and table functions participated in queries.
 - `max_execution_time` ([Nullable](../../sql-reference/data-types/nullable.md)([Float64](../../sql-reference/data-types/float.md))) — Maximum of the query execution time, in seconds.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/quota_limits) <!--hide-->
--- a/docs/en/operations/system-tables/quota_usage.md
+++ b/docs/en/operations/system-tables/quota_usage.md
@ -1,4 +1,4 @@
-# system.quota\_usage {#system_tables-quota_usage}
+# system.quota_usage {#system_tables-quota_usage}

 Quota usage by the current user: how much is used and how much is left.

@ -22,3 +22,5 @@ Columns:
 - `max_read_bytes` ([Nullable](../../sql-reference/data-types/nullable.md)([UInt64](../../sql-reference/data-types/int-uint.md))) — Maximum of bytes read from all tables and table functions.
 - `execution_time` ([Nullable](../../sql-reference/data-types/nullable.md)([Float64](../../sql-reference/data-types/float.md))) — The total query execution time, in seconds (wall time).
 - `max_execution_time` ([Nullable](../../sql-reference/data-types/nullable.md)([Float64](../../sql-reference/data-types/float.md))) — Maximum of query execution time.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/quota_usage) <!--hide-->
--- a/docs/en/operations/system-tables/quotas.md
+++ b/docs/en/operations/system-tables/quotas.md
@ -19,3 +19,6 @@ Columns:
 - `1` — The quota applies to all users except those listed in `apply_to_except`.
 - `apply_to_list` ([Array](../../sql-reference/data-types/array.md)([String](../../sql-reference/data-types/string.md))) — List of user names/[roles](../../operations/access-rights.md#role-management) that the quota should be applied to.
 - `apply_to_except` ([Array](../../sql-reference/data-types/array.md)([String](../../sql-reference/data-types/string.md))) — List of user names/roles that the quota should not apply to.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/quotas) <!--hide-->
+
--- a/docs/en/operations/system-tables/quotas_usage.md
+++ b/docs/en/operations/system-tables/quotas_usage.md
@ -1,4 +1,4 @@
-# system.quotas\_usage {#system_tables-quotas_usage}
+# system.quotas_usage {#system_tables-quotas_usage}

 Quota usage by all users.

@ -23,3 +23,5 @@ Columns:
 - `max_read_bytes` ([Nullable](../../sql-reference/data-types/nullable.md)([UInt64](../../sql-reference/data-types/int-uint.md))) — Maximum of bytes read from all tables and table functions.
 - `execution_time` ([Nullable](../../sql-reference/data-types/nullable.md)([Float64](../../sql-reference/data-types/float.md))) — The total query execution time, in seconds (wall time).
 - `max_execution_time` ([Nullable](../../sql-reference/data-types/nullable.md)([Float64](../../sql-reference/data-types/float.md))) — Maximum of query execution time.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/quotas_usage) <!--hide-->
--- a/docs/en/operations/system-tables/replicas.md
+++ b/docs/en/operations/system-tables/replicas.md
@ -119,3 +119,6 @@ WHERE
 ```

 If this query doesn’t return anything, it means that everything is fine.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/replicas) <!--hide-->
+
--- a/docs/en/operations/system-tables/role-grants.md
+++ b/docs/en/operations/system-tables/role-grants.md
@ -1,4 +1,5 @@
 #system.role_grants {#system_tables-role_grants}
+
 Contains the role grants for users and roles. To add entries to this table, use `GRANT role TO user`.

 Columns:
--- a/docs/en/operations/system-tables/roles.md
+++ b/docs/en/operations/system-tables/roles.md
@ -1,4 +1,5 @@
 # system.roles {#system_tables-roles}
+
 Contains information about configured [roles](../../operations/access-rights.md#role-management).

 Columns:
--- a/docs/en/operations/system-tables/settings.md
+++ b/docs/en/operations/system-tables/settings.md
@ -48,3 +48,5 @@ SELECT * FROM system.settings WHERE changed AND name='load_balancing'
 -   [Settings](../../operations/settings/index.md#session-settings-intro)
 -   [Permissions for Queries](../../operations/settings/permissions-for-queries.md#settings_readonly)
 -   [Constraints on Settings](../../operations/settings/constraints-on-settings.md)
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/settings) <!--hide-->
--- a/docs/en/operations/system-tables/storage_policies.md
+++ b/docs/en/operations/system-tables/storage_policies.md
@ -1,4 +1,4 @@
-# system.storage\_policies {#system_tables-storage_policies}
+# system.storage_policies {#system_tables-storage_policies}

 Contains information about storage policies and volumes defined in the [server configuration](../../engines/table-engines/mergetree-family/mergetree.md#table_engine-mergetree-multiple-volumes_configure).

@ -12,3 +12,5 @@ Columns:
 -   `move_factor` ([Float64](../../sql-reference/data-types/float.md)) — Ratio of free disk space. When the ratio exceeds the value of configuration parameter, ClickHouse start to move data to the next volume in order.

 If the storage policy contains more then one volume, then information for each volume is stored in the individual row of the table.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/storage_policies) <!--hide-->
--- a/docs/en/operations/system-tables/table_engines.md
+++ b/docs/en/operations/system-tables/table_engines.md
@ -1,4 +1,4 @@
-# system.table\_engines {#system-table-engines}
+# system.table_engines {#system-table-engines}

 Contains description of table engines supported by server and their feature support information.

@ -33,3 +33,5 @@ WHERE name in ('Kafka', 'MergeTree', 'ReplicatedCollapsingMergeTree')
 -   MergeTree family [query clauses](../../engines/table-engines/mergetree-family/mergetree.md#mergetree-query-clauses)
 -   Kafka [settings](../../engines/table-engines/integrations/kafka.md#table_engine-kafka-creating-a-table)
 -   Join [settings](../../engines/table-engines/special/join.md#join-limitations-and-settings)
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/table_engines) <!--hide-->
--- a/docs/en/operations/system-tables/tables.md
+++ b/docs/en/operations/system-tables/tables.md
@ -51,3 +51,5 @@ This table contains the following columns (the column type is shown in brackets)
 -   `lifetime_bytes` (Nullable(UInt64)) - Total number of bytes INSERTed since server start (only for `Buffer` tables).

 The `system.tables` table is used in `SHOW TABLES` query implementation.
+
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/tables) <!--hide-->
--- a/docs/en/operations/system-tables/text_log.md
+++ b/docs/en/operations/system-tables/text_log.md
@ -1,4 +1,4 @@
-# system.text\_log {#system-tables-text-log}
+# system.text_log {#system-tables-text-log}

 Contains logging entries. Logging level which goes to this table can be limited with `text_log.level` server setting.

@ -24,3 +24,5 @@ Columns:
 -   `revision` (UInt32) — ClickHouse revision.
 -   `source_file` (LowCardinality(String)) — Source file from which the logging was done.
 -   `source_line` (UInt64) — Source line from which the logging was done.
+
+ [Original article](https://clickhouse.tech/docs/en/operations/system_tables/text_log) <!--hide-->
--- a/docs/en/operations/system-tables/trace_log.md
+++ b/docs/en/operations/system-tables/trace_log.md
@ -1,4 +1,4 @@
-# system.trace\_log {#system_tables-trace_log}
+# system.trace_log {#system_tables-trace_log}

 Contains stack traces collected by the sampling query profiler.

@ -46,3 +46,5 @@ thread_number: 48
 query_id:      acc4d61f-5bd1-4a3e-bc91-2180be37c915
 trace:         [94222141367858,94222152240175,94222152325351,94222152329944,94222152330796,94222151449980,94222144088167,94222151682763,94222144088167,94222151682763,94222144088167,94222144058283,94222144059248,94222091840750,94222091842302,94222091831228,94222189631488,140509950166747,140509942945935]
 ```
+
+ [Original article](https://clickhouse.tech/docs/en/operations/system_tables/trace_log) <!--hide-->
--- a/docs/en/operations/system-tables/zookeeper.md
+++ b/docs/en/operations/system-tables/zookeeper.md
@ -68,3 +68,4 @@ numChildren:    7
 pzxid:          987021252247
 path:           /clickhouse/tables/01-08/visits/replicas
 ```
+[Original article](https://clickhouse.tech/docs/en/operations/system_tables/zookeeper) <!--hide-->
--- a/docs/en/sql-reference/aggregate-functions/reference/index.md
+++ b/docs/en/sql-reference/aggregate-functions/reference/index.md
@ -28,7 +28,7 @@ ClickHouse-specific aggregate functions:
 -   [argMin](../../../sql-reference/aggregate-functions/reference/argmin.md)
 -   [argMax](../../../sql-reference/aggregate-functions/reference/argmax.md)
 -   [avgWeighted](../../../sql-reference/aggregate-functions/reference/avgweighted.md)
-   [topK](../../../sql-reference/aggregate-functions/reference/topkweighted.md)
+-   [topK](../../../sql-reference/aggregate-functions/reference/topk.md)
 -   [topKWeighted](../../../sql-reference/aggregate-functions/reference/topkweighted.md)
 -   [groupArray](../../../sql-reference/aggregate-functions/reference/grouparray.md)
 -   [groupUniqArray](../../../sql-reference/aggregate-functions/reference/groupuniqarray.md)
--- a/docs/en/sql-reference/statements/system.md
+++ b/docs/en/sql-reference/statements/system.md
@ -277,8 +277,4 @@ SYSTEM RESTART REPLICA [db.]replicated_merge_tree_family_table_name

 Provides possibility to reinitialize Zookeeper sessions state for all `ReplicatedMergeTree` tables, will compare current state with Zookeeper as source of true and add tasks to Zookeeper queue if needed

-``` sql
-SYSTEM RESTART QUEUES [db.]replicated_merge_tree_family_table_name
-```
-
 [Original article](https://clickhouse.tech/docs/en/query_language/system/) <!--hide-->
--- a/docs/en/sql-reference/table-functions/hdfs.md
+++ b/docs/en/sql-reference/table-functions/hdfs.md
@ -60,7 +60,7 @@ Constructions with `{}` are similar to the [remote table function](../../sql-ref
 -   ‘hdfs://hdfs1:9000/another\_dir/some\_file\_2’
 -   ‘hdfs://hdfs1:9000/another\_dir/some\_file\_3’

-1.  Query the amount of rows in these files:
+2.  Query the amount of rows in these files:

 <!-- -->

@ -69,7 +69,7 @@ SELECT count(*)
 FROM hdfs('hdfs://hdfs1:9000/{some,another}_dir/some_file_{1..3}', 'TSV', 'name String, value UInt32')
 ```

-1.  Query the amount of rows in all files of these two directories:
+3.  Query the amount of rows in all files of these two directories:

 <!-- -->

--- a/docs/ru/engines/table-engines/integrations/index.md
+++ b/docs/ru/engines/table-engines/integrations/index.md
@ -3,4 +3,16 @@ toc_folder_title: Integrations
 toc_priority: 30
 ---

+# Движки таблиц для интеграции {#table-engines-for-integrations}

+Для интеграции с внешними системами ClickHouse предоставляет различные средства, включая движки таблиц. Конфигурирование интеграционных движков осуществляется с помощью запросов `CREATE TABLE` или `ALTER TABLE`, как и для других табличных движков. С точки зрения пользователя, настроенная интеграция выглядит как обычная таблица, но запросы к ней передаются через прокси во внешнюю систему. Этот прозрачный запрос является одним из ключевых преимуществ этого подхода по сравнению с альтернативными методами интеграции, такими как внешние словари или табличные функции, которые требуют использования пользовательских методов запроса при каждом использовании.
+
+Список поддерживаемых интеграций:
+
+-   [ODBC](../../../engines/table-engines/integrations/odbc.md)
+-   [JDBC](../../../engines/table-engines/integrations/jdbc.md)
+-   [MySQL](../../../engines/table-engines/integrations/mysql.md)
+-   [HDFS](../../../engines/table-engines/integrations/hdfs.md)
+-   [Kafka](../../../engines/table-engines/integrations/kafka.md)
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/engines/table-engines/integrations/) <!--hide-->
--- a/docs/ru/engines/table-engines/mergetree-family/replacingmergetree.md
+++ b/docs/ru/engines/table-engines/mergetree-family/replacingmergetree.md
@ -1,6 +1,6 @@
 # ReplacingMergeTree {#replacingmergetree}

-Движок отличается от [MergeTree](mergetree.md#table_engines-mergetree) тем, что выполняет удаление дублирующихся записей с одинаковым значением первичного ключа (точнее, с одинаковым значением [ключа сортировки](mergetree.md)).
+Движок отличается от [MergeTree](mergetree.md#table_engines-mergetree) тем, что выполняет удаление дублирующихся записей с одинаковым значением [ключа сортировки](mergetree.md)).

 Дедупликация данных производится лишь во время слияний. Слияние происходят в фоне в неизвестный момент времени, на который вы не можете ориентироваться. Некоторая часть данных может остаться необработанной. Хотя вы можете вызвать внеочередное слияние с помощью запроса `OPTIMIZE`, на это не стоит рассчитывать, так как запрос `OPTIMIZE` приводит к чтению и записи большого объёма данных.

@ -27,7 +27,7 @@ CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]

 -   `ver` — столбец с версией, тип `UInt*`, `Date` или `DateTime`. Необязательный параметр.

-        При слиянии, из всех строк с одинаковым значением первичного ключа `ReplacingMergeTree` оставляет только одну:
+        При слиянии, из всех строк с одинаковым значением ключа сортировки `ReplacingMergeTree` оставляет только одну:

        - Последнюю в выборке, если `ver` не задан.
        - С максимальной версией, если `ver` задан.
@ -40,7 +40,7 @@ CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]

 <summary>Устаревший способ создания таблицы</summary>

-!!! attention "Attention"
+!!! attention "Внимание"
    Не используйте этот способ в новых проектах и по возможности переведите старые проекты на способ описанный выше.

 ``` sql
--- a/docs/ru/engines/table-engines/special/index.md
+++ b/docs/ru/engines/table-engines/special/index.md
@ -3,4 +3,14 @@ toc_folder_title: Special
 toc_priority: 31
 ---

+# Специальные движки таблиц {#special-table-engines}

+Существует три основные категории движков таблиц:
+
+-   [Семейство MergeTree](../../../engines/table-engines/mergetree-family/index.md) для основного использования.
+-   [Семейство Log](../../../engines/table-engines/log-family/index.md) для небольших временных данных.
+-   [Движки таблиц для интеграции](../../../engines/table-engines/integrations/index.md).
+
+Остальные движки таблиц уникальны по своему назначению и еще не сгруппированы в семейства, поэтому они помещены в эту специальную категорию.
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/engines/table-engines/special/) <!--hide-->
--- a/docs/ru/engines/table-engines/special/materializedview.md
+++ b/docs/ru/engines/table-engines/special/materializedview.md
@ -1,5 +1,5 @@
 # MaterializedView {#materializedview}

-Используется для реализации материализованных представлений (подробнее см. запрос [CREATE TABLE](../../../sql-reference/statements/create.md#create-table-query)). Для хранения данных, использует другой движок, который был указан при создании представления. При чтении из таблицы, просто использует этот движок.
+Используется для реализации материализованных представлений (подробнее см. запрос [CREATE TABLE](../../../sql-reference/statements/create/table.md#create-table-query)). Для хранения данных, использует другой движок, который был указан при создании представления. При чтении из таблицы, просто использует этот движок.

 [Оригинальная статья](https://clickhouse.tech/docs/ru/operations/table_engines/materializedview/) <!--hide-->
--- a/docs/ru/getting-started/tutorial.md
+++ b/docs/ru/getting-started/tutorial.md
@ -99,7 +99,7 @@ As in most databases management systems, ClickHouse logically groups tables into
 clickhouse-client --query "CREATE DATABASE IF NOT EXISTS tutorial"
 ```

-Syntax for creating tables is way more complicated compared to databases (see [reference](../sql-reference/statements/create.md). In general `CREATE TABLE` statement has to specify three key things:
+Syntax for creating tables is way more complicated compared to databases (see [reference](../sql-reference/statements/create/table.md). In general `CREATE TABLE` statement has to specify three key things:

 1.  Name of table to create.
 2.  Table schema, i.e. list of columns and their [data types](../sql-reference/data-types/index.md).
--- a/docs/ru/interfaces/formats.md
+++ b/docs/ru/interfaces/formats.md
@ -7,7 +7,7 @@ ClickHouse может принимать (`INSERT`) и отдавать (`SELECT
 | Формат                                                          | INSERT | SELECT |
 |-----------------------------------------------------------------|--------|--------|
 | [TabSeparated](#tabseparated)                                   | ✔      | ✔      |
-| [TabSeparatedRaw](#tabseparatedraw)                             | ✗      | ✔      |
+| [TabSeparatedRaw](#tabseparatedraw)                             | ✔      | ✔      |
 | [TabSeparatedWithNames](#tabseparatedwithnames)                 | ✔      | ✔      |
 | [TabSeparatedWithNamesAndTypes](#tabseparatedwithnamesandtypes) | ✔      | ✔      |
 | [Template](#format-template)                                    | ✔      | ✔      |
@ -132,7 +132,7 @@ SELECT * FROM nestedt FORMAT TSV
 ## TabSeparatedRaw {#tabseparatedraw}

 Отличается от формата `TabSeparated` тем, что строки выводятся без экранирования.
-Этот формат подходит только для вывода результата выполнения запроса, но не для парсинга (приёма данных для вставки в таблицу).
+Используя этот формат, следите, чтобы в полях не было символов табуляции или разрыва строки.

 Этот формат также доступен под именем `TSVRaw`.

@ -940,7 +940,7 @@ message MessageType {
 }
 ```

-не применяются; вместо них используются определенные в таблице [значения по умолчанию](../sql-reference/statements/create.md#create-default-values).
+не применяются; вместо них используются определенные в таблице [значения по умолчанию](../sql-reference/statements/create/table.md#create-default-values).

 ClickHouse пишет и читает сообщения `Protocol Buffers` в формате `length-delimited`. Это означает, что перед каждым сообщением пишется его длина
 в формате [varint](https://developers.google.com/protocol-buffers/docs/encoding#varints). См. также [как читать и записывать сообщения Protocol Buffers в формате length-delimited в различных языках программирования](https://cwiki.apache.org/confluence/display/GEODE/Delimiting+Protobuf+Messages).
--- a/docs/ru/interfaces/third-party/index.md
+++ b/docs/ru/interfaces/third-party/index.md
@ -4,4 +4,16 @@ toc_folder_title: "\u041E\u0442 \u0441\u0442\u043E\u0440\u043E\u043D\u043D\u0438
 toc_priority: 24
 ---

+# Сторонние интерфейсы {#third-party-interfaces}

+Раздел содержит список сторонних интерфейсов для ClickHouse. Это может быть визуальный интерфейс, интерфейс командной строки, либо API:
+
+-   [Client libraries](../../interfaces/third-party/client-libraries.md)
+-   [Integrations](../../interfaces/third-party/integrations.md)
+-   [GUI](../../interfaces/third-party/gui.md)
+-   [Proxies](../../interfaces/third-party/proxy.md)
+
+!!! note "Примечание"
+    С ClickHouse работают также универсальные инструменты, поддерживающие общий API, такие как [ODBC](../../interfaces/odbc.md) или [JDBC](../../interfaces/jdbc.md).
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/interfaces/third-party/) <!--hide-->
--- a/docs/ru/operations/access-rights.md
+++ b/docs/ru/operations/access-rights.md
@ -55,7 +55,7 @@ ClickHouse поддерживает управление доступом на

 Запросы управления:

- [CREATE USER](../sql-reference/statements/create.md#create-user-statement)
+- [CREATE USER](../sql-reference/statements/create/user.md#create-user-statement)
 - [ALTER USER](../sql-reference/statements/alter.md#alter-user-statement)
 - [DROP USER](../sql-reference/statements/misc.md#drop-user-statement)
 - [SHOW CREATE USER](../sql-reference/statements/show.md#show-create-user-statement)
@ -82,7 +82,7 @@ ClickHouse поддерживает управление доступом на

 Запросы управления:

- [CREATE ROLE](../sql-reference/statements/create.md#create-role-statement)
+- [CREATE ROLE](../sql-reference/statements/create/index.md#create-role-statement)
 - [ALTER ROLE](../sql-reference/statements/alter.md#alter-role-statement)
 - [DROP ROLE](../sql-reference/statements/misc.md#drop-role-statement)
 - [SET ROLE](../sql-reference/statements/misc.md#set-role-statement)
@ -97,7 +97,7 @@ ClickHouse поддерживает управление доступом на

 Запросы управления:

- [CREATE ROW POLICY](../sql-reference/statements/create.md#create-row-policy-statement)
+- [CREATE ROW POLICY](../sql-reference/statements/create/index.md#create-row-policy-statement)
 - [ALTER ROW POLICY](../sql-reference/statements/alter.md#alter-row-policy-statement)
 - [DROP ROW POLICY](../sql-reference/statements/misc.md#drop-row-policy-statement)
 - [SHOW CREATE ROW POLICY](../sql-reference/statements/show.md#show-create-row-policy-statement)
@ -109,7 +109,7 @@ ClickHouse поддерживает управление доступом на

 Запросы управления:

- [CREATE SETTINGS PROFILE](../sql-reference/statements/create.md#create-settings-profile-statement)
+- [CREATE SETTINGS PROFILE](../sql-reference/statements/create/index.md#create-settings-profile-statement)
 - [ALTER SETTINGS PROFILE](../sql-reference/statements/alter.md#alter-settings-profile-statement)
 - [DROP SETTINGS PROFILE](../sql-reference/statements/misc.md#drop-settings-profile-statement)
 - [SHOW CREATE SETTINGS PROFILE](../sql-reference/statements/show.md#show-create-settings-profile-statement)
@ -123,7 +123,7 @@ ClickHouse поддерживает управление доступом на

 Запросы управления:

- [CREATE QUOTA](../sql-reference/statements/create.md#create-quota-statement)
+- [CREATE QUOTA](../sql-reference/statements/create/index.md#create-quota-statement)
 - [ALTER QUOTA](../sql-reference/statements/alter.md#alter-quota-statement)
 - [DROP QUOTA](../sql-reference/statements/misc.md#drop-quota-statement)
 - [SHOW CREATE QUOTA](../sql-reference/statements/show.md#show-create-quota-statement)
--- a/docs/ru/operations/index.md
+++ b/docs/ru/operations/index.md
@ -17,7 +17,7 @@ toc_title: intro
 - [Резервное копирование](backup.md)
 - [Конфигурационные файлы](configuration-files.md)
 - [Квоты](quotas.md)
- [Системные таблицы](system-tables.md)
+- [Системные таблицы](system-tables/index.md)
 - [Конфигурационные параметры сервера](server-configuration-parameters/index.md)
 - [Тестирование серверов с помощью ClickHouse](performance-test.md)
 - [Настройки](settings/index.md#settings)
--- a/docs/ru/operations/monitoring.md
+++ b/docs/ru/operations/monitoring.md
@ -28,7 +28,7 @@ ClickHouse собирает:
 -   Различные метрики того, как сервер использует вычислительные ресурсы.
 -   Общую статистику обработки запросов.

-Метрики находятся в таблицах [system.metrics](system-tables.md#system_tables-metrics), [system.events](system-tables.md#system_tables-events) и [system.asynchronous\_metrics](system-tables.md#system_tables-asynchronous_metrics).
+Метрики находятся в таблицах [system.metrics](system-tables/metrics.md#system_tables-metrics), [system.events](system-tables/events.md#system_tables-events) и [system.asynchronous_metrics](system-tables/asynchronous_metrics.md#system_tables-asynchronous_metrics).

 Можно настроить экспорт метрик из ClickHouse в [Graphite](https://github.com/graphite-project). Смотрите секцию [graphite](server-configuration-parameters/settings.md#server_configuration_parameters-graphite) конфигурационного файла ClickHouse. Перед настройкой экспорта метрик необходимо настроить Graphite, как указано в [официальном руководстве](https://graphite.readthedocs.io/en/latest/install.html).

@ -37,3 +37,5 @@ ClickHouse собирает:
 Также, можно отслеживать доступность сервера через HTTP API. Отправьте `HTTP GET` к ресурсу `/ping`. Если сервер доступен, он отвечает `200 OK`.

 Для мониторинга серверов в кластерной конфигурации необходимо установить параметр [max\_replica\_delay\_for\_distributed\_queries](settings/settings.md#settings-max_replica_delay_for_distributed_queries) и использовать HTTP ресурс `/replicas_status`. Если реплика доступна и не отстаёт от других реплик, то запрос к `/replicas_status` возвращает `200 OK`. Если реплика отстаёт, то запрос возвращает `503 HTTP_SERVICE_UNAVAILABLE`, включая информацию о размере отставания.
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/operations/system_tables/monitoring) <!--hide-->
--- a/docs/ru/operations/optimizing-performance/sampling-query-profiler.md
+++ b/docs/ru/operations/optimizing-performance/sampling-query-profiler.md
@ -11,7 +11,7 @@ To use profiler:

 -   Setup the [trace\_log](../../operations/server-configuration-parameters/settings.md#server_configuration_parameters-trace_log) section of the server configuration.

-    This section configures the [trace\_log](../../operations/system-tables.md#system_tables-trace_log) system table containing the results of the profiler functioning. It is configured by default. Remember that data in this table is valid only for a running server. After the server restart, ClickHouse doesn’t clean up the table and all the stored virtual memory address may become invalid.
+    This section configures the [trace_log](../../operations/system-tables/trace_log.md#system_tables-trace_log) system table containing the results of the profiler functioning. It is configured by default. Remember that data in this table is valid only for a running server. After the server restart, ClickHouse doesn’t clean up the table and all the stored virtual memory address may become invalid.

 -   Setup the [query\_profiler\_cpu\_time\_period\_ns](../../operations/settings/settings.md#query_profiler_cpu_time_period_ns) or [query\_profiler\_real\_time\_period\_ns](../../operations/settings/settings.md#query_profiler_real_time_period_ns) settings. Both settings can be used simultaneously.

--- a/docs/ru/operations/server-configuration-parameters/settings.md
+++ b/docs/ru/operations/server-configuration-parameters/settings.md
@ -576,9 +576,9 @@ ClickHouse проверит условия `min_part_size` и `min_part_size_rat

 -   `endpoint` – путь по которому будет осуществляться экспорт данных метрик по HTTP протоколу для сбора с помощью prometheus. Должен начинаться с ‘/’.
 -   `port` – порт по которому будет доступен endpoint для сбора метрик.
-   `metrics` – флаг для экспорта текущих значений метрик из таблицы [system.metrics](../system-tables.md#system_tables-metrics).
-   `events` – флаг для экспорта текущих значений метрик из таблицы [system.events](../system-tables.md#system_tables-events).
-   `asynchronous_metrics` – флаг для экспорта текущих значений значения метрик из таблицы [system.asynchronous\_metrics](../system-tables.md#system_tables-asynchronous_metrics).
+-   `metrics` – флаг для экспорта текущих значений метрик из таблицы [system.metrics](../system-tables/metrics.md#system_tables-metrics).
+-   `events` – флаг для экспорта текущих значений метрик из таблицы [system.events](../system-tables/events.md#system_tables-events).
+-   `asynchronous_metrics` – флаг для экспорта текущих значений значения метрик из таблицы [system.asynchronous\_metrics](../system-tables/asynchronous_metrics.md#system_tables-asynchronous_metrics).

 **Пример**

--- a/docs/ru/operations/settings/settings.md
+++ b/docs/ru/operations/settings/settings.md
@ -1227,7 +1227,7 @@ Default value: 1000000000 nanoseconds (once a second).

 See also:

-   System table [trace\_log](../../operations/system-tables.md#system_tables-trace_log)
+-   System table [trace\_log](../../operations/system-tables/trace_log.md#system_tables-trace_log)

 ## query\_profiler\_cpu\_time\_period\_ns {#query_profiler_cpu_time_period_ns}

@ -1250,9 +1250,9 @@ Default value: 1000000000 nanoseconds.

 See also:

-   System table [trace\_log](../../operations/system-tables.md#system_tables-trace_log)
+-   System table [trace\_log](../../operations/system-tables/trace_log.md#system_tables-trace_log)

-## allow\_introspection\_functions {#settings-allow_introspection_functions}
+## allow_introspection_functions {#settings-allow_introspection_functions}

 Enables of disables [introspections functions](../../sql-reference/functions/introspection.md) for query profiling.

@ -1266,9 +1266,9 @@ Default value: 0.
 **See Also**

 -   [Sampling Query Profiler](../optimizing-performance/sampling-query-profiler.md)
-   System table [trace\_log](../../operations/system-tables.md#system_tables-trace_log)
+-   System table [trace\_log](../../operations/system-tables/trace_log.md#system_tables-trace_log)

-## background\_pool\_size {#background_pool_size}
+## background_pool_size {#background_pool_size}

 Задает количество потоков для выполнения фоновых операций в движках таблиц (например, слияния в таблицах c движком [MergeTree](../../engines/table-engines/mergetree-family/index.md)). Настройка применяется при запуске сервера ClickHouse и не может быть изменена во пользовательском сеансе. Настройка позволяет управлять загрузкой процессора и диска. Чем меньше пулл, тем ниже нагрузка на CPU и диск, при этом фоновые процессы замедляются, что может повлиять на скорость выполнения запроса.

@ -1452,7 +1452,7 @@ SELECT idx, i FROM null_in WHERE i IN (1, NULL) SETTINGS transform_null_in = 1;

 ## min_insert_block_size_rows_for_materialized_views {#min-insert-block-size-rows-for-materialized-views}

-Устанавливает минимальное количество строк в блоке, который может быть вставлен в таблицу запросом `INSERT`. Блоки меньшего размера склеиваются в блоки большего размера. Настройка применяется только для блоков, вставляемых в [материализованное представление](../../sql-reference/statements/create.md#create-view). Настройка позволяет избежать избыточного потребления памяти.
+Устанавливает минимальное количество строк в блоке, который может быть вставлен в таблицу запросом `INSERT`. Блоки меньшего размера склеиваются в блоки большего размера. Настройка применяется только для блоков, вставляемых в [материализованное представление](../../sql-reference/statements/create/view.md#create-view). Настройка позволяет избежать избыточного потребления памяти.

 Допустимые значения:

@ -1467,7 +1467,7 @@ SELECT idx, i FROM null_in WHERE i IN (1, NULL) SETTINGS transform_null_in = 1;

 ## min_insert_block_size_bytes_for_materialized_views {#min-insert-block-size-bytes-for-materialized-views}

-Устанавливает минимальное количество байтов в блоке, который может быть вставлен в таблицу запросом `INSERT`. Блоки меньшего размера склеиваются в блоки большего размера. Настройка применяется только для блоков, вставляемых в [материализованное представление](../../sql-reference/statements/create.md#create-view). Настройка позволяет избежать избыточного потребления памяти.
+Устанавливает минимальное количество байтов в блоке, который может быть вставлен в таблицу запросом `INSERT`. Блоки меньшего размера склеиваются в блоки большего размера. Настройка применяется только для блоков, вставляемых в [материализованное представление](../../sql-reference/statements/create/view.md#create-view). Настройка позволяет избежать избыточного потребления памяти.

 Допустимые значения:

--- a/docs/ru/operations/system-tables.md
+++ b/docs/ru/operations/system-tables.md
--- a/docs/ru/operations/system-tables/asynchronous_metric_log.md
+++ b/docs/ru/operations/system-tables/asynchronous_metric_log.md
@ -0,0 +1,36 @@
+## system.asynchronous_metric_log {#system-tables-async-log}
+
+Содержит исторические значения метрик из таблицы `system.asynchronous_metrics`, которые сохраняются раз в минуту. По умолчанию включена.
+
+Столбцы:
+-   `event_date` ([Date](../../sql-reference/data-types/date.md)) — дата события.
+-   `event_time` ([DateTime](../../sql-reference/data-types/datetime.md)) — время события.
+-   `name` ([String](../../sql-reference/data-types/string.md)) — название метрики.
+-   `value` ([Float64](../../sql-reference/data-types/float.md)) — значение метрики.
+
+**Пример**
+
+``` sql
+SELECT * FROM system.asynchronous_metric_log LIMIT 10
+```
+
+``` text
+┌─event_date─┬──────────event_time─┬─name─────────────────────────────────────┬────value─┐
+│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.arenas.all.pmuzzy               │        0 │
+│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.arenas.all.pdirty               │     4214 │
+│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.background_thread.run_intervals │        0 │
+│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.background_thread.num_runs      │        0 │
+│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.retained                        │ 17657856 │
+│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.mapped                          │ 71471104 │
+│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.resident                        │ 61538304 │
+│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.metadata                        │  6199264 │
+│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.allocated                       │ 38074336 │
+│ 2020-06-22 │ 2020-06-22 06:57:30 │ jemalloc.epoch                           │        2 │
+└────────────┴─────────────────────┴──────────────────────────────────────────┴──────────┘
+```
+
+**Смотрите также**
+- [system.asynchronous_metrics](#system_tables-asynchronous_metrics) — Содержит метрики, которые периодически вычисляются в фоновом режиме. 
+- [system.metric_log](#system_tables-metric_log) — таблица фиксирующая историю значений метрик из `system.metrics` и `system.events`.
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/operations/system_tables/asynchronous_metric_log) <!--hide-->
--- a/docs/ru/operations/system-tables/asynchronous_metrics.md
+++ b/docs/ru/operations/system-tables/asynchronous_metrics.md
@ -0,0 +1,39 @@
+# system.asynchronous_metrics {#system_tables-asynchronous_metrics}
+
+Содержит метрики, которые периодически вычисляются в фоновом режиме. Например, объём используемой оперативной памяти.
+
+Столбцы:
+
+-   `metric` ([String](../../sql-reference/data-types/string.md)) — название метрики.
+-   `value` ([Float64](../../sql-reference/data-types/float.md)) — значение метрики.
+
+**Пример**
+
+``` sql
+SELECT * FROM system.asynchronous_metrics LIMIT 10
+```
+
+``` text
+┌─metric──────────────────────────────────┬──────value─┐
+│ jemalloc.background_thread.run_interval │          0 │
+│ jemalloc.background_thread.num_runs     │          0 │
+│ jemalloc.background_thread.num_threads  │          0 │
+│ jemalloc.retained                       │  422551552 │
+│ jemalloc.mapped                         │ 1682989056 │
+│ jemalloc.resident                       │ 1656446976 │
+│ jemalloc.metadata_thp                   │          0 │
+│ jemalloc.metadata                       │   10226856 │
+│ UncompressedCacheCells                  │          0 │
+│ MarkCacheFiles                          │          0 │
+└─────────────────────────────────────────┴────────────┘
+```
+
+**Смотрите также**
+
+-   [Мониторинг](../../operations/monitoring.md) — основы мониторинга в ClickHouse.
+-   [system.metrics](#system_tables-metrics) — таблица с мгновенно вычисляемыми метриками.
+-   [system.events](#system_tables-events) — таблица с количеством произошедших событий.
+-   [system.metric\_log](#system_tables-metric_log) — таблица фиксирующая историю значений метрик из `system.metrics` и `system.events`.
+
+ [Оригинальная статья](https://clickhouse.tech/docs/ru/operations/system_tables/asynchronous_metrics) <!--hide-->
+ 
--- a/docs/ru/operations/system-tables/clusters.md
+++ b/docs/ru/operations/system-tables/clusters.md
@ -0,0 +1,16 @@
+# system.clusters {#system-clusters}
+
+Содержит информацию о доступных в конфигурационном файле кластерах и серверах, которые в них входят.
+
+Столбцы:
+
+-   `cluster` (String) — имя кластера.
+-   `shard_num` (UInt32) — номер шарда в кластере, начиная с 1.
+-   `shard_weight` (UInt32) — относительный вес шарда при записи данных.
+-   `replica_num` (UInt32) — номер реплики в шарде, начиная с 1.
+-   `host_name` (String) — хост, указанный в конфигурации.
+-   `host_address` (String) — TIP-адрес хоста, полученный из DNS.
+-   `port` (UInt16) — порт, на который обращаться для соединения с сервером.
+-   `user` (String) — имя пользователя, которого использовать для соединения с сервером.
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/operations/system_tables/clusters) <!--hide-->
--- a/docs/ru/operations/system-tables/columns.md
+++ b/docs/ru/operations/system-tables/columns.md
@ -0,0 +1,24 @@
+# system.columns {#system-columns}
+
+Содержит информацию о столбцах всех таблиц.
+
+С помощью этой таблицы можно получить информацию аналогично запросу [DESCRIBE TABLE](../../sql-reference/statements/misc.md#misc-describe-table), но для многих таблиц сразу.
+
+Таблица `system.columns` содержит столбцы (тип столбца указан в скобках):
+
+-   `database` (String) — имя базы данных.
+-   `table` (String) — имя таблицы.
+-   `name` (String) — имя столбца.
+-   `type` (String) — тип столбца.
+-   `default_kind` (String) — тип выражения (`DEFAULT`, `MATERIALIZED`, `ALIAS`) значения по умолчанию, или пустая строка.
+-   `default_expression` (String) — выражение для значения по умолчанию или пустая строка.
+-   `data_compressed_bytes` (UInt64) — размер сжатых данных в байтах.
+-   `data_uncompressed_bytes` (UInt64) — размер распакованных данных в байтах.
+-   `marks_bytes` (UInt64) — размер засечек в байтах.
+-   `comment` (String) — комментарий к столбцу или пустая строка.
+-   `is_in_partition_key` (UInt8) — флаг, показывающий включение столбца в ключ партиционирования.
+-   `is_in_sorting_key` (UInt8) — флаг, показывающий включение столбца в ключ сортировки.
+-   `is_in_primary_key` (UInt8) — флаг, показывающий включение столбца в первичный ключ.
+-   `is_in_sampling_key` (UInt8) — флаг, показывающий включение столбца в ключ выборки.
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/operations/system_tables/columns) <!--hide-->
--- a/docs/ru/operations/system-tables/contributors.md
+++ b/docs/ru/operations/system-tables/contributors.md
@ -0,0 +1,42 @@
+# system.contributors {#system-contributors}
+
+Содержит информацию о контрибьютерах. Контрибьютеры расположены в таблице в случайном порядке. Порядок определяется заново при каждом запросе.
+
+Столбцы:
+
+-   `name` (String) — Имя контрибьютера (автора коммита) из git log.
+
+**Пример**
+
+``` sql
+SELECT * FROM system.contributors LIMIT 10
+```
+
+``` text
+┌─name─────────────┐
+│ Olga Khvostikova │
+│ Max Vetrov       │
+│ LiuYangkuan      │
+│ svladykin        │
+│ zamulla          │
+│ Šimon Podlipský  │
+│ BayoNet          │
+│ Ilya Khomutov    │
+│ Amy Krishnevsky  │
+│ Loud_Scream      │
+└──────────────────┘
+```
+
+Чтобы найти себя в таблице, выполните запрос:
+
+``` sql
+SELECT * FROM system.contributors WHERE name='Olga Khvostikova'
+```
+
+``` text
+┌─name─────────────┐
+│ Olga Khvostikova │
+└──────────────────┘
+```
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/operations/system_tables/contributors) <!--hide-->
--- a/docs/ru/operations/system-tables/current-roles.md
+++ b/docs/ru/operations/system-tables/current-roles.md
@ -0,0 +1,11 @@
+# system.current_roles {#system_tables-current_roles}
+
+Содержит активные роли текущего пользователя. `SET ROLE` изменяет содержимое этой таблицы.
+
+Столбцы:
+
+ - `role_name` ([String](../../sql-reference/data-types/string.md))) — Имя роли.
+ - `with_admin_option` ([UInt8](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Флаг, который показывает, обладает ли `current_role` роль привилегией `ADMIN OPTION`.
+ - `is_default` ([UInt8](../../sql-reference/data-types/int-uint.md#uint-ranges)) —  Флаг, который показывает, является ли `current_role` ролью по умолчанию. 
+
+ [Оригинальная статья](https://clickhouse.tech/docs/ru/operations/system_tables/current-roles) <!--hide-->
--- a/docs/ru/operations/system-tables/data_type_families.md
+++ b/docs/ru/operations/system-tables/data_type_families.md
@ -0,0 +1,36 @@
+# system.data_type_families {#system_tables-data_type_families}
+
+Содержит информацию о поддерживаемых [типах данных](../../sql-reference/data-types/).
+
+Столбцы:
+
+-   `name` ([String](../../sql-reference/data-types/string.md)) — имя типа данных.
+-   `case_insensitive` ([UInt8](../../sql-reference/data-types/int-uint.md)) — свойство, которое показывает, зависит ли имя типа данных в запросе от регистра. Например, допустимы и `Date`, и `date`.
+-   `alias_to` ([String](../../sql-reference/data-types/string.md)) — тип данных, для которого `name` является алиасом.
+
+**Пример**
+
+``` sql
+SELECT * FROM system.data_type_families WHERE alias_to = 'String'
+```
+
+``` text
+┌─name───────┬─case_insensitive─┬─alias_to─┐
+│ LONGBLOB   │                1 │ String   │
+│ LONGTEXT   │                1 │ String   │
+│ TINYTEXT   │                1 │ String   │
+│ TEXT       │                1 │ String   │
+│ VARCHAR    │                1 │ String   │
+│ MEDIUMBLOB │                1 │ String   │
+│ BLOB       │                1 │ String   │
+│ TINYBLOB   │                1 │ String   │
+│ CHAR       │                1 │ String   │
+│ MEDIUMTEXT │                1 │ String   │
+└────────────┴──────────────────┴──────────┘
+```
+
+**See Also**
+
+-   [Синтаксис](../../sql-reference/syntax.md) — поддерживаемый SQL синтаксис.
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/operations/system_tables/data_type_families) <!--hide-->
--- a/docs/ru/operations/system-tables/databases.md
+++ b/docs/ru/operations/system-tables/databases.md
@ -0,0 +1,7 @@
+# system.databases {#system-databases}
+
+Таблица содержит один столбец name типа String - имя базы данных.
+Для каждой базы данных, о которой знает сервер, будет присутствовать соответствующая запись в таблице.
+Эта системная таблица используется для реализации запроса `SHOW DATABASES`.
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/operations/system_tables/databases) <!--hide-->
--- a/Show More
+++ b/Show More