Merge remote-tracking branch 'origin/master' into HEAD

.github/ISSUE_TEMPLATE/95_sanitizer-report.md

@@ -0,0 +1,19 @@
+---
+name: Sanitizer alert
+about: Potential issue has been found by special code instrumentation
+title: ''
+labels: testing
+assignees: ''
+
+---
+
+(you don't have to strictly follow this form)
+
+**Describe the bug**
+A link to the report
+
+**How to reproduce**
+Try to reproduce the report and copy the tables and queries involved.
+
+**Error message and/or stacktrace**
+You can find additional information in server logs.

.gitmodules

@@ -84,7 +84,7 @@
 	url = https://github.com/google/brotli.git
 [submodule "contrib/h3"]
 	path = contrib/h3
-	url = https://github.com/uber/h3
+	url = https://github.com/ClickHouse-Extras/h3
 [submodule "contrib/hyperscan"]
 	path = contrib/hyperscan
 	url = https://github.com/ClickHouse-Extras/hyperscan.git
@@ -184,7 +184,7 @@
 	url = https://github.com/ClickHouse-Extras/krb5
 [submodule "contrib/cyrus-sasl"]
 	path = contrib/cyrus-sasl
-	url = https://github.com/cyrusimap/cyrus-sasl
+	url = https://github.com/ClickHouse-Extras/cyrus-sasl
 	branch = cyrus-sasl-2.1
 [submodule "contrib/croaring"]
 	path = contrib/croaring

.pylintrc

@@ -0,0 +1,45 @@
+# vim: ft=config
+
+[BASIC]
+max-module-lines=2000
+# due to SQL
+max-line-length=200
+# Drop/decrease them one day:
+max-branches=50
+max-nested-blocks=10
+max-statements=200
+
+[FORMAT]
+ignore-long-lines = (# )?<?https?://\S+>?$
+
+[MESSAGES CONTROL]
+disable = bad-continuation,
+          missing-docstring,
+          bad-whitespace,
+          too-few-public-methods,
+          invalid-name,
+          too-many-arguments,
+          keyword-arg-before-vararg,
+          too-many-locals,
+          too-many-instance-attributes,
+          cell-var-from-loop,
+          fixme,
+          too-many-public-methods,
+          wildcard-import,
+          unused-wildcard-import,
+          singleton-comparison,
+          # pytest.mark.parametrize is not callable (not-callable)
+          not-callable,
+          # https://github.com/PyCQA/pylint/issues/3882
+          # [Python 3.9] Value 'Optional' is unsubscriptable (unsubscriptable-object) (also Union)
+          unsubscriptable-object,
+          # Drop them one day:
+          redefined-outer-name,
+          broad-except,
+          bare-except,
+          no-else-return,
+          global-statement
+
+[SIMILARITIES]
+# due to SQL
+min-similarity-lines=1000

LICENSE

@@ -1,4 +1,4 @@
-Copyright 2016-2020 Yandex LLC
+Copyright 2016-2021 Yandex LLC
 
                                  Apache License
                            Version 2.0, January 2004
@@ -188,7 +188,7 @@ Copyright 2016-2020 Yandex LLC
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright 2016-2020 Yandex LLC
+   Copyright 2016-2021 Yandex LLC
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

README.md

@@ -16,5 +16,4 @@ ClickHouse® is an open-source column-oriented database management system that a
 * You can also [fill this form](https://clickhouse.tech/#meet) to meet Yandex ClickHouse team in person.
 
 ## Upcoming Events
-* [SF Bay Area ClickHouse Virtual Office Hours (online)](https://www.meetup.com/San-Francisco-Bay-Area-ClickHouse-Meetup/events/274273549/) on 20 January 2020.
+* [Chinese ClickHouse Meetup (online)](http://hdxu.cn/8KxZE) on 6 February 2021.
-* [Chinese ClickHouse Meetup (online)](http://hdxu.cn/8KxZE) on 6 February 2020.

SECURITY.md

@@ -15,9 +15,13 @@ currently being supported with security updates:
 | 20.4   | :x: |
 | 20.5   | :x: |
 | 20.6   | :x: |
-| 20.7   | :white_check_mark: |
+| 20.7   | :x: |
 | 20.8   | :white_check_mark: |
-| 20.9   | :white_check_mark: |
+| 20.9   | :x: |
+| 20.10  | :x: |
+| 20.11  | :white_check_mark: |
+| 20.12  | :white_check_mark: |
+| 21.1   | :white_check_mark: |
 
 ## Reporting a Vulnerability
 

base/common/DateLUTImpl.h

@@ -229,8 +229,12 @@ public:
 
     inline UInt8 daysInMonth(UInt16 year, UInt8 month) const
     {
+        UInt16 idx = year - DATE_LUT_MIN_YEAR;
+        if (unlikely(idx >= DATE_LUT_YEARS))
+            return 31;  /// Implementation specific behaviour on overflow.
+
         /// 32 makes arithmetic more simple.
-        DayNum any_day_of_month = DayNum(years_lut[year - DATE_LUT_MIN_YEAR] + 32 * (month - 1));
+        DayNum any_day_of_month = DayNum(years_lut[idx] + 32 * (month - 1));
         return lut[any_day_of_month].days_in_month;
     }
 
@@ -767,7 +771,7 @@ public:
     /// Adding calendar intervals.
     /// Implementation specific behaviour when delta is too big.
 
-    inline time_t addDays(time_t t, Int64 delta) const
+    inline NO_SANITIZE_UNDEFINED time_t addDays(time_t t, Int64 delta) const
     {
         DayNum index = findIndex(t);
         time_t time_offset = toHour(t) * 3600 + toMinute(t) * 60 + toSecond(t);
@@ -780,7 +784,7 @@ public:
         return lut[index].date + time_offset;
     }
 
-    inline time_t addWeeks(time_t t, Int64 delta) const
+    inline NO_SANITIZE_UNDEFINED time_t addWeeks(time_t t, Int64 delta) const
     {
         return addDays(t, delta * 7);
     }
@@ -812,7 +816,7 @@ public:
         return lut[result_day].date + time_offset;
     }
 
-    inline DayNum addMonths(DayNum d, Int64 delta) const
+    inline NO_SANITIZE_UNDEFINED DayNum addMonths(DayNum d, Int64 delta) const
     {
         const Values & values = lut[d];
 
@@ -836,18 +840,18 @@ public:
         }
     }
 
-    inline time_t addQuarters(time_t t, Int64 delta) const
+    inline NO_SANITIZE_UNDEFINED time_t addQuarters(time_t t, Int64 delta) const
     {
         return addMonths(t, delta * 3);
     }
 
-    inline DayNum addQuarters(DayNum d, Int64 delta) const
+    inline NO_SANITIZE_UNDEFINED DayNum addQuarters(DayNum d, Int64 delta) const
     {
         return addMonths(d, delta * 3);
     }
 
     /// Saturation can occur if 29 Feb is mapped to non-leap year.
-    inline time_t addYears(time_t t, Int64 delta) const
+    inline NO_SANITIZE_UNDEFINED time_t addYears(time_t t, Int64 delta) const
     {
         DayNum result_day = addYears(toDayNum(t), delta);
 
@@ -859,7 +863,7 @@ public:
         return lut[result_day].date + time_offset;
     }
 
-    inline DayNum addYears(DayNum d, Int64 delta) const
+    inline NO_SANITIZE_UNDEFINED DayNum addYears(DayNum d, Int64 delta) const
     {
         const Values & values = lut[d];
 

base/common/defines.h

@@ -84,10 +84,12 @@
 #    define NO_SANITIZE_UNDEFINED __attribute__((__no_sanitize__("undefined")))
 #    define NO_SANITIZE_ADDRESS __attribute__((__no_sanitize__("address")))
 #    define NO_SANITIZE_THREAD __attribute__((__no_sanitize__("thread")))
+#    define ALWAYS_INLINE_NO_SANITIZE_UNDEFINED __attribute__((__always_inline__, __no_sanitize__("undefined")))
 #else  /// It does not work in GCC. GCC 7 cannot recognize this attribute and GCC 8 simply ignores it.
 #    define NO_SANITIZE_UNDEFINED
 #    define NO_SANITIZE_ADDRESS
 #    define NO_SANITIZE_THREAD
+#    define ALWAYS_INLINE_NO_SANITIZE_UNDEFINED ALWAYS_INLINE
 #endif
 
 /// A template function for suppressing warnings about unused variables or function results.

base/common/extended_types.h

@@ -104,8 +104,3 @@ template <> struct is_big_int<wUInt256> { static constexpr bool value = true; };
 template <typename T>
 inline constexpr bool is_big_int_v = is_big_int<T>::value;
 
-template <typename To, typename From>
-inline To bigint_cast(const From & x [[maybe_unused]])
-{
-    return static_cast<To>(x);
-}

base/glibc-compatibility/CMakeLists.txt

@@ -27,9 +27,12 @@ if (GLIBC_COMPATIBILITY)
         list(APPEND glibc_compatibility_sources musl/getentropy.c)
     endif()
 
+    if (NOT ARCH_ARM)
+        # clickhouse_memcpy don't support ARCH_ARM, see https://github.com/ClickHouse/ClickHouse/issues/18951
         add_library (clickhouse_memcpy OBJECT
             ${ClickHouse_SOURCE_DIR}/contrib/FastMemcpy/memcpy_wrapper.c
         )
+    endif()
 
     # Need to omit frame pointers to match the performance of glibc
     set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fomit-frame-pointer")

base/glibc-compatibility/musl/sched_getcpu.c

@@ -31,7 +31,7 @@ static void *volatile vdso_func = (void *)getcpu_init;
 int sched_getcpu(void)
 {
 	int r;
-	unsigned cpu;
+	unsigned cpu = 0;
 
 #ifdef VDSO_GETCPU_SYM
 	getcpu_f f = (getcpu_f)vdso_func;

base/harmful/harmful.c

@@ -118,7 +118,9 @@ TRAP(logout)
 TRAP(logwtmp)
 TRAP(lrand48)
 TRAP(mallinfo)
-TRAP(mallopt)
+#if !defined(SANITIZER)
+TRAP(mallopt) // Used by tsan
+#endif
 TRAP(mblen)
 TRAP(mbrlen)
 TRAP(mbrtowc)
@@ -193,7 +195,9 @@ TRAP(dbm_nextkey)
 TRAP(dbm_open)
 TRAP(dbm_store)
 TRAP(dirname)
-TRAP(dlerror)
+#if !defined(SANITIZER)
+TRAP(dlerror) // Used by tsan
+#endif
 TRAP(ftw)
 TRAP(getc_unlocked)
 //TRAP(getenv) // Ok at program startup

base/mysqlxx/Connection.cpp

@@ -116,8 +116,8 @@ void Connection::connect(const char* db,
     if (!mysql_real_connect(driver.get(), server, user, password, db, port, ifNotEmpty(socket), driver->client_flag))
         throw ConnectionFailed(errorMessage(driver.get()), mysql_errno(driver.get()));
 
-    /// Sets UTF-8 as default encoding.
+    /// Sets UTF-8 as default encoding. See https://mariadb.com/kb/en/mysql_set_character_set/
-    if (mysql_set_character_set(driver.get(), "UTF8"))
+    if (mysql_set_character_set(driver.get(), "utf8mb4"))
         throw ConnectionFailed(errorMessage(driver.get()), mysql_errno(driver.get()));
 
     is_connected = true;

cmake/autogenerated_versions.txt

@@ -1,9 +1,9 @@
 # This strings autochanged from release_lib.sh:
-SET(VERSION_REVISION 54445)
+SET(VERSION_REVISION 54448)
 SET(VERSION_MAJOR 21)
-SET(VERSION_MINOR 1)
+SET(VERSION_MINOR 3)
 SET(VERSION_PATCH 1)
-SET(VERSION_GITHASH 667dd0cf0ccecdaa6f334177b7ece2f53bd196a1)
+SET(VERSION_GITHASH ef72ba7349f230321750c13ee63b49a11a7c0adc)
-SET(VERSION_DESCRIBE v21.1.1.5646-prestable)
+SET(VERSION_DESCRIBE v21.3.1.1-prestable)
-SET(VERSION_STRING 21.1.1.5646)
+SET(VERSION_STRING 21.3.1.1)
 # end of autochange

cmake/find/rdkafka.cmake

@@ -1,10 +1,4 @@
-if (NOT ARCH_ARM AND OPENSSL_FOUND)
+option (ENABLE_RDKAFKA "Enable kafka" ${ENABLE_LIBRARIES})
-    option (ENABLE_RDKAFKA "Enable kafka" ${ENABLE_LIBRARIES})
-elseif(ENABLE_RDKAFKA AND NOT OPENSSL_FOUND)
-    message (${RECONFIGURE_MESSAGE_LEVEL} "Can't use librdkafka without SSL")
-elseif(ENABLE_RDKAFKA)
-    message (${RECONFIGURE_MESSAGE_LEVEL} "librdafka is not supported on ARM and on FreeBSD")
-endif ()
 
 if (NOT ENABLE_RDKAFKA)
     if (USE_INTERNAL_RDKAFKA_LIBRARY)
@@ -13,11 +7,7 @@ if (NOT ENABLE_RDKAFKA)
     return()
 endif()
 
-if (NOT ARCH_ARM)
+option (USE_INTERNAL_RDKAFKA_LIBRARY "Set to FALSE to use system librdkafka instead of the bundled" ${NOT_UNBUNDLED})
-    option (USE_INTERNAL_RDKAFKA_LIBRARY "Set to FALSE to use system librdkafka instead of the bundled" ${NOT_UNBUNDLED})
-elseif(USE_INTERNAL_RDKAFKA_LIBRARY)
-    message (${RECONFIGURE_MESSAGE_LEVEL} "Can't use internal librdkafka with ARCH_ARM=${ARCH_ARM}")
-endif ()
 
 if (NOT EXISTS "${ClickHouse_SOURCE_DIR}/contrib/cppkafka/CMakeLists.txt")
     if(USE_INTERNAL_RDKAFKA_LIBRARY)
@@ -67,14 +57,12 @@ if (RDKAFKA_LIB AND RDKAFKA_INCLUDE_DIR)
     if (LZ4_LIBRARY)
        list (APPEND RDKAFKA_LIBRARY ${LZ4_LIBRARY})
     endif ()
-elseif (NOT MISSING_INTERNAL_RDKAFKA_LIBRARY AND NOT MISSING_INTERNAL_CPPKAFKA_LIBRARY AND NOT ARCH_ARM)
+elseif (NOT MISSING_INTERNAL_RDKAFKA_LIBRARY AND NOT MISSING_INTERNAL_CPPKAFKA_LIBRARY)
     set (USE_INTERNAL_RDKAFKA_LIBRARY 1)
     set (RDKAFKA_INCLUDE_DIR "${ClickHouse_SOURCE_DIR}/contrib/librdkafka/src")
     set (RDKAFKA_LIBRARY rdkafka)
     set (CPPKAFKA_LIBRARY cppkafka)
     set (USE_RDKAFKA 1)
-elseif(ARCH_ARM)
-    message (${RECONFIGURE_MESSAGE_LEVEL} "Using internal rdkafka on ARM is not supported")
 endif ()
 
 message (STATUS "Using librdkafka=${USE_RDKAFKA}: ${RDKAFKA_INCLUDE_DIR} : ${RDKAFKA_LIBRARY} ${CPPKAFKA_LIBRARY}")

cmake/find/zlib.cmake

@@ -35,6 +35,7 @@ if (NOT ZLIB_FOUND AND NOT MISSING_INTERNAL_ZLIB_LIBRARY)
     set (ZLIB_INCLUDE_DIRECTORIES ${ZLIB_INCLUDE_DIR}) # for protobuf
     set (ZLIB_FOUND 1) # for poco
     set (ZLIB_LIBRARIES zlib CACHE INTERNAL "")
+    set (ZLIB_LIBRARY_NAME ${ZLIB_LIBRARIES}) # for cassandra
     set (ZLIB_NAME "${INTERNAL_ZLIB_NAME}")
 endif ()
 

contrib/aws

@@ -1 +1 @@
-Subproject commit a220591e335923ce1c19bbf9eb925787f7ab6c13
+Subproject commit 7d48b2c8193679cc4516e5bd68ae4a64b94dae7d

contrib/cassandra

@@ -1 +1 @@
-Subproject commit d10187efb25b26da391def077edf3c6f2f3a23dd
+Subproject commit b446d7eb68e6962f431e2b3771313bfe9a2bbd93

contrib/h3

@@ -1 +1 @@
-Subproject commit 6cfd649e8c0d3ed913e8aae928a669fc3b8a2365
+Subproject commit e209086ae1b5477307f545a0f6111780edc59940

contrib/h3-cmake/CMakeLists.txt

@@ -16,6 +16,7 @@ ${H3_SOURCE_DIR}/lib/mathExtensions.c
 ${H3_SOURCE_DIR}/lib/polygon.c
 ${H3_SOURCE_DIR}/lib/vec2d.c
 ${H3_SOURCE_DIR}/lib/vec3d.c
+${H3_SOURCE_DIR}/lib/vertex.c
 ${H3_SOURCE_DIR}/lib/vertexGraph.c
 )
 

contrib/hyperscan

@@ -1 +1 @@
-Subproject commit 3907fd00ee8b2538739768fa9533f8635a276531
+Subproject commit e9f08df0213fc637aac0a5bbde9beeaeba2fe9fa

contrib/libpq

@@ -1 +1 @@
-Subproject commit 8e7e905854714a7fbb49c124dbc45c7bd4b98e07
+Subproject commit 1f9c286dba60809edb64e384d6727d80d269b6cf

contrib/librdkafka-cmake/CMakeLists.txt

@@ -51,11 +51,11 @@ set(SRCS
   ${RDKAFKA_SOURCE_DIR}/rdkafka_roundrobin_assignor.c
   ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl.c
 #  ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_cyrus.c        # optionally included below
-  ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_oauthbearer.c
+#  ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_oauthbearer.c  # optionally included below
   ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_plain.c
-  ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_scram.c
+#  ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_scram.c        # optionally included below
 #  ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_win32.c
-  ${RDKAFKA_SOURCE_DIR}/rdkafka_ssl.c
+#  ${RDKAFKA_SOURCE_DIR}/rdkafka_ssl.c               # optionally included below
   ${RDKAFKA_SOURCE_DIR}/rdkafka_sticky_assignor.c
   ${RDKAFKA_SOURCE_DIR}/rdkafka_subscription.c
   ${RDKAFKA_SOURCE_DIR}/rdkafka_timer.c
@@ -82,10 +82,33 @@ set(SRCS
 
 if(${ENABLE_CYRUS_SASL})
     message (STATUS "librdkafka with SASL support")
-    set(SRCS
+    set(WITH_SASL_CYRUS 1)
-        ${SRCS}
+endif()
-        ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_cyrus.c # needed to support Kerberos, requires cyrus-sasl
+
-    )
+if(OPENSSL_FOUND)
+    message (STATUS "librdkafka with SSL support")
+    set(WITH_SSL 1)
+
+    if(${ENABLE_CYRUS_SASL})
+       set(WITH_SASL_SCRAM 1)
+       set(WITH_SASL_OAUTHBEARER 1)
+    endif()
+endif()
+
+if(WITH_SSL)
+  list(APPEND SRCS ${RDKAFKA_SOURCE_DIR}/rdkafka_ssl.c)
+endif()
+
+if(WITH_SASL_CYRUS)
+  list(APPEND SRCS ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_cyrus.c) # needed to support Kerberos, requires cyrus-sasl
+endif()
+
+if(WITH_SASL_SCRAM)
+  list(APPEND SRCS ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_scram.c)
+endif()
+
+if(WITH_SASL_OAUTHBEARER)
+  list(APPEND SRCS ${RDKAFKA_SOURCE_DIR}/rdkafka_sasl_oauthbearer.c)
 endif()
 
 add_library(rdkafka ${SRCS})
@@ -101,7 +124,6 @@ if(OPENSSL_SSL_LIBRARY AND OPENSSL_CRYPTO_LIBRARY)
 endif()
 if(${ENABLE_CYRUS_SASL})
     target_link_libraries(rdkafka PRIVATE ${CYRUS_SASL_LIBRARY})
-    set(WITH_SASL_CYRUS 1)
 endif()
 
 file(MAKE_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/auxdir)

contrib/librdkafka-cmake/config.h.in

@@ -1,7 +1,6 @@
 // Originally generated by ./configure
 #ifndef _CONFIG_H_
 #define _CONFIG_H_
-#define ARCH "x86_64"
 #define BUILT_WITH "GCC GXX PKGCONFIG OSXLD LIBDL PLUGINS ZLIB SSL SASL_CYRUS ZSTD HDRHISTOGRAM LZ4_EXT SNAPPY SOCKEM SASL_SCRAM CRC32C_HW"
 
 #define CPU "generic"
@@ -60,14 +59,14 @@
 // WITH_SOCKEM
 #define WITH_SOCKEM 1
 // libssl
-#define WITH_SSL 1
+#cmakedefine WITH_SSL 1
 // WITH_SASL_SCRAM
-#define WITH_SASL_SCRAM 1
+#cmakedefine WITH_SASL_SCRAM 1
 // WITH_SASL_OAUTHBEARER
-#define WITH_SASL_OAUTHBEARER 1
+#cmakedefine WITH_SASL_OAUTHBEARER 1
 #cmakedefine WITH_SASL_CYRUS 1
 // crc32chw
-#if !defined(__PPC__)
+#if !defined(__PPC__) && (!defined(__aarch64__) || defined(__ARM_FEATURE_CRC32))
 #define WITH_CRC32C_HW 1
 #endif
 // regex

contrib/libuv

@@ -1 +1 @@
-Subproject commit bc14c44b6269c458f2cc7e09eb300f4b64899903
+Subproject commit e2e9b7e9f978ce8a1367b5fe781d97d1ce9f94ab

contrib/poco

@@ -1 +1 @@
-Subproject commit 2c32e17c7dfee1f8bf24227b697cdef5fddf0823
+Subproject commit e11f3c971570cf6a31006cd21cadf41a259c360a

debian/changelog

@@ -1,5 +1,5 @@
-clickhouse (21.1.0) unstable; urgency=low
+clickhouse (21.3.1.1) unstable; urgency=low
 
   * Modified source code
 
- -- Alexey Milovidov <milovidov@yandex-team.ru>  Mon, 11 Jan 2021 03:51:08 +0300
+ -- clickhouse-release <clickhouse-release@yandex-team.ru>  Mon, 01 Feb 2021 12:50:53 +0300

docker/client/Dockerfile

@@ -1,7 +1,7 @@
 FROM ubuntu:18.04
 
 ARG repository="deb https://repo.clickhouse.tech/deb/stable/ main/"
-ARG version=21.1.0
+ARG version=21.3.1.*
 
 RUN apt-get update \
     && apt-get install --yes --no-install-recommends \

docker/server/Dockerfile

@@ -1,7 +1,7 @@
 FROM ubuntu:20.04
 
 ARG repository="deb https://repo.clickhouse.tech/deb/stable/ main/"
-ARG version=21.1.0
+ARG version=21.3.1.*
 ARG gosu_ver=1.10
 
 # user/group precreated explicitly with fixed uid/gid on purpose.
@@ -10,7 +10,6 @@ ARG gosu_ver=1.10
 # We do that in advance at the begining of Dockerfile before any packages will be
 # installed to prevent picking those uid / gid by some unrelated software.
 # The same uid / gid (101) is used both for alpine and ubuntu.
-# Number 101 is used by default in openshift
 
 RUN groupadd -r clickhouse --gid=101 \
     && useradd -r -g clickhouse --uid=101 --home-dir=/var/lib/clickhouse --shell=/bin/bash clickhouse \
@@ -37,7 +36,12 @@ RUN groupadd -r clickhouse --gid=101 \
         /var/lib/apt/lists/* \
         /var/cache/debconf \
         /tmp/* \
-    && apt-get clean
+    && apt-get clean \
+    && mkdir -p /var/lib/clickhouse /var/log/clickhouse-server /etc/clickhouse-server /etc/clickhouse-client \
+    && chmod ugo+Xrw -R /var/lib/clickhouse /var/log/clickhouse-server /etc/clickhouse-server /etc/clickhouse-client
+
+# we need to allow "others" access to clickhouse folder, because docker container
+# can be started with arbitrary uid (openshift usecase)
 
 ADD https://github.com/tianon/gosu/releases/download/$gosu_ver/gosu-amd64 /bin/gosu
 

docker/server/Dockerfile.alpine

@@ -14,16 +14,18 @@ COPY alpine-root/ /
 # We do that in advance at the begining of Dockerfile before any packages will be
 # installed to prevent picking those uid / gid by some unrelated software.
 # The same uid / gid (101) is used both for alpine and ubuntu.
-# Number 101 is used by default in openshift
 
 RUN addgroup -S -g 101 clickhouse \
     && adduser -S -h /var/lib/clickhouse -s /bin/bash -G clickhouse -g "ClickHouse server" -u 101 clickhouse \
+    && mkdir -p /var/lib/clickhouse /var/log/clickhouse-server /etc/clickhouse-server /etc/clickhouse-client \
     && chown clickhouse:clickhouse /var/lib/clickhouse \
-    && chmod 700 /var/lib/clickhouse \
     && chown root:clickhouse /var/log/clickhouse-server \
-    && chmod 775 /var/log/clickhouse-server \
     && chmod +x /entrypoint.sh \
-    && apk add --no-cache su-exec bash
+    && apk add --no-cache su-exec bash \
+    && chmod ugo+Xrw -R /var/lib/clickhouse /var/log/clickhouse-server /etc/clickhouse-server /etc/clickhouse-client
+
+# we need to allow "others" access to clickhouse folder, because docker container
+# can be started with arbitrary uid (openshift usecase)
 
 EXPOSE 9000 8123 9009
 

docker/test/Dockerfile

@@ -1,7 +1,7 @@
 FROM ubuntu:18.04
 
 ARG repository="deb https://repo.clickhouse.tech/deb/stable/ main/"
-ARG version=21.1.0
+ARG version=21.3.1.*
 
 RUN apt-get update && \
     apt-get install -y apt-transport-https dirmngr && \

docker/test/fasttest/Dockerfile

@@ -43,6 +43,7 @@ RUN apt-get update \
         clang-tidy-${LLVM_VERSION} \
         cmake \
         curl \
+        lsof \
         expect \
         fakeroot \
         git \

docker/test/fasttest/run.sh

@@ -251,8 +251,12 @@ function run_tests
         00701_rollup
         00834_cancel_http_readonly_queries_on_client_close
         00911_tautological_compare
+
+        # Hyperscan
         00926_multimatch
         00929_multi_match_edit_distance
+        01681_hyperscan_debug_assertion
+
         01031_mutations_interpreter_and_context
         01053_ssd_dictionary # this test mistakenly requires acces to /var/lib/clickhouse -- can't run this locally, disabled
         01083_expressions_in_engine_arguments
@@ -269,6 +273,8 @@ function run_tests
         01281_group_by_limit_memory_tracking    # max_memory_usage_for_user can interfere another queries running concurrently
         01318_encrypt                           # Depends on OpenSSL
         01318_decrypt                           # Depends on OpenSSL
+        01663_aes_msan                          # Depends on OpenSSL
+        01667_aes_args_check                    # Depends on OpenSSL
         01281_unsucceeded_insert_select_queries_counter
         01292_create_user
         01294_lazy_database_concurrent
@@ -330,9 +336,12 @@ function run_tests
         # nc - command not found
         01601_proxy_protocol
         01622_defaults_for_url_engine
+
+        # JSON functions
+        01666_blns
     )
 
-    time clickhouse-test -j 8 --order=random --no-long --testname --shard --zookeeper --skip "${TESTS_TO_SKIP[@]}" -- "$FASTTEST_FOCUS" 2>&1 | ts '%Y-%m-%d %H:%M:%S' | tee "$FASTTEST_OUTPUT/test_log.txt"
+    time clickhouse-test --hung-check -j 8 --order=random --use-skip-list --no-long --testname --shard --zookeeper --skip "${TESTS_TO_SKIP[@]}" -- "$FASTTEST_FOCUS" 2>&1 | ts '%Y-%m-%d %H:%M:%S' | tee "$FASTTEST_OUTPUT/test_log.txt"
 
     # substr is to remove semicolon after test name
     readarray -t FAILED_TESTS < <(awk '/\[ FAIL|TIMEOUT|ERROR \]/ { print substr($3, 1, length($3)-1) }' "$FASTTEST_OUTPUT/test_log.txt" | tee "$FASTTEST_OUTPUT/failed-parallel-tests.txt")
@@ -355,7 +364,7 @@ function run_tests
 
         echo "Going to run again: ${FAILED_TESTS[*]}"
 
-        clickhouse-test --order=random --no-long --testname --shard --zookeeper "${FAILED_TESTS[@]}" 2>&1 | ts '%Y-%m-%d %H:%M:%S' | tee -a "$FASTTEST_OUTPUT/test_log.txt"
+        clickhouse-test --hung-check --order=random --no-long --testname --shard --zookeeper "${FAILED_TESTS[@]}" 2>&1 | ts '%Y-%m-%d %H:%M:%S' | tee -a "$FASTTEST_OUTPUT/test_log.txt"
     else
         echo "No failed tests"
     fi

docker/test/fuzzer/query-fuzzer-tweaks-users.xml

@@ -11,6 +11,10 @@
                     <max>10</max>
                 </max_execution_time>
 
+                <max_memory_usage>
+                    <max>10G</max>
+                </max_memory_usage>
+
                 <!-- Not ready for production -->
                 <compile_expressions>
                     <readonly />

docker/test/fuzzer/run-fuzzer.sh

@@ -21,13 +21,16 @@ function clone
 
     git init
     git remote add origin https://github.com/ClickHouse/ClickHouse
-    git fetch --depth=1 origin "$SHA_TO_TEST"
+
-    git fetch --depth=1 origin master # Used to obtain the list of modified or added tests
+    # Network is unreliable. GitHub neither.
+    for _ in {1..100}; do git fetch --depth=100 origin "$SHA_TO_TEST" && break; sleep 1; done
+    # Used to obtain the list of modified or added tests
+    for _ in {1..100}; do git fetch --depth=100 origin master && break; sleep 1; done
 
     # If not master, try to fetch pull/.../{head,merge}
     if [ "$PR_TO_TEST" != "0" ]
     then
-        git fetch --depth=1 origin "refs/pull/$PR_TO_TEST/*:refs/heads/pull/$PR_TO_TEST/*"
+        for _ in {1..100}; do git fetch --depth=100 origin "refs/pull/$PR_TO_TEST/*:refs/heads/pull/$PR_TO_TEST/*" && break; sleep 1; done
     fi
 
     git checkout "$SHA_TO_TEST"
@@ -75,7 +78,7 @@ function fuzz
 {
     # Obtain the list of newly added tests. They will be fuzzed in more extreme way than other tests.
     cd ch
-    NEW_TESTS=$(git diff --name-only master "$SHA_TO_TEST" | grep -P 'tests/queries/0_stateless/.*\.sql' | sed -r -e 's!^!ch/!' | sort -R)
+    NEW_TESTS=$(git diff --name-only "$(git merge-base origin/master "$SHA_TO_TEST"~)" "$SHA_TO_TEST" | grep -P 'tests/queries/0_stateless/.*\.sql' | sed -r -e 's!^!ch/!' | sort -R)
     cd ..
     if [[ -n "$NEW_TESTS" ]]
     then
@@ -85,6 +88,7 @@ function fuzz
     fi
 
     ./clickhouse-server --config-file db/config.xml -- --path db 2>&1 | tail -100000 > server.log &
+
     server_pid=$!
     kill -0 $server_pid
     while ! ./clickhouse-client --query "select 1" && kill -0 $server_pid ; do echo . ; sleep 1 ; done
@@ -92,6 +96,17 @@ function fuzz
     kill -0 $server_pid
     echo Server started
 
+    echo "
+handle all noprint
+handle SIGSEGV stop print
+handle SIGBUS stop print
+continue
+thread apply all backtrace
+continue
+" > script.gdb
+
+    gdb -batch -command script.gdb -p "$(pidof clickhouse-server)" &
+
     fuzzer_exit_code=0
     # SC2012: Use find instead of ls to better handle non-alphanumeric filenames. They are all alphanumeric.
     # SC2046: Quote this to prevent word splitting. Actually I need word splitting.
@@ -175,16 +190,16 @@ case "$stage" in
         # Lost connection to the server. This probably means that the server died
         # with abort.
         echo "failure" > status.txt
-        if ! grep -ao "Received signal.*\|Logical error.*\|Assertion.*failed\|Failed assertion.*\|.*runtime error: .*\|.*is located.*" server.log > description.txt
+        if ! grep -ao "Received signal.*\|Logical error.*\|Assertion.*failed\|Failed assertion.*\|.*runtime error: .*\|.*is located.*\|SUMMARY: MemorySanitizer:.*\|SUMMARY: ThreadSanitizer:.*" server.log > description.txt
         then
-            echo "Lost connection to server. See the logs" > description.txt
+            echo "Lost connection to server. See the logs." > description.txt
         fi
     else
         # Something different -- maybe the fuzzer itself died? Don't grep the
         # server log in this case, because we will find a message about normal
         # server termination (Received signal 15), which is confusing.
         echo "failure" > status.txt
-        echo "Fuzzer failed ($fuzzer_exit_code). See the logs" > description.txt
+        echo "Fuzzer failed ($fuzzer_exit_code). See the logs." > description.txt
     fi
     ;&
 "report")

docker/test/integration/runner/Dockerfile

@@ -62,6 +62,7 @@ RUN python3 -m pip install \
     avro \
     cassandra-driver \
     confluent-kafka \
+    dict2xml \
     dicttoxml \
     docker \
     docker-compose==1.22.0 \

docker/test/performance-comparison/perf.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python3
+#!/usr/bin/env python3
 
 import argparse
 import clickhouse_driver

docker/test/sqlancer/run.sh

@@ -14,12 +14,12 @@ cd /sqlancer/sqlancer-master
 export TIMEOUT=60
 export NUM_QUERIES=1000
 
-( java -jar target/SQLancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPWhere | tee /test_output/TLPWhere.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPWhere.err
+( java -jar target/sqlancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPWhere | tee /test_output/TLPWhere.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPWhere.err
-( java -jar target/SQLancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPGroupBy | tee /test_output/TLPGroupBy.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPGroupBy.err
+( java -jar target/sqlancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPGroupBy | tee /test_output/TLPGroupBy.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPGroupBy.err
-( java -jar target/SQLancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPHaving | tee /test_output/TLPHaving.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPHaving.err
+( java -jar target/sqlancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPHaving | tee /test_output/TLPHaving.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPHaving.err
-( java -jar target/SQLancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPWhere --oracle TLPGroupBy | tee /test_output/TLPWhereGroupBy.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPWhereGroupBy.err
+( java -jar target/sqlancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPWhere --oracle TLPGroupBy | tee /test_output/TLPWhereGroupBy.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPWhereGroupBy.err
-( java -jar target/SQLancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPDistinct | tee /test_output/TLPDistinct.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPDistinct.err
+( java -jar target/sqlancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPDistinct | tee /test_output/TLPDistinct.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPDistinct.err
-( java -jar target/SQLancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPAggregate | tee /test_output/TLPAggregate.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPAggregate.err
+( java -jar target/sqlancer-*.jar --num-threads 10 --timeout-seconds $TIMEOUT --num-queries $NUM_QUERIES  --username default --password "" clickhouse --oracle TLPAggregate | tee /test_output/TLPAggregate.out )  3>&1 1>&2 2>&3 | tee /test_output/TLPAggregate.err
 
 service clickhouse-server stop && sleep 10
 

docker/test/stateless/run.sh

@@ -53,14 +53,15 @@ function run_tests()
     if [ "$NUM_TRIES" -gt "1" ]; then
         ADDITIONAL_OPTIONS+=('--skip')
         ADDITIONAL_OPTIONS+=('00000_no_tests_to_skip')
+        ADDITIONAL_OPTIONS+=('--jobs')
+        ADDITIONAL_OPTIONS+=('4')
     fi
 
-    for _ in $(seq 1 "$NUM_TRIES"); do
+    clickhouse-test --testname --shard --zookeeper --hung-check --print-time \
-        clickhouse-test --testname --shard --zookeeper --hung-check --print-time "$SKIP_LIST_OPT" "${ADDITIONAL_OPTIONS[@]}" 2>&1 | ts '%Y-%m-%d %H:%M:%S' | tee -a test_output/test_result.txt
+            --test-runs "$NUM_TRIES" \
-        if [ "${PIPESTATUS[0]}" -ne "0" ]; then
+            "$SKIP_LIST_OPT" "${ADDITIONAL_OPTIONS[@]}" 2>&1 \
-            break;
+        | ts '%Y-%m-%d %H:%M:%S' \
-        fi
+        | tee -a test_output/test_result.txt
-    done
 }
 
 export -f run_tests

docker/test/style/Dockerfile

@@ -1,12 +1,16 @@
 # docker build -t yandex/clickhouse-style-test .
 FROM ubuntu:20.04
 
-RUN apt-get update && env DEBIAN_FRONTEND=noninteractive apt-get install --yes shellcheck libxml2-utils git python3-pip && pip3 install codespell
+RUN apt-get update && env DEBIAN_FRONTEND=noninteractive apt-get install --yes shellcheck libxml2-utils git python3-pip pylint && pip3 install codespell
 
 
+# For |& syntax
+SHELL ["bash", "-c"]
+
 CMD cd /ClickHouse/utils/check-style && \
-    ./check-style -n | tee /test_output/style_output.txt && \
+    ./check-style -n              |& tee /test_output/style_output.txt && \
-    ./check-typos | tee /test_output/typos_output.txt && \
+    ./check-typos                 |& tee /test_output/typos_output.txt && \
-    ./check-whitespaces -n | tee /test_output/whitespaces_output.txt && \
+    ./check-whitespaces -n        |& tee /test_output/whitespaces_output.txt && \
-    ./check-duplicate-includes.sh | tee /test_output/duplicate_output.txt && \
+    ./check-duplicate-includes.sh |& tee /test_output/duplicate_output.txt && \
-    ./shellcheck-run.sh | tee /test_output/shellcheck_output.txt
+    ./shellcheck-run.sh           |& tee /test_output/shellcheck_output.txt && \
+    true

docs/en/development/build-osx.md

@@ -16,7 +16,7 @@ $ /usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/inst
 ## Install Required Compilers, Tools, and Libraries {#install-required-compilers-tools-and-libraries}
 
 ``` bash
-$ brew install cmake ninja libtool gettext
+$ brew install cmake ninja libtool gettext llvm
 ```
 
 ## Checkout ClickHouse Sources {#checkout-clickhouse-sources}
@@ -40,7 +40,7 @@ $ cd ClickHouse
 ``` bash
 $ mkdir build
 $ cd build
-$ cmake ..-DCMAKE_C_COMPILER=`brew --prefix llvm`/bin/clang -DCMAKE_CXX_COMPILER=`brew --prefix llvm`/bin/clang++ -DCMAKE_PREFIX_PATH=`brew --prefix llvm`
+$ cmake .. -DCMAKE_C_COMPILER=`brew --prefix llvm`/bin/clang -DCMAKE_CXX_COMPILER=`brew --prefix llvm`/bin/clang++ -DCMAKE_PREFIX_PATH=`brew --prefix llvm`
 $ ninja
 $ cd ..
 ```

docs/en/engines/database-engines/atomic.md

@@ -0,0 +1,17 @@
+---
+toc_priority: 32
+toc_title: Atomic
+---
+
+
+# Atomic {#atomic}
+
+It is supports non-blocking `DROP` and `RENAME TABLE` queries and atomic `EXCHANGE TABLES t1 AND t2` queries. Atomic database engine is used by default.
+
+## Creating a Database {#creating-a-database}
+
+```sql
+CREATE DATABASE test ENGINE = Atomic;
+```
+
+[Original article](https://clickhouse.tech/docs/en/engines/database_engines/atomic/) <!--hide-->

docs/en/engines/database-engines/index.md

@@ -8,14 +8,14 @@ toc_title: Introduction
 
 Database engines allow you to work with tables.
 
-By default, ClickHouse uses its native database engine, which provides configurable [table engines](../../engines/table-engines/index.md) and an [SQL dialect](../../sql-reference/syntax.md).
+By default, ClickHouse uses database engine [Atomic](../../engines/database-engines/atomic.md). It is provides configurable [table engines](../../engines/table-engines/index.md) and an [SQL dialect](../../sql-reference/syntax.md).
 
 You can also use the following database engines:
 
 -   [MySQL](../../engines/database-engines/mysql.md)
 
--   [Lazy](../../engines/database-engines/lazy.md)
-
 -   [MaterializeMySQL](../../engines/database-engines/materialize-mysql.md)
 
+-   [Lazy](../../engines/database-engines/lazy.md)
+
 [Original article](https://clickhouse.tech/docs/en/database_engines/) <!--hide-->

docs/en/engines/database-engines/materialize-mysql.md

@@ -5,9 +5,11 @@ toc_title: MaterializeMySQL
 
 # MaterializeMySQL {#materialize-mysql}
 
- Creates ClickHouse database with all the tables existing in MySQL, and all the data in those tables. 
+Creates ClickHouse database with all the tables existing in MySQL, and all the data in those tables.
 
- ClickHouse server works as MySQL replica. It reads binlog and performs DDL and DML queries.   
+ClickHouse server works as MySQL replica. It reads binlog and performs DDL and DML queries.
+
+This feature is experimental.
 
 ## Creating a Database {#creating-a-database}
 
@@ -25,10 +27,10 @@ ENGINE = MaterializeMySQL('host:port', ['database' | database], 'user', 'passwor
 
 ## Virtual columns {#virtual-columns}
 
- When working with the `MaterializeMySQL` database engine, [ReplacingMergeTree](../../engines/table-engines/mergetree-family/replacingmergetree.md) tables are used with virtual `_sign` and `_version` columns.
+When working with the `MaterializeMySQL` database engine, [ReplacingMergeTree](../../engines/table-engines/mergetree-family/replacingmergetree.md) tables are used with virtual `_sign` and `_version` columns.
  
- - `_version` — Transaction counter. Type [UInt64](../../sql-reference/data-types/int-uint.md). 
+- `_version` — Transaction counter. Type [UInt64](../../sql-reference/data-types/int-uint.md).
- - `_sign` — Deletion mark. Type [Int8](../../sql-reference/data-types/int-uint.md). Possible values: 
+- `_sign` — Deletion mark. Type [Int8](../../sql-reference/data-types/int-uint.md). Possible values:
     - `1` — Row is not deleted, 
     - `-1` — Row is deleted.
 
@@ -63,7 +65,7 @@ MySQL DDL queries are converted into the corresponding ClickHouse DDL queries ([
 
 ### Data Replication {#data-replication}
 
-MaterializeMySQL does not support direct `INSERT`, `DELETE` and `UPDATE` queries. However, they are supported in terms of data replication:
+`MaterializeMySQL` does not support direct `INSERT`, `DELETE` and `UPDATE` queries. However, they are supported in terms of data replication:
 
 - MySQL `INSERT` query is converted into `INSERT` with `_sign=1`.
 
@@ -73,11 +75,11 @@ MaterializeMySQL does not support direct `INSERT`, `DELETE` and `UPDATE` queries
 
 ### Selecting from MaterializeMySQL Tables {#select}
 
-`SELECT` query form MaterializeMySQL tables has some specifics:
+`SELECT` query from `MaterializeMySQL` tables has some specifics:
 
 - If `_version` is not specified in the `SELECT` query, [FINAL](../../sql-reference/statements/select/from.md#select-from-final) modifier is used. So only rows with `MAX(_version)` are selected.
 
-- If `_sign` is not specified in the `SELECT` query, `WHERE _sign=1` is used by default, so the deleted rows are not included into the result set. 
+- If `_sign` is not specified in the `SELECT` query, `WHERE _sign=1` is used by default. So the deleted rows are not included into the result set.
 
 ### Index Conversion {#index-conversion}
 
@@ -85,12 +87,12 @@ MySQL `PRIMARY KEY` and `INDEX` clauses are converted into `ORDER BY` tuples in
 
 ClickHouse has only one physical order, which is determined by `ORDER BY` clause. To create a new physical order, use [materialized views](../../sql-reference/statements/create/view.md#materialized).
 
- **Notes**
+**Notes**
 
- - Rows with `_sign=-1` are not deleted physically from the tables. 
+- Rows with `_sign=-1` are not deleted physically from the tables.
- - Cascade `UPDATE/DELETE` queries are not supported by the `MaterializeMySQL` engine.
+- Cascade `UPDATE/DELETE` queries are not supported by the `MaterializeMySQL` engine.
- - Replication can be easily broken.
+- Replication can be easily broken.
- - Manual operations on database and tables are forbidden.
+- Manual operations on database and tables are forbidden.
 
 ## Examples of Use {#examples-of-use}
 
@@ -105,6 +107,7 @@ mysql> ALTER TABLE db.test ADD COLUMN c VARCHAR(16);
 mysql> UPDATE db.test SET c='Wow!', b=222;
 mysql> SELECT * FROM test;
 ```
+
 ```text
 +---+------+------+ 
 | a |    b |    c |

docs/en/engines/database-engines/mysql.md

@@ -51,6 +51,23 @@ All other MySQL data types are converted into [String](../../sql-reference/data-
 
 [Nullable](../../sql-reference/data-types/nullable.md) is supported.
 
+## Global Variables Support {#global-variables-support}
+
+For better compatibility you may address global variables in MySQL style, as `@@identifier`. 
+
+These variables are supported:
+- `version`
+- `max_allowed_packet`
+
+!!! warning "Warning"
+    By now these variables are stubs and don't correspond to anything.
+
+Example:
+
+``` sql
+SELECT @@version;
+```
+
 ## Examples of Use {#examples-of-use}
 
 Table in MySQL:

docs/en/engines/table-engines/integrations/embedded-rocksdb.md

@@ -7,8 +7,6 @@ toc_title: EmbeddedRocksDB
 
 This engine allows integrating ClickHouse with [rocksdb](http://rocksdb.org/).
 
-`EmbeddedRocksDB` lets you:
-
 ## Creating a Table {#table_engine-EmbeddedRocksDB-creating-a-table}
 
 ``` sql
@@ -23,6 +21,9 @@ CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]
 Required parameters:
 
 -  `primary_key_name` – any column name in the column list.
+- `primary key` must be specified, it supports only one column in the primary key. The primary key will be serialized in binary as a `rocksdb key`.
+- columns other than the primary key will be serialized in binary as `rocksdb` value in corresponding order.
+- queries with key `equals` or `in` filtering will be optimized to multi keys lookup from `rocksdb`.
 
 Example:
 
@@ -38,8 +39,4 @@ ENGINE = EmbeddedRocksDB
 PRIMARY KEY key
 ```
 
-## Description {#description}
+[Original article](https://clickhouse.tech/docs/en/operations/table_engines/embedded-rocksdb/) <!--hide-->
-
-- `primary key` must be specified, it only supports one column in primary key. The primary key will serialized in binary as rocksdb key.
-- columns other than the primary key will be serialized in binary as rocksdb value in corresponding order.
-- queries with key `equals` or `in` filtering will be optimized to multi keys lookup from rocksdb.

docs/en/engines/table-engines/integrations/s3.md

@@ -114,6 +114,10 @@ CREATE TABLE big_table (name String, value UInt32) ENGINE = S3('https://storage.
 -   `_path` — Path to the file.
 -   `_file` — Name of the file.
 
+**See Also**
+
+-   [Virtual columns](../../../engines/table-engines/index.md#table_engines-virtual_columns)
+
 ## S3-related settings {#settings}
 
 The following settings can be set before query execution or placed into configuration file.
@@ -124,8 +128,29 @@ The following settings can be set before query execution or placed into configur
 
 Security consideration: if malicious user can specify arbitrary S3 URLs, `s3_max_redirects` must be set to zero to avoid [SSRF](https://en.wikipedia.org/wiki/Server-side_request_forgery) attacks; or alternatively, `remote_host_filter` must be specified in server configuration.
 
-**See Also**
+### Endpoint-based settings {#endpointsettings}
 
--   [Virtual columns](../../../engines/table-engines/index.md#table_engines-virtual_columns)
+The following settings can be specified in configuration file for given endpoint (which will be matched by exact prefix of a URL):
+
+-   `endpoint` — Mandatory. Specifies prefix of an endpoint.
+-   `access_key_id` and `secret_access_key` — Optional. Specifies credentials to use with given endpoint.
+-   `use_environment_credentials` — Optional, default value is `false`. If set to `true`, S3 client will try to obtain credentials from environment variables and Amazon EC2 metadata for given endpoint.
+-   `header` — Optional, can be speficied multiple times. Adds specified HTTP header to a request to given endpoint.
+
+This configuration also applies to S3 disks in `MergeTree` table engine family.
+
+Example:
+
+```
+<s3>
+    <endpoint-name>
+        <endpoint>https://storage.yandexcloud.net/my-test-bucket-768/</endpoint>
+        <!-- <access_key_id>ACCESS_KEY_ID</access_key_id> -->
+        <!-- <secret_access_key>SECRET_ACCESS_KEY</secret_access_key> -->
+        <!-- <use_environment_credentials>false</use_environment_credentials> -->
+        <!-- <header>Authorization: Bearer SOME-TOKEN</header> -->
+    </endpoint-name>
+</s3>
+```
 
 [Original article](https://clickhouse.tech/docs/en/operations/table_engines/s3/) <!--hide-->

docs/en/engines/table-engines/mergetree-family/mergetree.md

@@ -45,7 +45,10 @@ ORDER BY expr
 [PARTITION BY expr]
 [PRIMARY KEY expr]
 [SAMPLE BY expr]
-[TTL expr [DELETE|TO DISK 'xxx'|TO VOLUME 'xxx'], ...]
+[TTL expr 
+    [DELETE|TO DISK 'xxx'|TO VOLUME 'xxx' [, ...] ]
+    [WHERE conditions] 
+    [GROUP BY key_expr [SET v1 = aggr_func(v1) [, v2 = aggr_func(v2) ...]] ] ] 
 [SETTINGS name=value, ...]
 ```
 
@@ -80,7 +83,7 @@ For a description of parameters, see the [CREATE query description](../../../sql
     Expression must have one `Date` or `DateTime` column as a result. Example:
     `TTL date + INTERVAL 1 DAY`
 
-    Type of the rule `DELETE|TO DISK 'xxx'|TO VOLUME 'xxx'` specifies an action to be done with the part if the expression is satisfied (reaches current time): removal of expired rows, moving a part (if expression is satisfied for all rows in a part) to specified disk (`TO DISK 'xxx'`) or to volume (`TO VOLUME 'xxx'`). Default type of the rule is removal (`DELETE`). List of multiple rules can specified, but there should be no more than one `DELETE` rule.
+    Type of the rule `DELETE|TO DISK 'xxx'|TO VOLUME 'xxx'|GROUP BY` specifies an action to be done with the part if the expression is satisfied (reaches current time): removal of expired rows, moving a part (if expression is satisfied for all rows in a part) to specified disk (`TO DISK 'xxx'`) or to volume (`TO VOLUME 'xxx'`), or aggregating values in expired rows. Default type of the rule is removal (`DELETE`). List of multiple rules can specified, but there should be no more than one `DELETE` rule.
 
     For more details, see [TTL for columns and tables](#table_engine-mergetree-ttl)
 
@@ -455,18 +458,28 @@ ALTER TABLE example_table
 Table can have an expression for removal of expired rows, and multiple expressions for automatic move of parts between [disks or volumes](#table_engine-mergetree-multiple-volumes). When rows in the table expire, ClickHouse deletes all corresponding rows. For parts moving feature, all rows of a part must satisfy the movement expression criteria.
 
 ``` sql
-TTL expr [DELETE|TO DISK 'aaa'|TO VOLUME 'bbb'], ...
+TTL expr 
+    [DELETE|TO DISK 'xxx'|TO VOLUME 'xxx'][, DELETE|TO DISK 'aaa'|TO VOLUME 'bbb'] ...
+    [WHERE conditions] 
+    [GROUP BY key_expr [SET v1 = aggr_func(v1) [, v2 = aggr_func(v2) ...]] ]   
 ```
 
 Type of TTL rule may follow each TTL expression. It affects an action which is to be done once the expression is satisfied (reaches current time):
 
 -   `DELETE` - delete expired rows (default action);
 -   `TO DISK 'aaa'` - move part to the disk `aaa`;
--   `TO VOLUME 'bbb'` - move part to the disk `bbb`.
+-   `TO VOLUME 'bbb'` - move part to the disk `bbb`;
+-   `GROUP BY` - aggregate expired rows.
 
-Examples:
+With `WHERE` clause you may specify which of the expired rows to delete or aggregate (it cannot be applied to moves).
 
-Creating a table with TTL
+`GROUP BY` expression must be a prefix of the table primary key. 
+
+If a column is not part of the `GROUP BY` expression and is not set explicitely in the `SET` clause, in result row it contains an occasional value from the grouped rows (as if aggregate function `any` is applied to it).
+
+**Examples**
+
+Creating a table with TTL:
 
 ``` sql
 CREATE TABLE example_table
@@ -482,13 +495,43 @@ TTL d + INTERVAL 1 MONTH [DELETE],
     d + INTERVAL 2 WEEK TO DISK 'bbb';
 ```
 
-Altering TTL of the table
+Altering TTL of the table:
 
 ``` sql
 ALTER TABLE example_table
     MODIFY TTL d + INTERVAL 1 DAY;
 ```
 
+Creating a table, where the rows are expired after one month. The expired rows where dates are Mondays are deleted:
+
+``` sql
+CREATE TABLE table_with_where
+(
+    d DateTime, 
+    a Int
+)
+ENGINE = MergeTree
+PARTITION BY toYYYYMM(d)
+ORDER BY d
+TTL d + INTERVAL 1 MONTH DELETE WHERE toDayOfWeek(d) = 1;
+```
+
+Creating a table, where expired rows are aggregated. In result rows `x` contains the maximum value accross the grouped rows, `y` — the minimum value, and `d` — any occasional value from grouped rows.
+
+``` sql
+CREATE TABLE table_for_aggregation
+(
+    d DateTime, 
+    k1 Int, 
+    k2 Int, 
+    x Int, 
+    y Int
+)
+ENGINE = MergeTree
+ORDER BY k1, k2
+TTL d + INTERVAL 1 MONTH GROUP BY k1, k2 SET x = max(x), y = min(y);
+```
+
 **Removing Data**
 
 Data with an expired TTL is removed when ClickHouse merges data parts.
@@ -657,6 +700,96 @@ The `default` storage policy implies using only one volume, which consists of on
 
 The number of threads performing background moves of data parts can be changed by [background_move_pool_size](../../../operations/settings/settings.md#background_move_pool_size) setting.
 
+## Using S3 for Data Storage {#table_engine-mergetree-s3}
+
+`MergeTree` family table engines is able to store data to [S3](https://aws.amazon.com/s3/) using a disk with type `s3`.
+
+Configuration markup:
+``` xml
+<storage_configuration>
+    ...
+    <disks>
+        <s3>
+            <type>s3</type>
+            <endpoint>https://storage.yandexcloud.net/my-bucket/root-path/</endpoint>
+            <access_key_id>your_access_key_id</access_key_id>
+            <secret_access_key>your_secret_access_key</secret_access_key>
+            <proxy>
+                <uri>http://proxy1</uri>
+                <uri>http://proxy2</uri>
+            </proxy>
+            <connect_timeout_ms>10000</connect_timeout_ms>
+            <request_timeout_ms>5000</request_timeout_ms>
+            <max_connections>100</max_connections>
+            <retry_attempts>10</retry_attempts>
+            <min_bytes_for_seek>1000</min_bytes_for_seek>
+            <metadata_path>/var/lib/clickhouse/disks/s3/</metadata_path>
+            <cache_enabled>true</cache_enabled>
+            <cache_path>/var/lib/clickhouse/disks/s3/cache/</cache_path>
+            <skip_access_check>false</skip_access_check>
+        </s3>
+    </disks>
+    ...
+</storage_configuration>
+```
+
+Required parameters:
+-   `endpoint` — S3 endpoint url in `path` or `virtual hosted` [styles](https://docs.aws.amazon.com/AmazonS3/latest/dev/VirtualHosting.html). Endpoint url should contain bucket and root path to store data.
+-   `access_key_id` — S3 access key id. 
+-   `secret_access_key` — S3 secret access key.
+
+Optional parameters:    
+-   `use_environment_credentials` — Reads AWS credentials from the Environment variables AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY and AWS_SESSION_TOKEN if they exist. Default value is `false`.
+-   `proxy` — Proxy configuration for S3 endpoint. Each `uri` element inside `proxy` block should contain a proxy URL. 
+-   `connect_timeout_ms` — Socket connect timeout in milliseconds. Default value is `10 seconds`. 
+-   `request_timeout_ms` — Request timeout in milliseconds. Default value is `5 seconds`. 
+-   `max_connections` — S3 connections pool size. Default value is `100`. 
+-   `retry_attempts` — Number of retry attempts in case of failed request. Default value is `10`. 
+-   `min_bytes_for_seek` — Minimal number of bytes to use seek operation instead of sequential read. Default value is `1 Mb`. 
+-   `metadata_path` — Path on local FS to store metadata files for S3. Default value is `/var/lib/clickhouse/disks/<disk_name>/`. 
+-   `cache_enabled` — Allows to cache mark and index files on local FS. Default value is `true`. 
+-   `cache_path` — Path on local FS where to store cached mark and index files. Default value is `/var/lib/clickhouse/disks/<disk_name>/cache/`. 
+-   `skip_access_check` — If true disk access checks will not be performed on disk start-up. Default value is `false`.
+
+
+S3 disk can be configured as `main` or `cold` storage:
+``` xml
+<storage_configuration>
+    ...
+    <disks>
+        <s3>
+            <type>s3</type>
+            <endpoint>https://storage.yandexcloud.net/my-bucket/root-path/</endpoint>
+            <access_key_id>your_access_key_id</access_key_id>
+            <secret_access_key>your_secret_access_key</secret_access_key>
+        </s3>
+    </disks>
+    <policies>
+        <s3_main>
+            <volumes>
+                <main>
+                    <disk>s3</disk>
+                </main>
+            </volumes>
+        </s3_main>
+        <s3_cold>
+            <volumes>
+                <main>
+                    <disk>default</disk>
+                </main>
+                <external>
+                    <disk>s3</disk>
+                </external>
+            </volumes>
+            <move_factor>0.2</move_factor>
+        </s3_cold>
+    </policies>
+    ...
+</storage_configuration>
+```
+
+In case of `cold` option a data can be moved to S3 if local disk free size will be smaller than `move_factor * disk_size` or by TTL move rule. 
+
 ### Details {#details}
 
 In the case of `MergeTree` tables, data is getting to disk in different ways:

docs/en/getting-started/tutorial.md

@@ -254,7 +254,6 @@ ENGINE = MergeTree()
 PARTITION BY toYYYYMM(EventDate)
 ORDER BY (CounterID, EventDate, intHash32(UserID))
 SAMPLE BY intHash32(UserID)
-SETTINGS index_granularity = 8192
 ```
 
 ``` sql
@@ -450,7 +449,6 @@ ENGINE = CollapsingMergeTree(Sign)
 PARTITION BY toYYYYMM(StartDate)
 ORDER BY (CounterID, StartDate, intHash32(UserID), VisitID)
 SAMPLE BY intHash32(UserID)
-SETTINGS index_granularity = 8192
 ```
 
 You can execute those queries using the interactive mode of `clickhouse-client` (just launch it in a terminal without specifying a query in advance) or try some [alternative interface](../interfaces/index.md) if you want.

docs/en/interfaces/formats.md

@@ -515,7 +515,7 @@ Example:
 
 ## JSONAsString {#jsonasstring}
 
-In this format, a single JSON object is interpreted as a single value. If input has several JSON objects (comma separated) they will be interpreted as a sepatate rows.
+In this format, a single JSON object is interpreted as a single value. If the input has several JSON objects (comma separated) they will be interpreted as separate rows.
 
 This format can only be parsed for table with a single field of type [String](../sql-reference/data-types/string.md). The remaining columns must be set to [DEFAULT](../sql-reference/statements/create/table.md#default) or [MATERIALIZED](../sql-reference/statements/create/table.md#materialized), or omitted. Once you collect whole JSON object to string you can use [JSON functions](../sql-reference/functions/json-functions.md) to process it.
 
@@ -526,7 +526,7 @@ Query:
 ``` sql
 DROP TABLE IF EXISTS json_as_string;
 CREATE TABLE json_as_string (json String) ENGINE = Memory;
-INSERT INTO json_as_string FORMAT JSONAsString {"foo":{"bar":{"x":"y"},"baz":1}},{},{"any json stucture":1}
+INSERT INTO json_as_string (json) FORMAT JSONAsString {"foo":{"bar":{"x":"y"},"baz":1}},{},{"any json stucture":1}
 SELECT * FROM json_as_string;
 ```
 
@@ -540,7 +540,6 @@ Result:
 └───────────────────────────────────┘
 ```
 
-
 ## JSONCompact {#jsoncompact}
 ## JSONCompactString {#jsoncompactstring}
 

docs/en/introduction/adopters.md

@@ -9,7 +9,7 @@ toc_title: Adopters
     The following list of companies using ClickHouse and their success stories is assembled from public sources, thus might differ from current reality. We’d appreciate it if you share the story of adopting ClickHouse in your company and [add it to the list](https://github.com/ClickHouse/ClickHouse/edit/master/docs/en/introduction/adopters.md), but please make sure you won’t have any NDA issues by doing so. Providing updates with publications from other companies is also useful.
 
 | Company | Industry | Usecase | Cluster Size | (Un)Compressed Data Size<abbr title="of single replica"><sup>\*</sup></abbr> | Reference |
-|------------------------------------------------------------------------------------------------|---------------------------------|-----------------------|------------------------------------------------------------|------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|---------|----------|---------|--------------|------------------------------------------------------------------------------|-----------|
 | <a href="https://2gis.ru" class="favicon">2gis</a> | Maps | Monitoring | — | — | [Talk in Russian, July 2019](https://youtu.be/58sPkXfq6nw) |
 | <a href="https://getadmiral.com/" class="favicon">Admiral</a> | Martech | Engagement Management | — | — | [Webinar Slides, June 2020](https://altinity.com/presentations/2020/06/16/big-data-in-real-time-how-clickhouse-powers-admirals-visitor-relationships-for-publishers) |
 | <a href="https://cn.aliyun.com/" class="favicon">Alibaba Cloud</a> | Cloud | Managed Service | — | — | [Official Website](https://help.aliyun.com/product/144466.html) |
@@ -120,5 +120,6 @@ toc_title: Adopters
 | <a href="https://htc-cs.ru/" class="favicon">ЦВТ</a> | Software Development | Metrics, Logging | — | — | [Blog Post, March 2019, in Russian](https://vc.ru/dev/62715-kak-my-stroili-monitoring-na-prometheus-clickhouse-i-elk) |
 | <a href="https://mkb.ru/" class="favicon">МКБ</a> | Bank | Web-system monitoring | — | — | [Slides in Russian, September 2019](https://github.com/ClickHouse/clickhouse-presentations/blob/master/meetup28/mkb.pdf) |
 | <a href="https://cft.ru/" class="favicon">ЦФТ</a> | Banking, Financial products, Payments | — | — | — | [Meetup in Russian, April 2020](https://team.cft.ru/events/162) |
+| <a href="https://www.kakaocorp.com/" class="favicon">kakaocorp</a> | Internet company | — | — | — | [if(kakao)2020 conference](https://if.kakao.com/session/117) |
 
 [Original article](https://clickhouse.tech/docs/en/introduction/adopters/) <!--hide-->

docs/en/operations/access-rights.md

@@ -27,6 +27,8 @@ We recommend using SQL-driven workflow. Both of the configuration methods work s
 !!! note "Warning"
     You can’t manage the same access entity by both configuration methods simultaneously.
 
+To see all users, roles, profiles, etc. and all their grants use [SHOW ACCESS](../sql-reference/statements/show.md#show-access-statement) statement.
+
 ## Usage {#access-control-usage}
 
 By default, the ClickHouse server provides the `default` user account which is not allowed using SQL-driven access control and account management but has all the rights and permissions. The `default` user account is used in any cases when the username is not defined, for example, at login from client or in distributed queries. In distributed query processing a default user account is used, if the configuration of the server or cluster doesn’t specify the [user and password](../engines/table-engines/special/distributed.md) properties.

docs/en/operations/caches.md

@@ -0,0 +1,26 @@
+---
+toc_priority: 65
+toc_title: Caches
+---
+
+# Cache Types {#cache-types}
+
+When performing queries, ClichHouse uses different caches.
+
+Main cache types:
+- `mark_cache` — Cache of marks used by table engines of the [MergeTree](../engines/table-engines/mergetree-family/mergetree.md) family.
+- `uncompressed_cache` — Cache of uncompressed data used by table engines of the [MergeTree](../engines/table-engines/mergetree-family/mergetree.md) family.
+
+Additional cache types:
+- DNS cache
+- [regexp](../interfaces/formats.md#data-format-regexp) cache
+- compiled expressions cache
+- [Avro format](../interfaces/formats.md#data-format-avro) schemas cache
+- [dictionaries data cache](../sql-reference/dictionaries/index.md)
+
+Indirectly used:
+- OS page cache
+
+To drop cache, use [SYSTEM DROP ... CACHE](../sql-reference/statements/system.md) statements.
+
+[Original article](https://clickhouse.tech/docs/en/operations/caches/) <!--hide-->

docs/en/operations/settings/settings.md

@@ -428,7 +428,7 @@ Possible values:
 
 -   `'basic'` — Use basic parser.
 
-    ClickHouse can parse only the basic `YYYY-MM-DD HH:MM:SS` or `YYYY-MM-DD` format. For example, `'2019-08-20 10:18:56'` or `2019-08-20`.
+    ClickHouse can parse only the basic `YYYY-MM-DD HH:MM:SS` or `YYYY-MM-DD` format. For example, `2019-08-20 10:18:56` or `2019-08-20`.
 
 Default value: `'basic'`.
 
@@ -443,19 +443,19 @@ Allows choosing different output formats of the text representation of date and
 
 Possible values:
 
--   `'simple'` - Simple output format.
+-   `simple` - Simple output format.
 
-    Clickhouse output date and time `YYYY-MM-DD hh:mm:ss` format. For example, `'2019-08-20 10:18:56'`. Calculation is performed according to the data type's time zone (if present) or server time zone.
+    Clickhouse output date and time `YYYY-MM-DD hh:mm:ss` format. For example, `2019-08-20 10:18:56`. The calculation is performed according to the data type's time zone (if present) or server time zone.
 
--   `'iso'` - ISO output format.
+-   `iso` - ISO output format.
 
-    Clickhouse output date and time in [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) `YYYY-MM-DDThh:mm:ssZ` format. For example, `'2019-08-20T10:18:56Z'`. Note that output is in UTC (`Z` means UTC).
+    Clickhouse output date and time in [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) `YYYY-MM-DDThh:mm:ssZ` format. For example, `2019-08-20T10:18:56Z`. Note that output is in UTC (`Z` means UTC).
 
--   `'unix_timestamp'` - Unix timestamp output format.
+-   `unix_timestamp` - Unix timestamp output format.
 
-    Clickhouse output date and time in [Unix timestamp](https://en.wikipedia.org/wiki/Unix_time) format. For example `'1566285536'`.
+    Clickhouse output date and time in [Unix timestamp](https://en.wikipedia.org/wiki/Unix_time) format. For example `1566285536`.
 
-Default value: `'simple'`.
+Default value: `simple`.
 
 See also:
 
@@ -1944,6 +1944,21 @@ Possible values:
 
 Default value: 16.
 
+## background_message_broker_schedule_pool_size {#background_message_broker_schedule_pool_size}
+
+Sets the number of threads performing background tasks for message streaming. This setting is applied at the ClickHouse server start and can’t be changed in a user session.
+
+Possible values:
+
+-   Any positive integer.
+
+Default value: 16.
+
+**See Also**
+
+-   [Kafka](../../engines/table-engines/integrations/kafka.md#kafka) engine
+-   [RabbitMQ](../../engines/table-engines/integrations/rabbitmq.md#rabbitmq-engine) engine
+
 ## validate_polygons {#validate_polygons}
 
 Enables or disables throwing an exception in the [pointInPolygon](../../sql-reference/functions/geo/index.md#pointinpolygon) function, if the polygon is self-intersecting or self-tangent.
@@ -2489,7 +2504,6 @@ Possible values:
 
 Default value: `0`.
 
-
 ## aggregate_functions_null_for_empty {#aggregate_functions_null_for_empty}
 
 Enables or disables rewriting all aggregate functions in a query, adding [-OrNull](../../sql-reference/aggregate-functions/combinators.md#agg-functions-combinator-ornull) suffix to them. Enable it for SQL standard compatibility.
@@ -2506,11 +2520,7 @@ Default value: 0.
 
 Consider the following query with aggregate functions:
 ```sql
-SELECT
+SELECT SUM(-1), MAX(0) FROM system.one WHERE 0;
-    SUM(-1),
-    MAX(0)
-FROM system.one
-WHERE 0
 ```
 
 With `aggregate_functions_null_for_empty = 0` it would produce:
@@ -2527,7 +2537,6 @@ With `aggregate_functions_null_for_empty = 1` the result would be:
 └───────────────┴──────────────┘
 ```
 
-
 ## union_default_mode {#union-default-mode}
 
 Sets a mode for combining `SELECT` query results. The setting is only used when shared with [UNION](../../sql-reference/statements/select/union.md) without explicitly specifying the `UNION ALL` or `UNION DISTINCT`.
@@ -2542,7 +2551,6 @@ Default value: `''`.
 
 See examples in [UNION](../../sql-reference/statements/select/union.md).
 
-
 ## data_type_default_nullable {#data_type_default_nullable}
 
 Allows data types without explicit modifiers [NULL or NOT NULL](../../sql-reference/statements/create/table.md#null-modifiers) in column definition will be [Nullable](../../sql-reference/data-types/nullable.md#data_type-nullable).
@@ -2554,7 +2562,6 @@ Possible values:
 
 Default value: `0`.
 
-
 ## execute_merges_on_single_replica_time_threshold {#execute-merges-on-single-replica-time-threshold}
 
 Enables special logic to perform merges on replicas.
@@ -2574,4 +2581,15 @@ High values for that threshold may lead to replication delays.
 
 It can be useful when merges are CPU bounded not IO bounded (performing heavy data compression, calculating aggregate functions or default expressions that require a large amount of calculations, or just very high number of tiny merges).
 
+## max_final_threads {#max-final-threads}
+
+Sets the maximum number of parallel threads for the `SELECT` query data read phase with the [FINAL](../../sql-reference/statements/select/from.md#select-from-final) modifier.
+
+Possible values:
+
+-   Positive integer.
+-   0 or 1 — Disabled. `SELECT` queries are executed in a single thread.
+
+Default value: `16`.
+
 [Original article](https://clickhouse.tech/docs/en/operations/settings/settings/) <!-- hide -->

docs/en/operations/system-tables/distributed_ddl_queue.md

@@ -1,22 +1,21 @@
 # system.distributed_ddl_queue {#system_tables-distributed_ddl_queue}
 
-Contains information about distributed ddl queries (ON CLUSTER queries) that were executed on a cluster.
+Contains information about [distributed ddl queries (ON CLUSTER clause)](../../sql-reference/distributed-ddl.md) that were executed on a cluster.
 
 Columns:
 
--   `entry`  ([String](../../sql-reference/data-types/string.md)) - Query id.
+-   `entry` ([String](../../sql-reference/data-types/string.md)) — Query id.
--   `host_name`  ([String](../../sql-reference/data-types/string.md)) - Hostname.
+-   `host_name` ([String](../../sql-reference/data-types/string.md)) — Hostname.
--   `host_address`  ([String](../../sql-reference/data-types/string.md)) - IP address that the Hostname resolves to.
+-   `host_address` ([String](../../sql-reference/data-types/string.md)) — IP address that the Hostname resolves to.
--   `port`  ([UInt16](../../sql-reference/data-types/int-uint.md)) - Host Port.
+-   `port` ([UInt16](../../sql-reference/data-types/int-uint.md)) — Host Port.
--   `status`  ([Enum](../../sql-reference/data-types/enum.md)) - Stats of the query.
+-   `status` ([Enum8](../../sql-reference/data-types/enum.md)) — Status of the query.
--   `cluster`  ([String](../../sql-reference/data-types/string.md)) - Cluster name.
+-   `cluster` ([String](../../sql-reference/data-types/string.md)) — Cluster name.
--   `query`  ([String](../../sql-reference/data-types/string.md)) - Query executed.
+-   `query` ([String](../../sql-reference/data-types/string.md)) — Query executed.
--   `initiator`  ([String](../../sql-reference/data-types/string.md)) - Nod that executed the query.
+-   `initiator` ([String](../../sql-reference/data-types/string.md)) — Node that executed the query.
--   `query_start_time` ([Date](../../sql-reference/data-types/date.md)) — Query start time.
+-   `query_start_time` ([DateTime](../../sql-reference/data-types/datetime.md)) — Query start time.
--   `query_finish_time` ([Date](../../sql-reference/data-types/date.md)) — Query finish time.
+-   `query_finish_time` ([DateTime](../../sql-reference/data-types/datetime.md)) — Query finish time.
--   `query_duration_ms` ([UInt64](../../sql-reference/data-types/datetime64.md)) — Duration of query execution in milliseconds.
+-   `query_duration_ms` ([UInt64](../../sql-reference/data-types/datetime64.md)) — Duration of query execution (in milliseconds).
--   `exception_code`  ([Enum](../../sql-reference/data-types/enum.md)) - Exception code from ZooKeeper.
+-   `exception_code` ([Enum8](../../sql-reference/data-types/enum.md)) — Exception code from [ZooKeeper](../../operations/tips.md#zookeeper).
-
 
 **Example**
 
@@ -62,6 +61,5 @@ exception_code:    ZOK
 2 rows in set. Elapsed: 0.025 sec.
 ```
 
-
 [Original article](https://clickhouse.tech/docs/en/operations/system_tables/distributed_ddl_queuedistributed_ddl_queue.md) <!--hide-->
  

docs/en/operations/system-tables/quotas.md

@@ -7,16 +7,16 @@ Columns:
 - `id` ([UUID](../../sql-reference/data-types/uuid.md)) — Quota ID.
 - `storage`([String](../../sql-reference/data-types/string.md)) — Storage of quotas. Possible value: “users.xml” if a quota configured in the users.xml file, “disk” if a quota configured by an SQL-query.
 - `keys` ([Array](../../sql-reference/data-types/array.md)([Enum8](../../sql-reference/data-types/enum.md))) — Key specifies how the quota should be shared. If two connections use the same quota and key, they share the same amounts of resources. Values:
-- `[]` — All users share the same quota.
+    - `[]` — All users share the same quota.
-- `['user_name']` — Connections with the same user name share the same quota.
+    - `['user_name']` — Connections with the same user name share the same quota.
-- `['ip_address']` — Connections from the same IP share the same quota.
+    - `['ip_address']` — Connections from the same IP share the same quota.
-- `['client_key']` — Connections with the same key share the same quota. A key must be explicitly provided by a client. When using [clickhouse-client](../../interfaces/cli.md), pass a key value in the `--quota-key` parameter, or use the `quota_key` parameter in the client configuration file. When using HTTP interface, use the `X-ClickHouse-Quota` header.
+    - `['client_key']` — Connections with the same key share the same quota. A key must be explicitly provided by a client. When using [clickhouse-client](../../interfaces/cli.md), pass a key value in the `--quota-key` parameter, or use the `quota_key` parameter in the client configuration file. When using HTTP interface, use the `X-ClickHouse-Quota` header.
-- `['user_name', 'client_key']` — Connections with the same `client_key` share the same quota. If a key isn’t provided by a client, the qouta is tracked for `user_name`.
+    - `['user_name', 'client_key']` — Connections with the same `client_key` share the same quota. If a key isn’t provided by a client, the qouta is tracked for `user_name`.
-- `['client_key', 'ip_address']` — Connections with the same `client_key` share the same quota. If a key isn’t provided by a client, the qouta is tracked for `ip_address`.
+    - `['client_key', 'ip_address']` — Connections with the same `client_key` share the same quota. If a key isn’t provided by a client, the qouta is tracked for `ip_address`.
 - `durations` ([Array](../../sql-reference/data-types/array.md)([UInt64](../../sql-reference/data-types/int-uint.md))) — Time interval lengths in seconds.
 - `apply_to_all` ([UInt8](../../sql-reference/data-types/int-uint.md#uint-ranges)) — Logical value. It shows which users the quota is applied to. Values:
-- `0` — The quota applies to users specify in the `apply_to_list`.
+    - `0` — The quota applies to users specify in the `apply_to_list`.
-- `1` — The quota applies to all users except those listed in `apply_to_except`.
+    - `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.
 

docs/en/operations/utilities/clickhouse-benchmark.md

@@ -7,7 +7,7 @@ toc_title: clickhouse-benchmark
 
 Connects to a ClickHouse server and repeatedly sends specified queries.
 
-Syntax:
+**Syntax**
 
 ``` bash
 $ clickhouse-benchmark --query ["single query"] [keys]
@@ -28,35 +28,35 @@ $ clickhouse-benchmark [keys] <<< "single query"
 If you want to send a set of queries, create a text file and place each query on the individual string in this file. For example:
 
 ``` sql
-SELECT * FROM system.numbers LIMIT 10000000
+SELECT * FROM system.numbers LIMIT 10000000;
-SELECT 1
+SELECT 1;
 ```
 
-Then pass this file to a standard input of `clickhouse-benchmark`.
+Then pass this file to a standard input of `clickhouse-benchmark`:
 
 ``` bash
-clickhouse-benchmark [keys] < queries_file
+clickhouse-benchmark [keys] < queries_file;
 ```
 
 ## Keys {#clickhouse-benchmark-keys}
 
--   `--query=WORD` - Query to execute. If this parameter is not passed clickhouse-benchmark will read queries from standard input. 
+-   `--query=QUERY` — Query to execute. If this parameter is not passed, `clickhouse-benchmark` will read queries from standard input. 
 -   `-c N`, `--concurrency=N` — Number of queries that `clickhouse-benchmark` sends simultaneously. Default value: 1.
--   `-d N`, `--delay=N` — Interval in seconds between intermediate reports (set 0 to disable reports). Default value: 1.
+-   `-d N`, `--delay=N` — Interval in seconds between intermediate reports (to disable reports set 0). Default value: 1.
--   `-h WORD`, `--host=WORD` — Server host. Default value: `localhost`. For the [comparison mode](#clickhouse-benchmark-comparison-mode) you can use multiple `-h` keys.
+-   `-h HOST`, `--host=HOST` — Server host. Default value: `localhost`. For the [comparison mode](#clickhouse-benchmark-comparison-mode) you can use multiple `-h` keys.
 -   `-p N`, `--port=N` — Server port. Default value: 9000. For the [comparison mode](#clickhouse-benchmark-comparison-mode) you can use multiple `-p` keys.
 -   `-i N`, `--iterations=N` — Total number of queries. Default value: 0 (repeat forever).
--   `-r`, `--randomize` — Random order of queries execution if there is more then one input query.
+-   `-r`, `--randomize` — Random order of queries execution if there is more than one input query.
--   `-s`, `--secure` — Using TLS connection.
+-   `-s`, `--secure` — Using `TLS` connection.
 -   `-t N`, `--timelimit=N` — Time limit in seconds. `clickhouse-benchmark` stops sending queries when the specified time limit is reached. Default value: 0 (time limit disabled).
--   `--confidence=N` — Level of confidence for T-test. Possible values: 0 (80%), 1 (90%), 2 (95%), 3 (98%), 4 (99%), 5 (99.5%). Default value: 5. In the [comparison mode](#clickhouse-benchmark-comparison-mode) `clickhouse-benchmark` performs the [Independent two-sample Student’s t-test](https://en.wikipedia.org/wiki/Student%27s_t-test#Independent_two-sample_t-test) test to determine whether the two distributions aren’t different with the selected level of confidence.
+-   `--confidence=N` — Level of confidence for T-test. Possible values: 0 (80%), 1 (90%), 2 (95%), 3 (98%), 4 (99%), 5 (99.5%). Default value: 5. In the [comparison mode](#clickhouse-benchmark-comparison-mode) `clickhouse-benchmark` performs the [Independent two-sample Student’s t-test](https://en.wikipedia.org/wiki/Student%27s_t-test#Independent_two-sample_t-test) to determine whether the two distributions aren’t different with the selected level of confidence.
 -   `--cumulative` — Printing cumulative data instead of data per interval.
 -   `--database=DATABASE_NAME` — ClickHouse database name. Default value: `default`.
--   `--json=FILEPATH` — JSON output. When the key is set, `clickhouse-benchmark` outputs a report to the specified JSON-file.
+-   `--json=FILEPATH` — `JSON` output. When the key is set, `clickhouse-benchmark` outputs a report to the specified JSON-file.
 -   `--user=USERNAME` — ClickHouse user name. Default value: `default`.
 -   `--password=PSWD` — ClickHouse user password. Default value: empty string.
 -   `--stacktrace` — Stack traces output. When the key is set, `clickhouse-bencmark` outputs stack traces of exceptions.
--   `--stage=WORD` — Query processing stage at server. ClickHouse stops query processing and returns answer to `clickhouse-benchmark` at the specified stage. Possible values: `complete`, `fetch_columns`, `with_mergeable_state`. Default value: `complete`.
+-   `--stage=WORD` — Query processing stage at server. ClickHouse stops query processing and returns an answer to `clickhouse-benchmark` at the specified stage. Possible values: `complete`, `fetch_columns`, `with_mergeable_state`. Default value: `complete`.
 -   `--help` — Shows the help message.
 
 If you want to apply some [settings](../../operations/settings/index.md) for queries, pass them as a key `--<session setting name>= SETTING_VALUE`. For example, `--max_memory_usage=1048576`.
@@ -96,11 +96,11 @@ In the report you can find:
 
     -   Endpoint of ClickHouse server.
     -   Number of processed queries.
-    -   QPS: QPS: How many queries server performed per second during a period specified in the `--delay` argument.
+    -   QPS: How many queries the server performed per second during a period specified in the `--delay` argument.
-    -   RPS: How many rows server read per second during a period specified in the `--delay` argument.
+    -   RPS: How many rows the server reads per second during a period specified in the `--delay` argument.
-    -   MiB/s: How many mebibytes server read per second during a period specified in the `--delay` argument.
+    -   MiB/s: How many mebibytes the server reads per second during a period specified in the `--delay` argument.
-    -   result RPS: How many rows placed by server to the result of a query per second during a period specified in the `--delay` argument.
+    -   result RPS: How many rows placed by the server to the result of a query per second during a period specified in the `--delay` argument.
-    -   result MiB/s. How many mebibytes placed by server to the result of a query per second during a period specified in the `--delay` argument.
+    -   result MiB/s. How many mebibytes placed by the server to the result of a query per second during a period specified in the `--delay` argument.
 
 -   Percentiles of queries execution time.
 
@@ -159,3 +159,5 @@ localhost:9000, queries 10, QPS: 6.082, RPS: 121959604.568, MiB/s: 930.478, resu
 99.900%     0.172 sec.
 99.990%     0.172 sec.
 ```
+
+[Original article](https://clickhouse.tech/docs/en/operations/utilities/clickhouse-benchmark.md) <!--hide-->

docs/en/operations/utilities/clickhouse-copier.md

@@ -71,8 +71,8 @@ Parameters:
     <remote_servers>
         <source_cluster>
             <!--
-                source cluster & destination clusters accepts exactly the same
+                source cluster & destination clusters accept exactly the same
-                parameters as parameters for usual Distributed table
+                parameters as parameters for the usual Distributed table
                 see https://clickhouse.tech/docs/en/engines/table-engines/special/distributed/
             --> 
             <shard>

docs/en/operations/utilities/clickhouse-local.md

@@ -16,7 +16,7 @@ By default `clickhouse-local` does not have access to data on the same host, but
 !!! warning "Warning"
     It is not recommended to load production server configuration into `clickhouse-local` because data can be damaged in case of human error.
 
-For temporary data, a unique temporary data directory is created by default. If you want to override this behavior, the data directory can be explicitly specified with the `-- --path` option.
+For temporary data, a unique temporary data directory is created by default.
 
 ## Usage {#usage}
 
@@ -32,15 +32,22 @@ Arguments:
 -   `-S`, `--structure` — table structure for input data.
 -   `-if`, `--input-format` — input format, `TSV` by default.
 -   `-f`, `--file` — path to data, `stdin` by default.
--   `-q` `--query` — queries to execute with `;` as delimeter. You must specify either `query` or `queries-file` option.
+-   `-q`, `--query` — queries to execute with `;` as delimeter. You must specify either `query` or `queries-file` option.
--   `-qf` `--queries-file` - file path with queries to execute. You must specify either `query` or `queries-file` option.
+-   `-qf`, `--queries-file` - file path with queries to execute. You must specify either `query` or `queries-file` option.
 -   `-N`, `--table` — table name where to put output data, `table` by default.
 -   `-of`, `--format`, `--output-format` — output format, `TSV` by default.
+-   `-d`, `--database` — default database, `_local` by default.
 -   `--stacktrace` — whether to dump debug output in case of exception.
+-   `--echo` — print query before execution. 
 -   `--verbose` — more details on query execution.
--   `-s` — disables `stderr` logging.
+-   `--logger.console` — Log to console.
--   `--config-file` — path to configuration file in same format as for ClickHouse server, by default the configuration empty.
+-   `--logger.log` — Log file name.
+-   `--logger.level` — Log level.
+-   `--ignore-error` — do not stop processing if a query failed.
+-   `-c`, `--config-file` — path to configuration file in same format as for ClickHouse server, by default the configuration empty.
+-   `--no-system-tables` — do not attach system tables.
 -   `--help` — arguments references for `clickhouse-local`.
+-   `-V`, `--version` — print version information and exit.
 
 Also there are arguments for each ClickHouse configuration variable which are more commonly used instead of `--config-file`.
 

docs/en/sql-reference/aggregate-functions/parametric-functions.md

@@ -241,7 +241,7 @@ windowFunnel(window, [mode])(timestamp, cond1, cond2, ..., condN)
 
 **Parameters**
 
--   `window` — Length of the sliding window in seconds.
+-   `window` — Length of the sliding window. The unit of `window` depends on the timestamp itself and varies. Determined using the expression `timestamp of cond2 <= timestamp of cond1 + window`.
 -   `mode` - It is an optional argument.
     -   `'strict'` - When the `'strict'` is set, the windowFunnel() applies conditions only for the unique values.
 -   `timestamp` — Name of the column containing the timestamp. Data types supported: [Date](../../sql-reference/data-types/date.md), [DateTime](../../sql-reference/data-types/datetime.md#data_type-datetime) and other unsigned integer types (note that even though timestamp supports the `UInt64` type, it’s value can’t exceed the Int64 maximum, which is 2^63 - 1).

docs/en/sql-reference/aggregate-functions/reference/argmax.md

@@ -4,6 +4,28 @@ toc_priority: 106
 
 # argMax {#agg-function-argmax}
 
-Syntax: `argMax(arg, val)`
+Syntax: `argMax(arg, val)` or `argMax(tuple(arg, val))`
 
 Calculates the `arg` value for a maximum `val` value. If there are several different values of `arg` for maximum values of `val`, the first of these values encountered is output.
+
+Tuple version of this function will return the tuple with the maximum `val` value. It is convinient for use with `SimpleAggregateFunction`.
+
+**Example:**
+
+``` text
+┌─user─────┬─salary─┐
+│ director │   5000 │
+│ manager  │   3000 │
+│ worker   │   1000 │
+└──────────┴────────┘
+```
+
+``` sql
+SELECT argMax(user, salary), argMax(tuple(user, salary)) FROM salary
+```
+
+``` text
+┌─argMax(user, salary)─┬─argMax(tuple(user, salary))─┐
+│ director             │ ('director',5000)           │
+└──────────────────────┴─────────────────────────────┘
+```

docs/en/sql-reference/aggregate-functions/reference/argmin.md

@@ -4,10 +4,12 @@ toc_priority: 105
 
 # argMin {#agg-function-argmin}
 
-Syntax: `argMin(arg, val)`
+Syntax: `argMin(arg, val)` or `argMin(tuple(arg, val))`
 
 Calculates the `arg` value for a minimal `val` value. If there are several different values of `arg` for minimal values of `val`, the first of these values encountered is output.
 
+Tuple version of this function will return the tuple with the minimal `val` value. It is convinient for use with `SimpleAggregateFunction`.
+
 **Example:**
 
 ``` text
@@ -19,11 +21,11 @@ Calculates the `arg` value for a minimal `val` value. If there are several diffe
 ```
 
 ``` sql
-SELECT argMin(user, salary) FROM salary
+SELECT argMin(user, salary), argMin(tuple(user, salary)) FROM salary
 ```
 
 ``` text
-┌─argMin(user, salary)─┐
+┌─argMin(user, salary)─┬─argMin(tuple(user, salary))─┐
-│ worker               │
+│ worker               │ ('worker',1000)             │
-└──────────────────────┘
+└──────────────────────┴─────────────────────────────┘
 ```

docs/en/sql-reference/data-types/multiword-types.md

@@ -0,0 +1,29 @@
+---
+toc_priority: 61
+toc_title: Multiword Type Names
+---
+
+# Multiword Types {#multiword-types}
+
+When creating tables, you can use data types with a name consisting of several words. This is implemented for better SQL compatibility.
+
+## Multiword Types Support {#multiword-types-support}
+
+| Multiword types                  | Simple types                                                 |
+|----------------------------------|--------------------------------------------------------------|
+| DOUBLE PRECISION                 | [Float64](../../sql-reference/data-types/float.md)           |
+| CHAR LARGE OBJECT                | [String](../../sql-reference/data-types/string.md)           |
+| CHAR VARYING                     | [String](../../sql-reference/data-types/string.md)           |
+| CHARACTER LARGE OBJECT           | [String](../../sql-reference/data-types/string.md)           |
+| CHARACTER VARYING                | [String](../../sql-reference/data-types/string.md)           |
+| NCHAR LARGE OBJECT               | [String](../../sql-reference/data-types/string.md)           |
+| NCHAR VARYING                    | [String](../../sql-reference/data-types/string.md)           |
+| NATIONAL CHARACTER LARGE OBJECT  | [String](../../sql-reference/data-types/string.md)           |
+| NATIONAL CHARACTER VARYING       | [String](../../sql-reference/data-types/string.md)           |
+| NATIONAL CHAR VARYING            | [String](../../sql-reference/data-types/string.md)           |
+| NATIONAL CHARACTER               | [String](../../sql-reference/data-types/string.md)           |
+| NATIONAL CHAR                    | [String](../../sql-reference/data-types/string.md)           |
+| BINARY LARGE OBJECT              | [String](../../sql-reference/data-types/string.md)           |
+| BINARY VARYING                   | [String](../../sql-reference/data-types/string.md)           |
+
+[Original article](https://clickhouse.tech/docs/en/sql-reference/data-types/multiword-types/) <!--hide-->

docs/en/sql-reference/data-types/simpleaggregatefunction.md

@@ -18,6 +18,8 @@ The following aggregate functions are supported:
 -   [`sumMap`](../../sql-reference/aggregate-functions/reference/summap.md#agg_functions-summap)
 -   [`minMap`](../../sql-reference/aggregate-functions/reference/minmap.md#agg_functions-minmap)
 -   [`maxMap`](../../sql-reference/aggregate-functions/reference/maxmap.md#agg_functions-maxmap)
+-   [`argMin`](../../sql-reference/aggregate-functions/reference/argmin.md)
+-   [`argMax`](../../sql-reference/aggregate-functions/reference/argmax.md)
 
 Values of the `SimpleAggregateFunction(func, Type)` look and stored the same way as `Type`, so you do not need to apply functions with `-Merge`/`-State` suffixes. `SimpleAggregateFunction` has better performance than `AggregateFunction` with same aggregation function.
 

docs/en/sql-reference/functions/encryption-functions.md

@@ -11,7 +11,7 @@ Key length depends on encryption mode. It is 16, 24, and 32 bytes long for `-128
 
 Initialization vector length is always 16 bytes (bytes in excess of 16 are ignored). 
 
-Note that these functions work slowly.
+Note that these functions work slowly until ClickHouse 21.1.
 
 ## encrypt {#encrypt}
 
@@ -41,7 +41,7 @@ encrypt('mode', 'plaintext', 'key' [, iv, aad])
 
 **Returned value**
 
--   Ciphered String. [String](../../sql-reference/data-types/string.md#string).
+-   Ciphertext binary string. [String](../../sql-reference/data-types/string.md#string).
 
 **Examples**
 
@@ -52,57 +52,38 @@ Query:
 ``` sql
 CREATE TABLE encryption_test
 (
-    input String,
+    `comment` String,
-    key String DEFAULT unhex('fb9958e2e897ef3fdb49067b51a24af645b3626eed2f9ea1dc7fd4dd71b7e38f9a68db2a3184f952382c783785f9d77bf923577108a88adaacae5c141b1576b0'),
+    `secret` String
-    iv String DEFAULT unhex('8CA3554377DFF8A369BC50A89780DD85'),
+)
-    key32 String DEFAULT substring(key, 1, 32),
+ENGINE = Memory
-    key24 String DEFAULT substring(key, 1, 24),
-    key16 String DEFAULT substring(key, 1, 16)
-) Engine = Memory;
 ```
 
-Insert this data:
+Insert some data (please avoid storing the keys/ivs in the database as this undermines the whole concept of encryption), also storing 'hints' is unsafe too and used only for illustrative purposes:
 
 Query:
 
 ``` sql
-INSERT INTO encryption_test (input) VALUES (''), ('text'), ('What Is ClickHouse?');
+INSERT INTO encryption_test VALUES('aes-256-cfb128 no IV', encrypt('aes-256-cfb128', 'Secret', '12345678910121314151617181920212')),\
+('aes-256-cfb128 no IV, different key', encrypt('aes-256-cfb128', 'Secret', 'keykeykeykeykeykeykeykeykeykeyke')),\
+('aes-256-cfb128 with IV', encrypt('aes-256-cfb128', 'Secret', '12345678910121314151617181920212', 'iviviviviviviviv')),\
+('aes-256-cbc no IV', encrypt('aes-256-cbc', 'Secret', '12345678910121314151617181920212'));
 ```
 
-Example without `iv`:
-
 Query:
 
 ``` sql
-SELECT 'aes-128-ecb' AS mode, hex(encrypt(mode, input, key16)) FROM encryption_test;
+SELECT comment, hex(secret) FROM encryption_test;
 ```
 
 Result:
 
 ``` text
-┌─mode────────┬─hex(encrypt('aes-128-ecb', input, key16))────────────────────────┐
+┌─comment─────────────────────────────┬─hex(secret)──────────────────────┐
-│ aes-128-ecb │ 4603E6862B0D94BBEC68E0B0DF51D60F                                 │
+│ aes-256-cfb128 no IV                │ B4972BDC4459                     │
-│ aes-128-ecb │ 3004851B86D3F3950672DE7085D27C03                                 │
+│ aes-256-cfb128 no IV, different key │ 2FF57C092DC9                     │
-│ aes-128-ecb │ E807F8C8D40A11F65076361AFC7D8B68D8658C5FAA6457985CAA380F16B3F7E4 │
+│ aes-256-cfb128 with IV              │ 5E6CB398F653                     │
-└─────────────┴──────────────────────────────────────────────────────────────────┘
+│ aes-256-cbc no IV                   │ 1BC0629A92450D9E73A00E7D02CF4142 │
-```
+└─────────────────────────────────────┴──────────────────────────────────┘
-
-Example with `iv`:
-
-Query:
-
-``` sql
-SELECT 'aes-256-ctr' AS mode, hex(encrypt(mode, input, key32, iv)) FROM encryption_test;
-```
-
-Result:
-
-``` text
-┌─mode────────┬─hex(encrypt('aes-256-ctr', input, key32, iv))─┐
-│ aes-256-ctr │                                               │
-│ aes-256-ctr │ 7FB039F7                                      │
-│ aes-256-ctr │ 5CBD20F7ABD3AC41FCAA1A5C0E119E2B325949        │
-└─────────────┴───────────────────────────────────────────────┘
 ```
 
 Example with `-gcm`:
@@ -110,40 +91,26 @@ Example with `-gcm`:
 Query:
 
 ``` sql
-SELECT 'aes-256-gcm' AS mode, hex(encrypt(mode, input, key32, iv)) FROM encryption_test;
+INSERT INTO encryption_test VALUES('aes-256-gcm', encrypt('aes-256-gcm', 'Secret', '12345678910121314151617181920212', 'iviviviviviviviv')), \
+('aes-256-gcm with AAD', encrypt('aes-256-gcm', 'Secret', '12345678910121314151617181920212', 'iviviviviviviviv', 'aad'));
+
+SELECT comment, hex(secret) FROM encryption_test WHERE comment LIKE '%gcm%';
 ```
 
 Result:
 
 ``` text
-┌─mode────────┬─hex(encrypt('aes-256-gcm', input, key32, iv))──────────────────────────┐
+┌─comment──────────────┬─hex(secret)──────────────────────────────────┐
-│ aes-256-gcm │ E99DBEBC01F021758352D7FBD9039EFA                                       │
+│ aes-256-gcm          │ A8A3CCBC6426CFEEB60E4EAE03D3E94204C1B09E0254 │
-│ aes-256-gcm │ 8742CE3A7B0595B281C712600D274CA881F47414                               │
+│ aes-256-gcm with AAD │ A8A3CCBC6426D9A1017A0A932322F1852260A4AD6837 │
-│ aes-256-gcm │ A44FD73ACEB1A64BDE2D03808A2576EDBB60764CC6982DB9AF2C33C893D91B00C60DC5 │
+└──────────────────────┴──────────────────────────────────────────────┘
-└─────────────┴────────────────────────────────────────────────────────────────────────┘
-```
-
-Example with `-gcm` mode and with `aad`:
-
-Query:
-
-``` sql
-SELECT 'aes-192-gcm' AS mode, hex(encrypt(mode, input, key24, iv, 'AAD')) FROM encryption_test;
-```
-
-Result:
-
-``` text
-┌─mode────────┬─hex(encrypt('aes-192-gcm', input, key24, iv, 'AAD'))───────────────────┐
-│ aes-192-gcm │ 04C13E4B1D62481ED22B3644595CB5DB                                       │
-│ aes-192-gcm │ 9A6CF0FD2B329B04EAD18301818F016DF8F77447                               │
-│ aes-192-gcm │ B961E9FD9B940EBAD7ADDA75C9F198A40797A5EA1722D542890CC976E21113BBB8A7AA │
-└─────────────┴────────────────────────────────────────────────────────────────────────┘
 ```
 
 ## aes_encrypt_mysql {#aes_encrypt_mysql}
 
-Compatible with mysql encryption and can be decrypted with [AES_DECRYPT](https://dev.mysql.com/doc/refman/8.0/en/encryption-functions.html#function_aes-decrypt) function.
+Compatible with mysql encryption and resulting ciphertext can be decrypted with [AES_DECRYPT](https://dev.mysql.com/doc/refman/8.0/en/encryption-functions.html#function_aes-decrypt) function.
+
+Will produce same ciphertext as `encrypt` on equal inputs. But when `key` or `iv` are longer than they should normally be, `aes_encrypt_mysql` will stick to what MySQL's `aes_encrypt` does: 'fold' `key` and ignore excess bits of `IV`.
 
 Supported encryption modes:
 
@@ -156,7 +123,7 @@ Supported encryption modes:
 
 **Syntax**
 
-```sql
+``` sql
 aes_encrypt_mysql('mode', 'plaintext', 'key' [, iv])
 ```
 
@@ -164,78 +131,98 @@ aes_encrypt_mysql('mode', 'plaintext', 'key' [, iv])
 
 -   `mode` — Encryption mode. [String](../../sql-reference/data-types/string.md#string).
 -   `plaintext` — Text that needs to be encrypted. [String](../../sql-reference/data-types/string.md#string).
--   `key` — Encryption key. [String](../../sql-reference/data-types/string.md#string).
+-   `key` — Encryption key. If key is longer than required by mode, MySQL-specific key folding is performed. [String](../../sql-reference/data-types/string.md#string).
--   `iv` — Initialization vector. Optinal. [String](../../sql-reference/data-types/string.md#string).
+-   `iv` — Initialization vector. Optinal, only first 16 bytes are taken into account [String](../../sql-reference/data-types/string.md#string).
 
 **Returned value**
 
--   Ciphered String. [String](../../sql-reference/data-types/string.md#string).
+- Ciphertext binary string. [String](../../sql-reference/data-types/string.md#string).
+
 
 **Examples**
 
-Create this table:
+Given equal input `encrypt` and `aes_encrypt_mysql` produce the same ciphertext:
 
 Query:
 
 ``` sql
-CREATE TABLE encryption_test
+SELECT encrypt('aes-256-cfb128', 'Secret', '12345678910121314151617181920212', 'iviviviviviviviv') = aes_encrypt_mysql('aes-256-cfb128', 'Secret', '12345678910121314151617181920212', 'iviviviviviviviv') AS ciphertexts_equal;
-(
-    input String,
-    key String DEFAULT unhex('fb9958e2e897ef3fdb49067b51a24af645b3626eed2f9ea1dc7fd4dd71b7e38f9a68db2a3184f952382c783785f9d77bf923577108a88adaacae5c141b1576b0'),
-    iv String DEFAULT unhex('8CA3554377DFF8A369BC50A89780DD85'),
-    key32 String DEFAULT substring(key, 1, 32),
-    key24 String DEFAULT substring(key, 1, 24),
-    key16 String DEFAULT substring(key, 1, 16)
-) Engine = Memory;
 ```
 
-Insert this data:
+Result:
 
-Query:
+```
-
+┌─ciphertexts_equal─┐
-``` sql
+│                 1 │
-INSERT INTO encryption_test (input) VALUES (''), ('text'), ('What Is ClickHouse?');
+└───────────────────┘
 ```
 
-Example without `iv`:
+
+But `encrypt` fails when `key` or `iv` is longer than expected:
 
 Query:
 
 ``` sql
-SELECT 'aes-128-cbc' AS mode, hex(aes_encrypt_mysql(mode, input, key32)) FROM encryption_test;
+SELECT encrypt('aes-256-cfb128', 'Secret', '123456789101213141516171819202122', 'iviviviviviviviv123');
 ```
 
 Result:
 
 ``` text
-┌─mode────────┬─hex(aes_encrypt_mysql('aes-128-cbc', input, key32))──────────────┐
+Received exception from server (version 21.1.2):
-│ aes-128-cbc │ FEA8CFDE6EE2C6E7A2CC6ADDC9F62C83                                 │
+Code: 36. DB::Exception: Received from localhost:9000. DB::Exception: Invalid key size: 33 expected 32: While processing encrypt('aes-256-cfb128', 'Secret', '123456789101213141516171819202122', 'iviviviviviviviv123'). 
-│ aes-128-cbc │ 78B16CD4BE107660156124C5FEE6454A                                 │
-│ aes-128-cbc │ 67C0B119D96F18E2823968D42871B3D179221B1E7EE642D628341C2B29BA2E18 │
-└─────────────┴──────────────────────────────────────────────────────────────────┘
 ```
 
-Example with `iv`:
+While `aes_encrypt_mysql` produces MySQL-compatitalbe output:
 
 Query:
 
 ``` sql
-SELECT 'aes-256-cfb128' AS mode, hex(aes_encrypt_mysql(mode, input, key32, iv)) FROM encryption_test;
+SELECT hex(aes_encrypt_mysql('aes-256-cfb128', 'Secret', '123456789101213141516171819202122', 'iviviviviviviviv123')) AS ciphertext;
+```
+
+Result:
+
+```text
+┌─ciphertext───┐
+│ 24E9E4966469 │
+└──────────────┘
+```
+
+Notice how supplying even longer `IV` produces the same result
+
+Query:
+
+``` sql
+SELECT hex(aes_encrypt_mysql('aes-256-cfb128', 'Secret', '123456789101213141516171819202122', 'iviviviviviviviv123456')) AS ciphertext
 ```
 
 Result:
 
 ``` text
-┌─mode───────────┬─hex(aes_encrypt_mysql('aes-256-cfb128', input, key32, iv))─┐
+┌─ciphertext───┐
-│ aes-256-cfb128 │                                                            │
+│ 24E9E4966469 │
-│ aes-256-cfb128 │ 7FB039F7                                                   │
+└──────────────┘
-│ aes-256-cfb128 │ 5CBD20F7ABD3AC41FCAA1A5C0E119E2BB5174F                     │
+```
-└────────────────┴────────────────────────────────────────────────────────────┘
+
+Which is binary equal to what MySQL produces on same inputs:
+
+``` sql
+mysql> SET  block_encryption_mode='aes-256-cfb128';
+Query OK, 0 rows affected (0.00 sec)
+
+mysql> SELECT aes_encrypt('Secret', '123456789101213141516171819202122', 'iviviviviviviviv123456') as ciphertext;
++------------------------+
+| ciphertext             |
++------------------------+
+| 0x24E9E4966469         |
++------------------------+
+1 row in set (0.00 sec)
 ```
 
 ## decrypt {#decrypt}
 
-This function decrypts data using these modes:
+This function decrypts ciphertext into a plaintext using these modes:
 
 -   aes-128-ecb, aes-192-ecb, aes-256-ecb
 -   aes-128-cbc, aes-192-cbc, aes-256-cbc
@@ -247,7 +234,7 @@ This function decrypts data using these modes:
 
 **Syntax**
 
-```sql
+``` sql
 decrypt('mode', 'ciphertext', 'key' [, iv, aad])
 ```
 
@@ -265,51 +252,56 @@ decrypt('mode', 'ciphertext', 'key' [, iv, aad])
 
 **Examples**
 
-Create this table:
+Re-using table from [encrypt](./encryption-functions.md#encrypt).
 
 Query:
 
 ``` sql
-CREATE TABLE encryption_test
+SELECT comment, hex(secret) FROM encryption_test;
-(
-    input String,
-    key String DEFAULT unhex('fb9958e2e897ef3fdb49067b51a24af645b3626eed2f9ea1dc7fd4dd71b7e38f9a68db2a3184f952382c783785f9d77bf923577108a88adaacae5c141b1576b0'),
-    iv String DEFAULT unhex('8CA3554377DFF8A369BC50A89780DD85'),
-    key32 String DEFAULT substring(key, 1, 32),
-    key24 String DEFAULT substring(key, 1, 24),
-    key16 String DEFAULT substring(key, 1, 16)
-) Engine = Memory;
-```
-
-Insert this data:
-
-Query:
-
-``` sql
-INSERT INTO encryption_test (input) VALUES (''), ('text'), ('What Is ClickHouse?');
-```
-
-Query:
-
-``` sql
-
-SELECT 'aes-128-ecb' AS mode, decrypt(mode, encrypt(mode, input, key16), key16) FROM encryption_test;
 ```
 
 Result:
 
-```text
+``` text
-┌─mode────────┬─decrypt('aes-128-ecb', encrypt('aes-128-ecb', input, key16), key16)─┐
+┌─comment──────────────┬─hex(secret)──────────────────────────────────┐
-│ aes-128-ecb │                                                                     │
+│ aes-256-gcm          │ A8A3CCBC6426CFEEB60E4EAE03D3E94204C1B09E0254 │
-│ aes-128-ecb │ text                                                                │
+│ aes-256-gcm with AAD │ A8A3CCBC6426D9A1017A0A932322F1852260A4AD6837 │
-│ aes-128-ecb │ What Is ClickHouse?                                                 │
+└──────────────────────┴──────────────────────────────────────────────┘
-└─────────────┴─────────────────────────────────────────────────────────────────────┘
+┌─comment─────────────────────────────┬─hex(secret)──────────────────────┐
+│ aes-256-cfb128 no IV                │ B4972BDC4459                     │
+│ aes-256-cfb128 no IV, different key │ 2FF57C092DC9                     │
+│ aes-256-cfb128 with IV              │ 5E6CB398F653                     │
+│ aes-256-cbc no IV                   │ 1BC0629A92450D9E73A00E7D02CF4142 │
+└─────────────────────────────────────┴──────────────────────────────────┘
 ```
 
+Now let's try to decrypt all that data.
+
+Query:
+
+``` sql
+SELECT comment, decrypt('aes-256-cfb128', secret, '12345678910121314151617181920212') as plaintext FROM encryption_test
+```
+
+Result:
+``` text
+┌─comment─────────────────────────────┬─plaintext─┐
+│ aes-256-cfb128 no IV                │ Secret    │
+│ aes-256-cfb128 no IV, different key │ <20>4<EFBFBD>
+                                           <20>         │
+│ aes-256-cfb128 with IV              │ <20><><EFBFBD>6<EFBFBD>~        │
+ │aes-256-cbc no IV                   │ <20>2*4<>h3c<33>4w<34><77>@
+└─────────────────────────────────────┴───────────┘
+```
+
+Notice how only portion of the data was properly decrypted, and the rest is gibberish since either `mode`, `key`, or `iv` were different upon encryption.
+
 ## aes_decrypt_mysql {#aes_decrypt_mysql}
 
 Compatible with mysql encryption and decrypts data encrypted with [AES_ENCRYPT](https://dev.mysql.com/doc/refman/8.0/en/encryption-functions.html#function_aes-encrypt) function.
 
+Will produce same plaintext as `decrypt` on equal inputs. But when `key` or `iv` are longer than they should normally be, `aes_decrypt_mysql` will stick to what MySQL's `aes_decrypt` does: 'fold' `key` and ignore excess bits of `IV`.
+
 Supported decryption modes:
 
 -   aes-128-ecb, aes-192-ecb, aes-256-ecb
@@ -321,7 +313,7 @@ Supported decryption modes:
 
 **Syntax**
 
-```sql
+``` sql
 aes_decrypt_mysql('mode', 'ciphertext', 'key' [, iv])
 ```
 
@@ -338,44 +330,30 @@ aes_decrypt_mysql('mode', 'ciphertext', 'key' [, iv])
 
 **Examples**
 
-Create this table:
+Let's decrypt data we've previously encrypted with MySQL:
-
-Query:
-
 ``` sql
-CREATE TABLE encryption_test
+mysql> SET  block_encryption_mode='aes-256-cfb128';
-(
+Query OK, 0 rows affected (0.00 sec)
-    input String,
-    key String DEFAULT unhex('fb9958e2e897ef3fdb49067b51a24af645b3626eed2f9ea1dc7fd4dd71b7e38f9a68db2a3184f952382c783785f9d77bf923577108a88adaacae5c141b1576b0'),
-    iv String DEFAULT unhex('8CA3554377DFF8A369BC50A89780DD85'),
-    key32 String DEFAULT substring(key, 1, 32),
-    key24 String DEFAULT substring(key, 1, 24),
-    key16 String DEFAULT substring(key, 1, 16)
-) Engine = Memory;
-```
 
-Insert this data:
+mysql> SELECT aes_encrypt('Secret', '123456789101213141516171819202122', 'iviviviviviviviv123456') as ciphertext;
-
++------------------------+
-Query:
+| ciphertext             |
-
++------------------------+
-``` sql
+| 0x24E9E4966469         |
-INSERT INTO encryption_test (input) VALUES (''), ('text'), ('What Is ClickHouse?');
++------------------------+
+1 row in set (0.00 sec)
 ```
 
 Query:
-
 ``` sql
-SELECT 'aes-128-cbc' AS mode, aes_decrypt_mysql(mode, aes_encrypt_mysql(mode, input, key), key) FROM encryption_test;
+SELECT aes_decrypt_mysql('aes-256-cfb128', unhex('24E9E4966469'), '123456789101213141516171819202122', 'iviviviviviviviv123456') AS plaintext
 ```
 
 Result:
-
 ``` text
-┌─mode────────┬─aes_decrypt_mysql('aes-128-cbc', aes_encrypt_mysql('aes-128-cbc', input, key), key)─┐
+┌─plaintext─┐
-│ aes-128-cbc │                                                                                     │
+│ Secret    │
-│ aes-128-cbc │ text                                                                                │
+└───────────┘
-│ aes-128-cbc │ What Is ClickHouse?                                                                 │
-└─────────────┴─────────────────────────────────────────────────────────────────────────────────────┘
 ```
 
 [Original article](https://clickhouse.tech/docs/en/sql-reference/functions/encryption_functions/) <!--hide-->

docs/en/sql-reference/functions/ip-address-functions.md

@@ -116,8 +116,19 @@ LIMIT 10
 ## IPv6StringToNum(s) {#ipv6stringtonums}
 
 The reverse function of IPv6NumToString. If the IPv6 address has an invalid format, it returns a string of null bytes. 
+If the IP address is a valid IPv4 address then the IPv6 equivalent of the IPv4 address is returned.
 HEX can be uppercase or lowercase.
 
+``` sql
+SELECT cutIPv6(IPv6StringToNum('127.0.0.1'), 0, 0);
+```
+
+``` text
+┌─cutIPv6(IPv6StringToNum('127.0.0.1'), 0, 0)─┐
+│ ::ffff:127.0.0.1                            │
+└─────────────────────────────────────────────┘
+```
+
 ## IPv4ToIPv6(x) {#ipv4toipv6x}
 
 Takes a `UInt32` number. Interprets it as an IPv4 address in [big endian](https://en.wikipedia.org/wiki/Endianness). Returns a `FixedString(16)` value containing the IPv6 address in binary format. Examples:
@@ -214,6 +225,7 @@ SELECT
 ## toIPv6(string) {#toipv6string}
 
 An alias to `IPv6StringToNum()` that takes a string form of IPv6 address and returns value of [IPv6](../../sql-reference/data-types/domains/ipv6.md) type, which is binary equal to value returned by `IPv6StringToNum()`.
+If the IP address is a valid IPv4 address then the IPv6 equivalent of the IPv4 address is returned.
 
 ``` sql
 WITH
@@ -243,4 +255,42 @@ SELECT
 └───────────────────────────────────┴──────────────────────────────────┘
 ```
 
+``` sql
+SELECT toIPv6('127.0.0.1')
+```
+
+``` text
+┌─toIPv6('127.0.0.1')─┐
+│ ::ffff:127.0.0.1    │
+└─────────────────────┘
+```
+
+## isIPv4String
+
+Determines if the input string is an IPv4 address or not. Returns `1` if true `0` otherwise.
+
+``` sql
+SELECT isIPv4String('127.0.0.1')
+```
+
+``` text
+┌─isIPv4String('127.0.0.1')─┐
+│                         1 │
+└───────────────────────────┘
+```
+
+## isIPv6String
+
+Determines if the input string is an IPv6 address or not. Returns `1` if true `0` otherwise.
+
+``` sql
+SELECT isIPv6String('2001:438:ffff::407d:1bc1')
+```
+
+``` text
+┌─isIPv6String('2001:438:ffff::407d:1bc1')─┐
+│                                        1 │
+└──────────────────────────────────────────┘
+```
+
 [Original article](https://clickhouse.tech/docs/en/query_language/functions/ip_address_functions/) <!--hide-->

docs/en/sql-reference/functions/math-functions.md

@@ -413,4 +413,68 @@ Result:
 
 -   [log(x)](../../sql-reference/functions/math-functions.md#logx-lnx)
 
+## sign(x) {#signx}
+
+The `sign` function can extract the sign of a real number.
+
+**Syntax**
+
+``` sql
+sign(x)
+```
+
+**Parameters**
+
+-   `x` — Values from  `-∞` to `+∞`. Support all numeric types in ClickHouse.
+
+**Returned value**
+
+- -1 for `x < 0`
+-  0 for `x = 0`
+-  1 for `x > 0`
+
+**Example**
+
+Query:
+
+``` sql
+SELECT sign(0);
+```
+
+Result:
+
+``` text
+┌─sign(0)─┐
+│       0 │
+└─────────┘
+```
+
+Query:
+
+``` sql
+SELECT sign(1);
+```
+
+Result:
+
+``` text
+┌─sign(1)─┐
+│       1 │
+└─────────┘
+```
+
+Query:
+
+``` sql
+SELECT sign(-1);
+```
+
+Result:
+
+``` text
+┌─sign(-1)─┐
+│       -1 │
+└──────────┘
+```
+
 [Original article](https://clickhouse.tech/docs/en/query_language/functions/math_functions/) <!--hide-->

docs/en/sql-reference/functions/other-functions.md

@@ -1468,7 +1468,7 @@ Code: 395. DB::Exception: Received from localhost:9000. DB::Exception: Too many.
 
 ## identity {#identity}
 
-Returns the same value that was used as its argument. Used for debugging and testing, allows to cancel using index, and get the query performance of a full scan. When query is analyzed for possible use of index, the analyzer doesn’t look inside `identity` functions.
+Returns the same value that was used as its argument. Used for debugging and testing, allows to cancel using index, and get the query performance of a full scan. When query is analyzed for possible use of index, the analyzer doesn’t look inside `identity` functions. Also constant folding is not applied too.
 
 **Syntax**
 

docs/en/sql-reference/functions/string-functions.md

@@ -574,7 +574,7 @@ encodeXMLComponent(x)
 
 -   `x` — The sequence of characters. [String](../../sql-reference/data-types/string.md).
 
-**Returned value(s)**
+**Returned value**
 
 -   The sequence of characters with escape characters.
 

docs/en/sql-reference/statements/alter/quota.md

@@ -5,16 +5,35 @@ toc_title: QUOTA
 
 # ALTER QUOTA {#alter-quota-statement}
 
-Changes quotas.
+Changes [quotas](../../../operations/access-rights.md#quotas-management).
 
 Syntax:
 
 ``` sql
 ALTER QUOTA [IF EXISTS] name [ON CLUSTER cluster_name]
     [RENAME TO new_name]
-    [KEYED BY {'none' | 'user name' | 'ip address' | 'client key' | 'client key or user name' | 'client key or ip address'}]
+    [KEYED BY {user_name | ip_address | client_key | client_key,user_name | client_key,ip_address} | NOT KEYED]
-    [FOR [RANDOMIZED] INTERVAL number {SECOND | MINUTE | HOUR | DAY | WEEK | MONTH | QUARTER | YEAR}
+    [FOR [RANDOMIZED] INTERVAL number {second | minute | hour | day | week | month | quarter | year}
-        {MAX { {QUERIES | ERRORS | RESULT ROWS | RESULT BYTES | READ ROWS | READ BYTES | EXECUTION TIME} = number } [,...] |
+        {MAX { {queries | errors | result_rows | result_bytes | read_rows | read_bytes | execution_time} = number } [,...] |
         NO LIMITS | TRACKING ONLY} [,...]]
     [TO {role [,...] | ALL | ALL EXCEPT role [,...]}]
 ```
+Keys `user_name`, `ip_address`, `client_key`, `client_key, user_name` and `client_key, ip_address` correspond to the fields in the [system.quotas](../../../operations/system-tables/quotas.md) table.
+
+Parameters `queries`, `errors`, `result_rows`, `result_bytes`, `read_rows`, `read_bytes`, `execution_time` correspond to the fields in the [system.quotas_usage](../../../operations/system-tables/quotas_usage.md) table.
+
+`ON CLUSTER` clause allows creating quotas on a cluster, see [Distributed DDL](../../../sql-reference/distributed-ddl.md).
+
+**Examples**
+
+Limit the maximum number of queries for the current user with 123 queries in 15 months constraint:
+
+``` sql
+ALTER QUOTA IF EXISTS qA FOR INTERVAL 15 month MAX queries = 123 TO CURRENT_USER;
+```
+
+For the default user limit the maximum execution time with half a second in 30 minutes, and limit the maximum number of queries with 321 and the maximum number of errors with 10 in 5 quaters:
+
+``` sql
+ALTER QUOTA IF EXISTS qB FOR INTERVAL 30 minute MAX execution_time = 0.5, FOR INTERVAL 5 quarter MAX queries = 321, errors = 10 TO default;
+```

docs/en/sql-reference/statements/alter/role.md

@@ -10,7 +10,7 @@ Changes roles.
 Syntax:
 
 ``` sql
-ALTER ROLE [IF EXISTS] name [ON CLUSTER cluster_name]
+ALTER ROLE [IF EXISTS] name1 [ON CLUSTER cluster_name1] [RENAME TO new_name1] 
-    [RENAME TO new_name]
+        [, name2 [ON CLUSTER cluster_name2] [RENAME TO new_name2] ...]
     [SETTINGS variable [= value] [MIN [=] min_value] [MAX [=] max_value] [READONLY|WRITABLE] | PROFILE 'profile_name'] [,...]
 ```

docs/en/sql-reference/statements/alter/row-policy.md

@@ -10,8 +10,8 @@ Changes row policy.
 Syntax:
 
 ``` sql
-ALTER [ROW] POLICY [IF EXISTS] name [ON CLUSTER cluster_name] ON [database.]table
+ALTER [ROW] POLICY [IF EXISTS] name1 [ON CLUSTER cluster_name1] ON [database1.]table1 [RENAME TO new_name1] 
-    [RENAME TO new_name]
+        [, name2 [ON CLUSTER cluster_name2] ON [database2.]table2 [RENAME TO new_name2] ...]
     [AS {PERMISSIVE | RESTRICTIVE}]
     [FOR SELECT]
     [USING {condition | NONE}][,...]

docs/en/sql-reference/statements/alter/settings-profile.md

@@ -10,7 +10,7 @@ Changes settings profiles.
 Syntax:
 
 ``` sql
-ALTER SETTINGS PROFILE [IF EXISTS] TO name [ON CLUSTER cluster_name]
+ALTER SETTINGS PROFILE [IF EXISTS] TO name1 [ON CLUSTER cluster_name1] [RENAME TO new_name1]
-    [RENAME TO new_name]
+        [, name2 [ON CLUSTER cluster_name2] [RENAME TO new_name2] ...]
     [SETTINGS variable [= value] [MIN [=] min_value] [MAX [=] max_value] [READONLY|WRITABLE] | INHERIT 'profile_name'] [,...]
 ```

docs/en/sql-reference/statements/alter/user.md

@@ -10,8 +10,8 @@ Changes ClickHouse user accounts.
 Syntax:
 
 ``` sql
-ALTER USER [IF EXISTS] name [ON CLUSTER cluster_name]
+ALTER USER [IF EXISTS] name1 [ON CLUSTER cluster_name1] [RENAME TO new_name1] 
-    [RENAME TO new_name]
+        [, name2 [ON CLUSTER cluster_name2] [RENAME TO new_name2] ...]
     [IDENTIFIED [WITH {PLAINTEXT_PASSWORD|SHA256_PASSWORD|DOUBLE_SHA1_PASSWORD}] BY {'password'|'hash'}]
     [[ADD|DROP] HOST {LOCAL | NAME 'name' | REGEXP 'name_regexp' | IP 'address' | LIKE 'pattern'} [,...] | ANY | NONE]
     [DEFAULT ROLE role [,...] | ALL | ALL EXCEPT role [,...] ]

docs/en/sql-reference/statements/create/quota.md

@@ -11,19 +11,29 @@ Syntax:
 
 ``` sql
 CREATE QUOTA [IF NOT EXISTS | OR REPLACE] name [ON CLUSTER cluster_name]
-    [KEYED BY {'none' | 'user name' | 'ip address' | 'forwarded ip address' | 'client key' | 'client key or user name' | 'client key or ip address'}]
+    [KEYED BY {user_name | ip_address | client_key | client_key,user_name | client_key,ip_address} | NOT KEYED]
-    [FOR [RANDOMIZED] INTERVAL number {SECOND | MINUTE | HOUR | DAY | WEEK | MONTH | QUARTER | YEAR}
+    [FOR [RANDOMIZED] INTERVAL number {second | minute | hour | day | week | month | quarter | year}
-        {MAX { {QUERIES | ERRORS | RESULT ROWS | RESULT BYTES | READ ROWS | READ BYTES | EXECUTION TIME} = number } [,...] |
+        {MAX { {queries | errors | result_rows | result_bytes | read_rows | read_bytes | execution_time} = number } [,...] |
          NO LIMITS | TRACKING ONLY} [,...]]
     [TO {role [,...] | ALL | ALL EXCEPT role [,...]}]
 ```
 
+Keys `user_name`, `ip_address`, `client_key`, `client_key, user_name` and `client_key, ip_address` correspond to the fields in the [system.quotas](../../../operations/system-tables/quotas.md) table.
+
+Parameters `queries`, `errors`, `result_rows`, `result_bytes`, `read_rows`, `read_bytes`, `execution_time` correspond to the fields in the [system.quotas_usage](../../../operations/system-tables/quotas_usage.md) table.
+
 `ON CLUSTER` clause allows creating quotas on a cluster, see [Distributed DDL](../../../sql-reference/distributed-ddl.md).
 
-## Example {#create-quota-example}
+**Examples** 
 
 Limit the maximum number of queries for the current user with 123 queries in 15 months constraint:
 
 ``` sql
-CREATE QUOTA qA FOR INTERVAL 15 MONTH MAX QUERIES 123 TO CURRENT_USER
+CREATE QUOTA qA FOR INTERVAL 15 month MAX queries = 123 TO CURRENT_USER;
+```
+
+For the default user limit the maximum execution time with half a second in 30 minutes, and limit the maximum number of queries with 321 and the maximum number of errors with 10 in 5 quaters:
+
+``` sql
+CREATE QUOTA qB FOR INTERVAL 30 minute MAX execution_time = 0.5, FOR INTERVAL 5 quarter MAX queries = 321, errors = 10 TO default;
 ```

docs/en/sql-reference/statements/create/role.md

@@ -5,12 +5,12 @@ toc_title: ROLE
 
 # CREATE ROLE {#create-role-statement}
 
-Creates a new [role](../../../operations/access-rights.md#role-management). Role is a set of [privileges](../../../sql-reference/statements/grant.md#grant-privileges). A [user](../../../sql-reference/statements/create/user.md) assigned a role gets all the privileges of this role.
+Creates new [roles](../../../operations/access-rights.md#role-management). Role is a set of [privileges](../../../sql-reference/statements/grant.md#grant-privileges). A [user](../../../sql-reference/statements/create/user.md) assigned a role gets all the privileges of this role.
 
 Syntax:
 
 ``` sql
-CREATE ROLE [IF NOT EXISTS | OR REPLACE] name
+CREATE ROLE [IF NOT EXISTS | OR REPLACE] name1 [, name2 ...]
     [SETTINGS variable [= value] [MIN [=] min_value] [MAX [=] max_value] [READONLY|WRITABLE] | PROFILE 'profile_name'] [,...]
 ```
 

docs/en/sql-reference/statements/create/row-policy.md

@@ -5,16 +5,17 @@ toc_title: ROW POLICY
 
 # CREATE ROW POLICY {#create-row-policy-statement}
 
-Creates a [filter for rows](../../../operations/access-rights.md#row-policy-management), which a user can read from a table.
+Creates [filters for rows](../../../operations/access-rights.md#row-policy-management), which a user can read from a table.
 
 Syntax:
 
 ``` sql
-CREATE [ROW] POLICY [IF NOT EXISTS | OR REPLACE] policy_name [ON CLUSTER cluster_name] ON [db.]table
+CREATE [ROW] POLICY [IF NOT EXISTS | OR REPLACE] policy_name1 [ON CLUSTER cluster_name1] ON [db1.]table1 
+        [, policy_name2 [ON CLUSTER cluster_name2] ON [db2.]table2 ...] 
     [AS {PERMISSIVE | RESTRICTIVE}]
     [FOR SELECT]
     [USING condition]
-    [TO {role [,...] | ALL | ALL EXCEPT role [,...]}]
+    [TO {role1 [, role2 ...] | ALL | ALL EXCEPT role1 [, role2 ...]}]
 ```
 
 `ON CLUSTER` clause allows creating row policies on a cluster, see [Distributed DDL](../../../sql-reference/distributed-ddl.md).

docs/en/sql-reference/statements/create/settings-profile.md

@@ -5,12 +5,13 @@ toc_title: SETTINGS PROFILE
 
 # CREATE SETTINGS PROFILE {#create-settings-profile-statement}
 
-Creates a [settings profile](../../../operations/access-rights.md#settings-profiles-management) that can be assigned to a user or a role.
+Creates [settings profiles](../../../operations/access-rights.md#settings-profiles-management) that can be assigned to a user or a role.
 
 Syntax:
 
 ``` sql
-CREATE SETTINGS PROFILE [IF NOT EXISTS | OR REPLACE] TO name [ON CLUSTER cluster_name]
+CREATE SETTINGS PROFILE [IF NOT EXISTS | OR REPLACE] TO name1 [ON CLUSTER cluster_name1] 
+        [, name2 [ON CLUSTER cluster_name2] ...]
     [SETTINGS variable [= value] [MIN [=] min_value] [MAX [=] max_value] [READONLY|WRITABLE] | INHERIT 'profile_name'] [,...]
 ```
 

docs/en/sql-reference/statements/create/table.md

@@ -23,7 +23,7 @@ CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]
 ```
 
 Creates a table named `name` in the `db` database or the current database if `db` is not set, with the structure specified in brackets and the `engine` engine.
-The structure of the table is a list of column descriptions, secondary indexes and constraints . If primary key is supported by the engine, it will be indicated as parameter for the table engine.
+The structure of the table is a list of column descriptions, secondary indexes and constraints . If [primary key](#primary-key) is supported by the engine, it will be indicated as parameter for the table engine.
 
 A column description is `name type` in the simplest case. Example: `RegionID UInt32`.
 
@@ -39,13 +39,13 @@ CREATE TABLE [IF NOT EXISTS] [db.]table_name AS [db2.]name2 [ENGINE = engine]
 
 Creates a table with the same structure as another table. You can specify a different engine for the table. If the engine is not specified, the same engine will be used as for the `db2.name2` table.
 
-## From a Table Function {#from-a-table-function}
+### From a Table Function {#from-a-table-function}
 
 ``` sql
 CREATE TABLE [IF NOT EXISTS] [db.]table_name AS table_function()
 ```
 
-Creates a table with the structure and data returned by a [table function](../../../sql-reference/table-functions/index.md#table-functions).
+Creates a table with the same result as that of the [table function](../../../sql-reference/table-functions/index.md#table-functions) specified. The created table will also work in the same way as the corresponding table function that was specified.
 
 ``` sql
 CREATE TABLE [IF NOT EXISTS] [db.]table_name ENGINE = engine AS SELECT ...
@@ -111,7 +111,7 @@ It is not possible to set default values for elements in nested data structures.
 
 You can define a [primary key](../../../engines/table-engines/mergetree-family/mergetree.md#primary-keys-and-indexes-in-queries) when creating a table. Primary key can be specified in two ways: 
 
-- inside the column list
+- Inside the column list
 
 ``` sql
 CREATE TABLE db.table_name 
@@ -122,7 +122,7 @@ CREATE TABLE db.table_name
 ENGINE = engine;
 ```
 
-- outside the column list
+- Outside the column list
 
 ``` sql
 CREATE TABLE db.table_name
@@ -133,7 +133,8 @@ ENGINE = engine
 PRIMARY KEY(expr1[, expr2,...]);
 ```
 
-You can't combine both ways in one query.
+!!! warning "Warning"
+    You can't combine both ways in one query.
 
 ## Constraints {#constraints}
 
@@ -259,3 +260,78 @@ CREATE TEMPORARY TABLE [IF NOT EXISTS] table_name
 In most cases, temporary tables are not created manually, but when using external data for a query, or for distributed `(GLOBAL) IN`. For more information, see the appropriate sections
 
 It’s possible to use tables with [ENGINE = Memory](../../../engines/table-engines/special/memory.md) instead of temporary tables.
+
+## REPLACE TABLE {#replace-table-query}
+
+'REPLACE' query allows you to update the table atomically.
+
+!!!note "Note"
+    This query is supported only for [Atomic](../../../engines/database-engines/atomic.md) database engine.
+
+If you need to delete some data from a table, you can create a new table and fill it with a `SELECT` statement that doesn't retrieve unwanted data, then drop the old table and rename the new one:
+
+```sql
+CREATE TABLE myNewTable AS myOldTable;
+INSERT INTO myNewTable SELECT * FROM myOldTable WHERE CounterID <12345;
+DROP TABLE myOldTable;
+RENAME TABLE myNewTable TO myOldTable;
+```
+
+Instead of above, you can use the following:
+
+```sql
+REPLACE TABLE myOldTable SELECT * FROM myOldTable WHERE CounterID <12345;
+```
+
+### Syntax
+
+{CREATE [OR REPLACE]|REPLACE} TABLE [db.]table_name
+
+All syntax forms for `CREATE` query also work for this query. `REPLACE` for a non-existent table will cause an error.
+
+### Examples:
+
+Consider the table:
+
+```sql
+CREATE DATABASE base ENGINE = Atomic;
+CREATE OR REPLACE TABLE base.t1 (n UInt64, s String) ENGINE = MergeTree ORDER BY n;
+INSERT INTO base.t1 VALUES (1, 'test');
+SELECT * FROM base.t1;
+```
+
+```text
+┌─n─┬─s────┐
+│ 1 │ test │
+└───┴──────┘
+```
+
+Using `REPLACE` query to clear all data:
+
+```sql
+CREATE OR REPLACE TABLE base.t1 (n UInt64, s Nullable(String)) ENGINE = MergeTree ORDER BY n;
+INSERT INTO base.t1 VALUES (2, null);
+SELECT * FROM base.t1;
+```
+
+```text
+┌─n─┬─s──┐
+│ 2 │ \N │
+└───┴────┘
+```
+
+Using `REPLACE` query to change table structure:
+
+```sql
+REPLACE TABLE base.t1 (n UInt64) ENGINE = MergeTree ORDER BY n;
+INSERT INTO base.t1 VALUES (3);
+SELECT * FROM base.t1;
+```
+
+```text
+┌─n─┐
+│ 3 │
+└───┘
+```
+
+ [Original article](https://clickhouse.tech/docs/en/sql-reference/statements/create/table) <!--hide-->

docs/en/sql-reference/statements/create/user.md

@@ -5,12 +5,13 @@ toc_title: USER
 
 # CREATE USER {#create-user-statement}
 
-Creates a [user account](../../../operations/access-rights.md#user-account-management).
+Creates [user accounts](../../../operations/access-rights.md#user-account-management).
 
 Syntax:
 
 ``` sql
-CREATE USER [IF NOT EXISTS | OR REPLACE] name [ON CLUSTER cluster_name]
+CREATE USER [IF NOT EXISTS | OR REPLACE] name1 [ON CLUSTER cluster_name1] 
+        [, name2 [ON CLUSTER cluster_name2] ...]
     [IDENTIFIED [WITH {NO_PASSWORD|PLAINTEXT_PASSWORD|SHA256_PASSWORD|SHA256_HASH|DOUBLE_SHA1_PASSWORD|DOUBLE_SHA1_HASH}] BY {'password'|'hash'}]
     [HOST {LOCAL | NAME 'name' | REGEXP 'name_regexp' | IP 'address' | LIKE 'pattern'} [,...] | ANY | NONE]
     [DEFAULT ROLE role [,...]]
@@ -69,7 +70,7 @@ CREATE USER john DEFAULT ROLE role1, role2
 Create the user account `john` and make all his future roles default:
 
 ``` sql
-ALTER USER user DEFAULT ROLE ALL
+CREATE USER user DEFAULT ROLE ALL
 ```
 
 When some role is assigned to `john` in the future, it will become default automatically.
@@ -77,5 +78,5 @@ When some role is assigned to `john` in the future, it will become default autom
 Create the user account `john` and make all his future roles default excepting `role1` and `role2`:
 
 ``` sql
-ALTER USER john DEFAULT ROLE ALL EXCEPT role1, role2
+CREATE USER john DEFAULT ROLE ALL EXCEPT role1, role2
 ```

docs/en/sql-reference/statements/insert-into.md

@@ -13,7 +13,7 @@ Basic query format:
 INSERT INTO [db.]table [(c1, c2, c3)] VALUES (v11, v12, v13), (v21, v22, v23), ...
 ```
 
-You can specify a list of columns to insert using  the `(c1, c2, c3)`. You can also use an expression with column [matcher](../../sql-reference/statements/select/index.md#asterisk) such as `*` and/or [modifiers](../../sql-reference/statements/select/index.md#select-modifiers) such as [APPLY](../../sql-reference/statements/select/index.md#apply-modifier), [EXCEPT](../../sql-reference/statements/select/index.md#apply-modifier), [REPLACE](../../sql-reference/statements/select/index.md#replace-modifier). 
+You can specify a list of columns to insert using  the `(c1, c2, c3)`. You can also use an expression with column [matcher](../../sql-reference/statements/select/index.md#asterisk) such as `*` and/or [modifiers](../../sql-reference/statements/select/index.md#select-modifiers) such as [APPLY](../../sql-reference/statements/select/index.md#apply-modifier), [EXCEPT](../../sql-reference/statements/select/index.md#except-modifier), [REPLACE](../../sql-reference/statements/select/index.md#replace-modifier).
 
 For example, consider the table:
 
@@ -30,7 +30,6 @@ CREATE TABLE insert_select_testtable
 )
 ENGINE = MergeTree()
 ORDER BY a
-SETTINGS index_granularity = 8192 
 ```
 
 ``` sql

docs/en/sql-reference/statements/select/from.md

@@ -25,6 +25,8 @@ It is applicable when selecting data from tables that use the [MergeTree](../../
 -   [Replicated](../../../engines/table-engines/mergetree-family/replication.md) versions of `MergeTree` engines.
 -   [View](../../../engines/table-engines/special/view.md), [Buffer](../../../engines/table-engines/special/buffer.md), [Distributed](../../../engines/table-engines/special/distributed.md), and [MaterializedView](../../../engines/table-engines/special/materializedview.md) engines that operate over other engines, provided they were created over `MergeTree`-engine tables.
 
+Now `SELECT` queries with `FINAL` are executed in parallel and slightly faster. But there are drawbacks (see below). The [max_final_threads](../../../operations/settings/settings.md#max-final-threads) setting limits the number of threads used.
+
 ### Drawbacks {#drawbacks}
 
 Queries that use `FINAL` are executed slightly slower than similar queries that don’t, because:

docs/en/sql-reference/statements/select/index.md

@@ -278,5 +278,4 @@ Other ways to make settings see [here](../../../operations/settings/index.md).
 SELECT * FROM some_table SETTINGS optimize_read_in_order=1, cast_keep_nullable=1;
 ```
 
-[Original article](https://clickhouse.tech/docs/en/sql-reference/statements/select/)
+[Original article](https://clickhouse.tech/docs/en/sql-reference/statements/select/)<!--hide-->
-<!--hide-->

docs/en/sql-reference/statements/show.md

@@ -231,7 +231,7 @@ Shows privileges for a user.
 ### Syntax {#show-grants-syntax}
 
 ``` sql
-SHOW GRANTS [FOR user]
+SHOW GRANTS [FOR user1 [, user2 ...]]
 ```
 
 If user is not specified, the query returns privileges for the current user.
@@ -245,7 +245,7 @@ Shows parameters that were used at a [user creation](../../sql-reference/stateme
 ### Syntax {#show-create-user-syntax}
 
 ``` sql
-SHOW CREATE USER [name | CURRENT_USER]
+SHOW CREATE USER [name1 [, name2 ...] | CURRENT_USER]
 ```
 
 ## SHOW CREATE ROLE {#show-create-role-statement}
@@ -255,7 +255,7 @@ Shows parameters that were used at a [role creation](../../sql-reference/stateme
 ### Syntax {#show-create-role-syntax}
 
 ``` sql
-SHOW CREATE ROLE name
+SHOW CREATE ROLE name1 [, name2 ...]
 ```
 
 ## SHOW CREATE ROW POLICY {#show-create-row-policy-statement}
@@ -265,7 +265,7 @@ Shows parameters that were used at a [row policy creation](../../sql-reference/s
 ### Syntax {#show-create-row-policy-syntax}
 
 ``` sql
-SHOW CREATE [ROW] POLICY name ON [database.]table
+SHOW CREATE [ROW] POLICY name ON [database1.]table1 [, [database2.]table2 ...]
 ```
 
 ## SHOW CREATE QUOTA {#show-create-quota-statement}
@@ -275,7 +275,7 @@ Shows parameters that were used at a [quota creation](../../sql-reference/statem
 ### Syntax {#show-create-quota-syntax}
 
 ``` sql
-SHOW CREATE QUOTA [name | CURRENT]
+SHOW CREATE QUOTA [name1 [, name2 ...] | CURRENT]
 ```
 
 ## SHOW CREATE SETTINGS PROFILE {#show-create-settings-profile-statement}
@@ -285,7 +285,7 @@ Shows parameters that were used at a [settings profile creation](../../sql-refer
 ### Syntax {#show-create-settings-profile-syntax}
 
 ``` sql
-SHOW CREATE [SETTINGS] PROFILE name
+SHOW CREATE [SETTINGS] PROFILE name1 [, name2 ...]
 ```
 
 ## SHOW USERS {#show-users-statement}
@@ -307,7 +307,6 @@ Returns a list of [roles](../../operations/access-rights.md#role-management). To
 ``` sql
 SHOW [CURRENT|ENABLED] ROLES
 ```
-
 ## SHOW PROFILES {#show-profiles-statement}
 
 Returns a list of [setting profiles](../../operations/access-rights.md#settings-profiles-management). To view user accounts parameters, see the system table [settings_profiles](../../operations/system-tables/settings_profiles.md#system_tables-settings_profiles).
@@ -347,7 +346,15 @@ Returns a [quota](../../operations/quotas.md) consumption for all users or for c
 ``` sql
 SHOW [CURRENT] QUOTA
 ```
+## SHOW ACCESS {#show-access-statement}
 
+Shows all [users](../../operations/access-rights.md#user-account-management), [roles](../../operations/access-rights.md#role-management), [profiles](../../operations/access-rights.md#settings-profiles-management), etc. and all their [grants](../../sql-reference/statements/grant.md#grant-privileges).
+
+### Syntax {#show-access-syntax}
+
+``` sql
+SHOW ACCESS
+```
 ## SHOW CLUSTER(s) {#show-cluster-statement}
 
 Returns a list of clusters. All available clusters are listed in the [system.clusters](../../operations/system-tables/clusters.md) table.

docs/en/sql-reference/table-functions/file.md

@@ -7,21 +7,25 @@ toc_title: file
 
 Creates a table from a file. This table function is similar to [url](../../sql-reference/table-functions/url.md) and [hdfs](../../sql-reference/table-functions/hdfs.md) ones. 
 
+`file` function can be used in `SELECT` and `INSERT` queries on data in [File](../../engines/table-engines/special/file.md) tables.
+
+**Syntax**
+
 ``` sql
 file(path, format, structure)
 ```
 
 **Input parameters**
 
--   `path` — The relative path to the file from [user_files_path](../../operations/server-configuration-parameters/settings.md#server_configuration_parameters-user_files_path). Path to file support following globs in readonly mode: `*`, `?`, `{abc,def}` and `{N..M}` where `N`, `M` — numbers, \``'abc', 'def'` — strings.
+-   `path` — The relative path to the file from [user_files_path](../../operations/server-configuration-parameters/settings.md#server_configuration_parameters-user_files_path). Path to file support following globs in readonly mode: `*`, `?`, `{abc,def}` and `{N..M}` where `N`, `M` — numbers, `'abc', 'def'` — strings.
 -   `format` — The [format](../../interfaces/formats.md#formats) of the file.
--   `structure` — Structure of the table. Format `'column1_name column1_type, column2_name column2_type, ...'`.
+-   `structure` — Structure of the table. Format: `'column1_name column1_type, column2_name column2_type, ...'`.
 
 **Returned value**
 
 A table with the specified structure for reading or writing data in the specified file.
 
-**Example**
+**Examples**
 
 Setting `user_files_path` and the contents of the file `test.csv`:
 
@@ -35,12 +39,29 @@ $ cat /var/lib/clickhouse/user_files/test.csv
     78,43,45
 ```
 
-Table from`test.csv` and selection of the first two rows from it:
+Getting data from a table in `test.csv` and selecting first two rows from it:
 
 ``` sql
-SELECT *
+SELECT * FROM file('test.csv', 'CSV', 'column1 UInt32, column2 UInt32, column3 UInt32') LIMIT 2;
-FROM file('test.csv', 'CSV', 'column1 UInt32, column2 UInt32, column3 UInt32')
+```
-LIMIT 2
+
+``` text
+┌─column1─┬─column2─┬─column3─┐
+│       1 │       2 │       3 │
+│       3 │       2 │       1 │
+└─────────┴─────────┴─────────┘
+```
+Getting the first 10 lines of a table that contains 3 columns of UInt32 type from a CSV file:
+
+``` sql
+SELECT * FROM file('test.csv', 'CSV', 'column1 UInt32, column2 UInt32, column3 UInt32') LIMIT 10;
+```
+
+Inserting data from a file into a table:
+
+``` sql
+INSERT INTO FUNCTION file('test.csv', 'CSV', 'column1 UInt32, column2 UInt32, column3 UInt32') VALUES (1, 2, 3), (3, 2, 1);
+SELECT * FROM file('test.csv', 'CSV', 'column1 UInt32, column2 UInt32, column3 UInt32');
 ```
 
 ``` text
@@ -50,12 +71,8 @@ LIMIT 2
 └─────────┴─────────┴─────────┘
 ```
 
-``` sql
--- getting the first 10 lines of a table that contains 3 columns of UInt32 type from a CSV file
-SELECT * FROM file('test.csv', 'CSV', 'column1 UInt32, column2 UInt32, column3 UInt32') LIMIT 10
-```
 
-**Globs in path**
+## Globs in Path {#globs-in-path}
 
 Multiple path components can have globs. For being processed file should exists and matches to the whole path pattern (not only suffix or prefix).
 
@@ -68,31 +85,25 @@ Constructions with `{}` are similar to the [remote table function](../../sql-ref
 
 **Example**
 
-1.  Suppose we have several files with the following relative paths:
+Suppose we have several files with the following relative paths:
 
--   ‘some_dir/some_file_1’
+-   'some_dir/some_file_1'
--   ‘some_dir/some_file_2’
+-   'some_dir/some_file_2'
--   ‘some_dir/some_file_3’
+-   'some_dir/some_file_3'
--   ‘another_dir/some_file_1’
+-   'another_dir/some_file_1'
--   ‘another_dir/some_file_2’
+-   'another_dir/some_file_2'
--   ‘another_dir/some_file_3’
+-   'another_dir/some_file_3'
 
-1.  Query the amount of rows in these files:
+Query the amount of rows in these files:
-
-<!-- -->
 
 ``` sql
-SELECT count(*)
+SELECT count(*) FROM file('{some,another}_dir/some_file_{1..3}', 'TSV', 'name String, value UInt32');
-FROM file('{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:
+Query the amount of rows in all files of these two directories:
-
-<!-- -->
 
 ``` sql
-SELECT count(*)
+SELECT count(*) FROM file('{some,another}_dir/*', 'TSV', 'name String, value UInt32');
-FROM file('{some,another}_dir/*', 'TSV', 'name String, value UInt32')
 ```
 
 !!! warning "Warning"
@@ -103,8 +114,7 @@ FROM file('{some,another}_dir/*', 'TSV', 'name String, value UInt32')
 Query the data from files named `file000`, `file001`, … , `file999`:
 
 ``` sql
-SELECT count(*)
+SELECT count(*) FROM file('big_dir/file{0..9}{0..9}{0..9}', 'CSV', 'name String, value UInt32');
-FROM file('big_dir/file{0..9}{0..9}{0..9}', 'CSV', 'name String, value UInt32')
 ```
 
 ## Virtual Columns {#virtual-columns}
@@ -116,4 +126,4 @@ FROM file('big_dir/file{0..9}{0..9}{0..9}', 'CSV', 'name String, value UInt32')
 
 -   [Virtual columns](https://clickhouse.tech/docs/en/operations/table_engines/#table_engines-virtual_columns)
 
-[Original article](https://clickhouse.tech/docs/en/query_language/table_functions/file/) <!--hide-->
+[Original article](https://clickhouse.tech/docs/en/sql-reference/table-functions/file/) <!--hide-->

docs/en/sql-reference/table-functions/remote.md

@@ -5,9 +5,11 @@ toc_title: remote
 
 # remote, remoteSecure {#remote-remotesecure}
 
-Allows you to access remote servers without creating a `Distributed` table.
+Allows to access remote servers without creating a [Distributed](../../engines/table-engines/special/distributed.md) table. `remoteSecure` - same as `remote` but with secured connection. 
 
-Signatures:
+Both functions can be used in `SELECT` and `INSERT` queries.
+
+**Syntax**
 
 ``` sql
 remote('addresses_expr', db, table[, 'user'[, 'password'], sharding_key])
@@ -16,13 +18,40 @@ remoteSecure('addresses_expr', db, table[, 'user'[, 'password'], sharding_key])
 remoteSecure('addresses_expr', db.table[, 'user'[, 'password'], sharding_key])
 ```
 
-`addresses_expr` – An expression that generates addresses of remote servers. This may be just one server address. The server address is `host:port`, or just `host`. The host can be specified as the server name, or as the IPv4 or IPv6 address. An IPv6 address is specified in square brackets. The port is the TCP port on the remote server. If the port is omitted, it uses `tcp_port` from the server’s config file (by default, 9000).
+**Input parameters**
-`sharding_key` - We can specify sharding key to support distributing data across nodes. For example: `insert into remote('127.0.0.1:9000,127.0.0.2', db, table, 'default', rand())`.
+
+- `addresses_expr` – An expression that generates addresses of remote servers. This may be just one server address. The server address is `host:port`, or just `host`. 
+   
+    The host can be specified as the server name, or as the IPv4 or IPv6 address. An IPv6 address is specified in square brackets. 
+   
+    The port is the TCP port on the remote server. If the port is omitted, it uses  [tcp_port](../../operations/server-configuration-parameters/settings.md#server_configuration_parameters-tcp_port) from the server’s config file in `remote` (by default, 9000) and [tcp_port_secure](../../operations/server-configuration-parameters/settings.md#server_configuration_parameters-tcp_port_secure) in `remoteSecure` (by default, 9440). 
 
-!!! important "Important"
     The port is required for an IPv6 address.
 
-Examples:
+    Type: [String](../../sql-reference/data-types/string.md).
+
+- `db` - Database name. Type: [String](../../sql-reference/data-types/string.md).
+- `table` - Table name. Type: [String](../../sql-reference/data-types/string.md).
+- `user` - User name. If the user is not specified, `default` is used. Type: [String](../../sql-reference/data-types/string.md).
+- `password` - User password. If the password is not specified, an empty password is used. Type: [String](../../sql-reference/data-types/string.md).
+- `sharding_key` - Sharding key to support distributing data across nodes. For example: `insert into remote('127.0.0.1:9000,127.0.0.2', db, table, 'default', rand())`. Type: [UInt32](../../sql-reference/data-types/int-uint.md).
+
+**Returned value**
+
+Dataset from remote servers.
+
+**Usage**
+
+Using the `remote` table function is less optimal than creating a `Distributed` table, because in this case the server connection is re-established for every request. In addition, if host names are set, the names are resolved, and errors are not counted when working with various replicas. When processing a large number of queries, always create the `Distributed` table ahead of time, and don’t use the `remote` table function.
+
+The `remote` table function can be useful in the following cases:
+
+-   Accessing a specific server for data comparison, debugging, and testing.
+-   Queries between various ClickHouse clusters for research purposes.
+-   Infrequent distributed requests that are made manually.
+-   Distributed requests where the set of servers is re-defined each time.
+
+**Adresses**
 
 ``` text
 example01-01-1
@@ -33,9 +62,7 @@ localhost
 [2a02:6b8:0:1111::11]:9000
 ```
 
-Multiple addresses can be comma-separated. In this case, ClickHouse will use distributed processing, so it will send the query to all specified addresses (like to shards with different data).
+Multiple addresses can be comma-separated. In this case, ClickHouse will use distributed processing, so it will send the query to all specified addresses (like to shards with different data). Example:
-
-Example:
 
 ``` text
 example01-01-1,example01-02-1
@@ -55,30 +82,28 @@ example01-{01..02}-1
 
 If you have multiple pairs of curly brackets, it generates the direct product of the corresponding sets.
 
-Addresses and parts of addresses in curly brackets can be separated by the pipe symbol (\|). In this case, the corresponding sets of addresses are interpreted as replicas, and the query will be sent to the first healthy replica. However, the replicas are iterated in the order currently set in the [load_balancing](../../operations/settings/settings.md) setting.
+Addresses and parts of addresses in curly brackets can be separated by the pipe symbol (\|). In this case, the corresponding sets of addresses are interpreted as replicas, and the query will be sent to the first healthy replica. However, the replicas are iterated in the order currently set in the [load_balancing](../../operations/settings/settings.md) setting. This example specifies two shards that each have two replicas:
-
-Example:
 
 ``` text
 example01-{01..02}-{1|2}
 ```
 
-This example specifies two shards that each have two replicas.
-
 The number of addresses generated is limited by a constant. Right now this is 1000 addresses.
 
-Using the `remote` table function is less optimal than creating a `Distributed` table, because in this case, the server connection is re-established for every request. In addition, if host names are set, the names are resolved, and errors are not counted when working with various replicas. When processing a large number of queries, always create the `Distributed` table ahead of time, and don’t use the `remote` table function.
+**Examples**
 
-The `remote` table function can be useful in the following cases:
+Selecting data from a remote server:
 
--   Accessing a specific server for data comparison, debugging, and testing.
+``` sql
--   Queries between various ClickHouse clusters for research purposes.
+SELECT * FROM remote('127.0.0.1', db.remote_engine_table) LIMIT 3;
--   Infrequent distributed requests that are made manually.
+```
--   Distributed requests where the set of servers is re-defined each time.
 
-If the user is not specified, `default` is used.
+Inserting data from a remote server into a table:
-If the password is not specified, an empty password is used.
 
-`remoteSecure` - same as `remote` but with secured connection. Default port — [tcp_port_secure](../../operations/server-configuration-parameters/settings.md#server_configuration_parameters-tcp_port_secure) from config or 9440.
+``` sql
+CREATE TABLE remote_table (name String, value UInt32) ENGINE=Memory;
+INSERT INTO FUNCTION remote('127.0.0.1', currentDatabase(), 'remote_table') VALUES ('test', 42);
+SELECT * FROM remote_table;
+```
 
-[Original article](https://clickhouse.tech/docs/en/query_language/table_functions/remote/) <!--hide-->
+[Original article](https://clickhouse.tech/docs/en/sql-reference/table-functions/remote/) <!--hide-->

docs/en/sql-reference/table-functions/url.md

@@ -5,20 +5,40 @@ toc_title: url
 
 # url {#url}
 
-`url(URL, format, structure)` - returns a table created from the `URL` with given
+`url` function creates a table from the `URL` with given `format` and `structure`.
-`format` and `structure`.
 
-URL - HTTP or HTTPS server address, which can accept `GET` and/or `POST` requests.
+`url` function may be used in `SELECT` and `INSERT` queries on data in [URL](../../engines/table-engines/special/url.md) tables.
 
-format - [format](../../interfaces/formats.md#formats) of the data.
+**Syntax**
-
-structure - table structure in `'UserID UInt64, Name String'` format. Determines column names and types.
-
-**Example**
 
 ``` sql
--- getting the first 3 lines of a table that contains columns of String and UInt32 type from HTTP-server which answers in CSV format.
+url(URL, format, structure)
-SELECT * FROM url('http://127.0.0.1:12345/', CSV, 'column1 String, column2 UInt32') LIMIT 3
 ```
 
-[Original article](https://clickhouse.tech/docs/en/query_language/table_functions/url/) <!--hide-->
+**Input parameters**
+
+- `URL` - HTTP or HTTPS server address, which can accept `GET` (for `SELECT`) or `POST` (for `INSERT`) requests. Type: [String](../../sql-reference/data-types/string.md).
+- `format` - [Format](../../interfaces/formats.md#formats) of the data. Type: [String](../../sql-reference/data-types/string.md).
+- `structure` - Table structure in `'UserID UInt64, Name String'` format. Determines column names and types. Type: [String](../../sql-reference/data-types/string.md).
+
+**Returned value**
+
+A table with the specified format and structure and with data from the defined URL.
+
+**Examples**
+
+Getting the first 3 lines of a table that contains columns of `String` and `UInt32` type from HTTP-server which answers in `CSV` format.
+
+``` sql
+SELECT * FROM url('http://127.0.0.1:12345/', CSV, 'column1 String, column2 UInt32') LIMIT 3;
+```
+
+Inserting data from a URL into a table:
+
+``` sql
+CREATE TABLE test_table (column1 String, column2 UInt32) ENGINE=Memory;
+INSERT INTO FUNCTION url('http://127.0.0.1:8123/?query=INSERT+INTO+test_table+FORMAT+CSV', 'CSV', 'column1 String, column2 UInt32') VALUES ('http interface', 42);
+SELECT * FROM test_table;
+```
+
+[Original article](https://clickhouse.tech/docs/en/sql-reference/table-functions/url/) <!--hide-->

docs/en/whats-new/roadmap.md

@@ -5,6 +5,6 @@ toc_title: Roadmap
 
 # Roadmap {#roadmap}
 
-The roadmap for year 2021 is published for open discussion [here](https://github.com/ClickHouse/ClickHouse/issues/17623).
+The roadmap for the year 2021 is published for open discussion [here](https://github.com/ClickHouse/ClickHouse/issues/17623).
 
 {## [Original article](https://clickhouse.tech/docs/en/roadmap/) ##}

docs/es/engines/database-engines/atomic.md

@@ -0,0 +1,17 @@
+---
+toc_priority: 32
+toc_title: Atomic
+---
+
+
+# Atomic {#atomic}
+
+It is supports non-blocking `DROP` and `RENAME TABLE` queries and atomic `EXCHANGE TABLES t1 AND t2` queries. Atomic database engine is used by default.
+
+## Creating a Database {#creating-a-database}
+
+```sql
+CREATE DATABASE test ENGINE = Atomic;
+```
+
+[Original article](https://clickhouse.tech/docs/en/engines/database_engines/atomic/) <!--hide-->

docs/es/getting-started/tutorial.md

@@ -256,7 +256,6 @@ ENGINE = MergeTree()
 PARTITION BY toYYYYMM(EventDate)
 ORDER BY (CounterID, EventDate, intHash32(UserID))
 SAMPLE BY intHash32(UserID)
-SETTINGS index_granularity = 8192
 ```
 
 ``` sql
@@ -452,7 +451,6 @@ ENGINE = CollapsingMergeTree(Sign)
 PARTITION BY toYYYYMM(StartDate)
 ORDER BY (CounterID, StartDate, intHash32(UserID), VisitID)
 SAMPLE BY intHash32(UserID)
-SETTINGS index_granularity = 8192
 ```
 
 Puede ejecutar esas consultas utilizando el modo interactivo de `clickhouse-client` (simplemente ejecútelo en un terminal sin especificar una consulta por adelantado) o pruebe algunos [interfaz alternativa](../interfaces/index.md) Si quieres.

docs/fr/engines/database-engines/atomic.md

@@ -0,0 +1,17 @@
+---
+toc_priority: 32
+toc_title: Atomic
+---
+
+
+# Atomic {#atomic}
+
+It is supports non-blocking `DROP` and `RENAME TABLE` queries and atomic `EXCHANGE TABLES t1 AND t2` queries. Atomic database engine is used by default.
+
+## Creating a Database {#creating-a-database}
+
+```sql
+CREATE DATABASE test ENGINE = Atomic;
+```
+
+[Original article](https://clickhouse.tech/docs/en/engines/database_engines/atomic/) <!--hide-->

docs/fr/getting-started/tutorial.md

@@ -256,7 +256,6 @@ ENGINE = MergeTree()
 PARTITION BY toYYYYMM(EventDate)
 ORDER BY (CounterID, EventDate, intHash32(UserID))
 SAMPLE BY intHash32(UserID)
-SETTINGS index_granularity = 8192
 ```
 
 ``` sql
@@ -452,7 +451,6 @@ ENGINE = CollapsingMergeTree(Sign)
 PARTITION BY toYYYYMM(StartDate)
 ORDER BY (CounterID, StartDate, intHash32(UserID), VisitID)
 SAMPLE BY intHash32(UserID)
-SETTINGS index_granularity = 8192
 ```
 
 Vous pouvez exécuter ces requêtes en utilisant le mode interactif de `clickhouse-client` (lancez - le simplement dans un terminal sans spécifier une requête à l'avance) ou essayez-en [interface de rechange](../interfaces/index.md) Si tu veux.

docs/ja/engines/database-engines/atomic.md

@@ -0,0 +1,17 @@
+---
+toc_priority: 32
+toc_title: Atomic
+---
+
+
+# Atomic {#atomic}
+
+It is supports non-blocking `DROP` and `RENAME TABLE` queries and atomic `EXCHANGE TABLES t1 AND t2` queries. Atomic database engine is used by default.
+
+## Creating a Database {#creating-a-database}
+
+```sql
+CREATE DATABASE test ENGINE = Atomic;
+```
+
+[Original article](https://clickhouse.tech/docs/en/engines/database_engines/atomic/) <!--hide-->

docs/ja/getting-started/tutorial.md

@@ -262,7 +262,6 @@ ENGINE = MergeTree()
 PARTITION BY toYYYYMM(EventDate)
 ORDER BY (CounterID, EventDate, intHash32(UserID))
 SAMPLE BY intHash32(UserID)
-SETTINGS index_granularity = 8192
 ```
 
 ``` sql
@@ -458,7 +457,6 @@ ENGINE = CollapsingMergeTree(Sign)
 PARTITION BY toYYYYMM(StartDate)
 ORDER BY (CounterID, StartDate, intHash32(UserID), VisitID)
 SAMPLE BY intHash32(UserID)
-SETTINGS index_granularity = 8192
 ```
 
 これらのクエリは、`clickhouse-client` の対話型モード(事前にクエリを指定せずにターミナルで起動するだけです)を使って実行するか、[代替インターフェイス](../interfaces/index.md) で実行できます。

docs/ru/development/developer-instruction.md

@@ -210,7 +210,7 @@ Mac OS X:
 
 Для запуска сервера из под текущего пользователя, с выводом логов в терминал и с использованием примеров конфигурационных файлов, расположенных в исходниках, перейдите в директорию `ClickHouse/programs/server/` (эта директория находится не в директории build) и выполните:
 
-    ../../../build/programs/clickhouse server
+    ../../build/programs/clickhouse server
 
 В этом случае, ClickHouse будет использовать конфигурационные файлы, расположенные в текущей директории. Вы можете запустить `clickhouse server` из любой директории, передав ему путь к конфигурационному файлу в аргументе командной строки `--config-file`.
 

docs/ru/engines/database-engines/index.md

@@ -4,7 +4,6 @@ toc_priority: 27
 toc_title: "\u0412\u0432\u0435\u0434\u0435\u043d\u0438\u0435"
 ---
 
-
 # Движки баз данных {#dvizhki-baz-dannykh}
 
 Движки баз данных обеспечивают работу с таблицами.
@@ -13,4 +12,10 @@ toc_title: "\u0412\u0432\u0435\u0434\u0435\u043d\u0438\u0435"
 
 Также можно использовать следующие движки баз данных:
 
--   [MySQL](mysql.md)
+-   [MySQL](../../engines/database-engines/mysql.md)
+
+-   [MaterializeMySQL](../../engines/database-engines/materialize-mysql.md)
+
+-   [Lazy](../../engines/database-engines/lazy.md)
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/database_engines/) <!--hide-->

docs/ru/engines/database-engines/materialize-mysql.md

@@ -0,0 +1,159 @@
+---
+toc_priority: 29
+toc_title: MaterializeMySQL
+---
+
+# MaterializeMySQL {#materialize-mysql}
+
+Создает базу данных ClickHouse со всеми таблицами, существующими в MySQL, и всеми данными в этих таблицах.
+
+Сервер ClickHouse работает как реплика MySQL. Он читает файл binlog и выполняет DDL and DML-запросы.
+
+`MaterializeMySQL` — экспериментальный движок баз данных.
+
+## Создание базы данных {#creating-a-database}
+
+``` sql
+CREATE DATABASE [IF NOT EXISTS] db_name [ON CLUSTER cluster]
+ENGINE = MaterializeMySQL('host:port', ['database' | database], 'user', 'password') [SETTINGS ...]
+```
+
+**Параметры движка**
+
+-   `host:port` — адрес сервера MySQL.
+-   `database` — имя базы данных на удалённом сервере.
+-   `user` — пользователь MySQL.
+-   `password` — пароль пользователя.
+
+## Виртуальные столбцы {#virtual-columns}
+
+При работе с движком баз данных `MaterializeMySQL` используются таблицы семейства [ReplacingMergeTree](../../engines/table-engines/mergetree-family/replacingmergetree.md) с виртуальными столбцами `_sign` и `_version`.
+
+- `_version` — счетчик транзакций. Тип [UInt64](../../sql-reference/data-types/int-uint.md).
+- `_sign` — метка удаления. Тип [Int8](../../sql-reference/data-types/int-uint.md). Возможные значения:
+    - `1` — строка не удалена, 
+    - `-1` — строка удалена.
+
+## Поддержка типов данных {#data_types-support}
+
+| MySQL                   | ClickHouse                                                   |
+|-------------------------|--------------------------------------------------------------|
+| TINY                    | [Int8](../../sql-reference/data-types/int-uint.md)           |
+| SHORT                   | [Int16](../../sql-reference/data-types/int-uint.md)          |
+| INT24                   | [Int32](../../sql-reference/data-types/int-uint.md)          |
+| LONG                    | [UInt32](../../sql-reference/data-types/int-uint.md)         |
+| LONGLONG                | [UInt64](../../sql-reference/data-types/int-uint.md)         |
+| FLOAT                   | [Float32](../../sql-reference/data-types/float.md)           |
+| DOUBLE                  | [Float64](../../sql-reference/data-types/float.md)           |
+| DECIMAL, NEWDECIMAL     | [Decimal](../../sql-reference/data-types/decimal.md)         |
+| DATE, NEWDATE           | [Date](../../sql-reference/data-types/date.md)               |
+| DATETIME, TIMESTAMP     | [DateTime](../../sql-reference/data-types/datetime.md)       |
+| DATETIME2, TIMESTAMP2   | [DateTime64](../../sql-reference/data-types/datetime64.md)   |
+| STRING                  | [String](../../sql-reference/data-types/string.md)           |
+| VARCHAR, VAR_STRING     | [String](../../sql-reference/data-types/string.md)           |
+| BLOB                    | [String](../../sql-reference/data-types/string.md)           |
+
+Другие типы не поддерживаются. Если таблица MySQL содержит столбец другого типа, ClickHouse выдаст исключение "Неподдерживаемый тип данных" ("Unhandled data type") и остановит репликацию.
+
+Тип [Nullable](../../sql-reference/data-types/nullable.md) поддерживается.
+
+## Особенности и рекомендации {#specifics-and-recommendations}
+
+### DDL-запросы {#ddl-queries}
+
+DDL-запросы в MySQL конвертируются в соответствующие DDL-запросы в ClickHouse ([ALTER](../../sql-reference/statements/alter/index.md), [CREATE](../../sql-reference/statements/create/index.md), [DROP](../../sql-reference/statements/drop.md), [RENAME](../../sql-reference/statements/rename.md)). Если ClickHouse не может конвертировать какой-либо DDL-запрос, он его игнорирует.
+
+### Репликация данных {#data-replication}
+
+Данные являются неизменяемыми со стороны пользователя ClickHouse, но автоматически обновляются путём репликации следующих запросов из MySQL:
+
+- Запрос `INSERT` конвертируется в ClickHouse в `INSERT` с `_sign=1`.
+
+- Запрос `DELETE` конвертируется в ClickHouse в `INSERT` с `_sign=-1`.
+
+- Запрос `UPDATE` конвертируется в ClickHouse в `INSERT` с `_sign=-1` и `INSERT` с `_sign=1`.
+
+### Выборка из таблиц движка MaterializeMySQL {#select}
+
+Запрос `SELECT` из таблиц движка `MaterializeMySQL` имеет некоторую специфику:
+
+- Если в запросе `SELECT` напрямую не указан столбец `_version`, то используется модификатор [FINAL](../../sql-reference/statements/select/from.md#select-from-final). Таким образом, выбираются только строки с `MAX(_version)`.
+
+- Если в запросе `SELECT` напрямую не указан столбец `_sign`, то по умолчанию используется `WHERE _sign=1`. Таким образом, удаленные строки не включаются в результирующий набор. 
+
+### Конвертация индексов {#index-conversion}
+
+Секции `PRIMARY KEY` и `INDEX` в MySQL конвертируются в кортежи `ORDER BY` в таблицах ClickHouse.
+
+В таблицах ClickHouse данные физически хранятся в том порядке, который определяется секцией `ORDER BY`. Чтобы физически перегруппировать данные, используйте [материализованные представления](../../sql-reference/statements/create/view.md#materialized).
+
+**Примечание**
+
+- Строки с `_sign=-1` физически не удаляются из таблиц.
+- Каскадные запросы `UPDATE/DELETE` не поддерживаются движком `MaterializeMySQL`.
+- Репликация может быть легко нарушена.
+- Прямые операции изменения данных в таблицах и базах данных `MaterializeMySQL` запрещены.
+
+## Примеры использования {#examples-of-use}
+
+Запросы в MySQL:
+
+``` sql
+mysql> CREATE DATABASE db;
+mysql> CREATE TABLE db.test (a INT PRIMARY KEY, b INT);
+mysql> INSERT INTO db.test VALUES (1, 11), (2, 22);
+mysql> DELETE FROM db.test WHERE a=1;
+mysql> ALTER TABLE db.test ADD COLUMN c VARCHAR(16);
+mysql> UPDATE db.test SET c='Wow!', b=222;
+mysql> SELECT * FROM test;
+```
+
+```text
++---+------+------+ 
+| a |    b |    c |
++---+------+------+ 
+| 2 |  222 | Wow! |
++---+------+------+
+```
+
+База данных в ClickHouse, обмен данными с сервером MySQL:
+
+База данных и созданная таблица:
+
+``` sql
+CREATE DATABASE mysql ENGINE = MaterializeMySQL('localhost:3306', 'db', 'user', '***');
+SHOW TABLES FROM mysql;
+```
+
+``` text
+┌─name─┐
+│ test │
+└──────┘
+```
+
+После вставки данных:
+
+``` sql
+SELECT * FROM mysql.test;
+```
+
+``` text
+┌─a─┬──b─┐ 
+│ 1 │ 11 │ 
+│ 2 │ 22 │ 
+└───┴────┘
+```
+
+После удаления данных, добавления столбца и обновления:
+
+``` sql
+SELECT * FROM mysql.test;
+```
+
+``` text
+┌─a─┬───b─┬─c────┐ 
+│ 2 │ 222 │ Wow! │ 
+└───┴─────┴──────┘
+```
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/database_engines/materialize-mysql/) <!--hide-->

docs/ru/engines/database-engines/mysql.md

@@ -51,6 +51,23 @@ ENGINE = MySQL('host:port', ['database' | database], 'user', 'password')
 
 [Nullable](../../engines/database-engines/mysql.md) поддержан.
 
+## Использование глобальных переменных {#global-variables-support}
+
+Для лучшей совместимости к глобальным переменным можно обращаться в формате MySQL, как `@@identifier`. 
+
+Поддерживаются следующие переменные:
+- `version`
+- `max_allowed_packet`
+
+!!! warning "Предупреждение"
+    В настоящее время эти переменные реализованы только как "заглушки" и не содержат актуальных данных.
+
+Пример:
+
+``` sql
+SELECT @@version;
+```
+
 ## Примеры использования {#primery-ispolzovaniia}
 
 Таблица в MySQL:

docs/ru/engines/table-engines/integrations/embedded-rocksdb.md

@@ -0,0 +1,44 @@
+---
+toc_priority: 6
+toc_title: EmbeddedRocksDB
+---
+
+# Движок EmbeddedRocksDB {#EmbeddedRocksDB-engine}
+
+Этот движок позволяет интегрировать ClickHouse с [rocksdb](http://rocksdb.org/).
+
+## Создание таблицы {#table_engine-EmbeddedRocksDB-creating-a-table}
+
+``` sql
+CREATE TABLE [IF NOT EXISTS] [db.]table_name [ON CLUSTER cluster]
+(
+    name1 [type1] [DEFAULT|MATERIALIZED|ALIAS expr1],
+    name2 [type2] [DEFAULT|MATERIALIZED|ALIAS expr2],
+    ...
+) ENGINE = EmbeddedRocksDB 
+PRIMARY KEY(primary_key_name);
+```
+
+Обязательные параметры:
+
+- `primary_key_name` может быть любое имя столбца из списка столбцов.
+- Указание первичного ключа `primary key` является обязательным. Он будет сериализован в двоичном формате как ключ `rocksdb`. 
+- Поддерживается только один столбец в первичном ключе.
+- Столбцы, которые отличаются от первичного ключа, будут сериализованы в двоичном формате как значение `rockdb` в соответствующем порядке. 
+- Запросы с фильтрацией по ключу `equals` или `in` оптимизируются для поиска по нескольким ключам из `rocksdb`.
+
+Пример:
+
+``` sql
+CREATE TABLE test
+(
+    `key` String,
+    `v1` UInt32,
+    `v2` String,
+    `v3` Float32,
+)
+ENGINE = EmbeddedRocksDB
+PRIMARY KEY key;
+```
+
+[Оригинальная статья](https://clickhouse.tech/docs/ru/operations/table_engines/embedded-rocksdb/) <!--hide-->

docs/ru/engines/table-engines/mergetree-family/mergetree.md

@@ -37,7 +37,10 @@ ORDER BY expr
 [PARTITION BY expr]
 [PRIMARY KEY expr]
 [SAMPLE BY expr]
-[TTL expr [DELETE|TO DISK 'xxx'|TO VOLUME 'xxx'], ...]
+[TTL expr 
+    [DELETE|TO DISK 'xxx'|TO VOLUME 'xxx' [, ...] ]
+    [WHERE conditions] 
+    [GROUP BY key_expr [SET v1 = aggr_func(v1) [, v2 = aggr_func(v2) ...]] ] ] 
 [SETTINGS name=value, ...]
 ```
 
@@ -71,7 +74,7 @@ ORDER BY expr
     
     Выражение должно возвращать столбец `Date` или `DateTime`. Пример: `TTL date + INTERVAL 1 DAY`.   
 
-    Тип правила `DELETE|TO DISK 'xxx'|TO VOLUME 'xxx'` указывает действие, которое будет выполнено с частью, удаление строк (прореживание), перемещение (при выполнении условия для всех строк части) на определённый диск (`TO DISK 'xxx'`) или том (`TO VOLUME 'xxx'`). Поведение по умолчанию соответствует удалению строк (`DELETE`). В списке правил может быть указано только одно выражение с поведением `DELETE`.
+    Тип правила `DELETE|TO DISK 'xxx'|TO VOLUME 'xxx'|GROUP BY` указывает действие, которое будет выполнено с частью: удаление строк (прореживание), перемещение (при выполнении условия для всех строк части) на определённый диск (`TO DISK 'xxx'`) или том (`TO VOLUME 'xxx'`), или агрегирование данных в устаревших строках. Поведение по умолчанию соответствует удалению строк (`DELETE`). В списке правил может быть указано только одно выражение с поведением `DELETE`.
     
     Дополнительные сведения смотрите в разделе [TTL для столбцов и таблиц](#table_engine-mergetree-ttl)
 
@@ -88,6 +91,7 @@ ORDER BY expr
     -   `merge_max_block_size` — максимальное количество строк в блоке для операций слияния. Значение по умолчанию: 8192.
     -   `storage_policy` — политика хранения данных. Смотрите [Хранение данных таблицы на нескольких блочных устройствах](#table_engine-mergetree-multiple-volumes).
     -   `min_bytes_for_wide_part`, `min_rows_for_wide_part` — минимальное количество байт/строк в куске данных для хранения в формате `Wide`. Можно задать одну или обе настройки или не задавать ни одной. Подробнее см. в разделе [Хранение данных](#mergetree-data-storage).
+	-   `max_parts_in_total` — максимальное количество кусков во всех партициях.
 	-   `max_compress_block_size` — максимальный размер блоков несжатых данных перед сжатием для записи в таблицу. Вы также можете задать этот параметр в глобальных настройках (смотрите [max_compress_block_size](../../../operations/settings/settings.md#max-compress-block-size)). Настройка, которая задается при создании таблицы, имеет более высокий приоритет, чем глобальная.
 	-   `min_compress_block_size` — минимальный размер блоков несжатых данных, необходимых для сжатия при записи следующей засечки. Вы также можете задать этот параметр в глобальных настройках (смотрите [min_compress_block_size](../../../operations/settings/settings.md#min-compress-block-size)). Настройка, которая задается при создании таблицы, имеет более высокий приоритет, чем глобальная.
 
@@ -442,16 +446,28 @@ ALTER TABLE example_table
 Для таблицы можно задать одно выражение для устаревания данных, а также несколько выражений, по срабатывании которых данные переместятся на [некоторый диск или том](#table_engine-mergetree-multiple-volumes). Когда некоторые данные в таблице устаревают, ClickHouse удаляет все соответствующие строки.
 
 ``` sql
-TTL expr [DELETE|TO DISK 'aaa'|TO VOLUME 'bbb'], ...
+TTL expr 
+    [DELETE|TO DISK 'xxx'|TO VOLUME 'xxx'][, DELETE|TO DISK 'aaa'|TO VOLUME 'bbb'] ...
+    [WHERE conditions] 
+    [GROUP BY key_expr [SET v1 = aggr_func(v1) [, v2 = aggr_func(v2) ...]] ] 
 ```
 
 За каждым TTL выражением может следовать тип действия, которое выполняется после достижения времени, соответствующего результату TTL выражения:
 
 -   `DELETE` - удалить данные (действие по умолчанию);
 -   `TO DISK 'aaa'` - переместить данные на диск `aaa`;
--   `TO VOLUME 'bbb'` - переместить данные на том `bbb`.
+-   `TO VOLUME 'bbb'` - переместить данные на том `bbb`;
+-   `GROUP BY` -  агрегировать данные.
 
-Примеры:
+В секции `WHERE` можно задать условие удаления или агрегирования устаревших строк (для перемещения условие `WHERE` не применимо).
+
+Колонки, по которым агрегируются данные в `GROUP BY`, должны являться префиксом первичного ключа таблицы. 
+
+Если колонка не является частью выражения `GROUP BY` и не задается напрямую в секции `SET`, в результирующих строках она будет содержать случайное значение, взятое из одной из сгруппированных строк (как будто к ней применяется агрегирующая функция `any`).
+
+**Примеры**
+
+Создание таблицы с TTL: 
 
 ``` sql
 CREATE TABLE example_table
@@ -467,13 +483,43 @@ TTL d + INTERVAL 1 MONTH [DELETE],
     d + INTERVAL 2 WEEK TO DISK 'bbb';
 ```
 
-Изменение TTL
+Изменение TTL:
 
 ``` sql
 ALTER TABLE example_table
     MODIFY TTL d + INTERVAL 1 DAY;
 ```
 
+Создание таблицы, в которой строки устаревают через месяц. Устаревшие строки удаляются, если дата выпадает на понедельник:
+
+``` sql
+CREATE TABLE table_with_where
+(
+    d DateTime, 
+    a Int
+)
+ENGINE = MergeTree
+PARTITION BY toYYYYMM(d)
+ORDER BY d
+TTL d + INTERVAL 1 MONTH DELETE WHERE toDayOfWeek(d) = 1;
+```
+
+Создание таблицы, где устаревшие строки агрегируются. В результирующих строках колонка `x` содержит максимальное значение по сгруппированным строкам, `y` — минимальное значение, а `d` — случайное значение из одной из сгуппированных строк.
+
+``` sql
+CREATE TABLE table_for_aggregation
+(
+    d DateTime, 
+    k1 Int, 
+    k2 Int, 
+    x Int, 
+    y Int
+)
+ENGINE = MergeTree
+ORDER BY k1, k2
+TTL d + INTERVAL 1 MONTH GROUP BY k1, k2 SET x = max(x), y = min(y);
+```
+
 **Удаление данных**
 
 Данные с истекшим TTL удаляются, когда ClickHouse мёржит куски данных.