Merge remote-tracking branch 'origin' into integration-2

2024-11-21 15:12:02 +00:00 · 2021-04-28 17:23:33 +03:00 · 2021-04-28 17:23:33 +03:00 · a87fe5e1bc
commit a87fe5e1bc
parent 30b05fec42 c508868570
282 changed files with 2793 additions and 3196 deletions
--- a/.github/ISSUE_TEMPLATE/40_bug-report.md
+++ b/.github/ISSUE_TEMPLATE/40_bug-report.md
@ -7,7 +7,7 @@ assignees: ''

 ---

-(you don't have to strictly follow this form)
+You have to provide the following information whenever possible.

 **Describe the bug**
 A clear and concise description of what works not as it is supposed to.
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -167,6 +167,7 @@ endif ()

 # If turned `ON`, assumes the user has either the system GTest library or the bundled one.
 option(ENABLE_TESTS "Provide unit_test_dbms target with Google.Test unit tests" ON)
+option(ENABLE_EXAMPLES "Build all example programs in 'examples' subdirectories" OFF)

 if (OS_LINUX AND NOT UNBUNDLED AND MAKE_STATIC_LIBRARIES AND NOT SPLIT_SHARED_LIBRARIES AND CMAKE_VERSION VERSION_GREATER "3.9.0")
    # Only for Linux, x86_64.
--- a/contrib/boost
+++ b/contrib/boost
@ -1 +1 @@
-Subproject commit a8d43d3142cc6b26fc55bec33f7f6edb1156ab7a
+Subproject commit 9f0ff347e50429686604002d8ad1fd07515c4f31
--- a/contrib/cyrus-sasl
+++ b/contrib/cyrus-sasl
@ -1 +1 @@
-Subproject commit 9995bf9d8e14f58934d9313ac64f13780d6dd3c9
+Subproject commit e6466edfd638cc5073debe941c53345b18a09512
--- a/docker/test/performance-comparison/compare.sh
+++ b/docker/test/performance-comparison/compare.sh
@ -1019,6 +1019,7 @@ done
 wait

 # Create per-query flamegraphs
+touch report/query-files.txt
 IFS=$'\n'
 for version in {right,left}
 do
@ -1209,6 +1210,12 @@ function upload_results
            /^metric/ { print old_sha, new_sha, $2, $3 }' \
        | "${client[@]}" --query "INSERT INTO run_attributes_v1 FORMAT TSV"

+    # Grepping numactl results from log is too crazy, I'll just call it again.
+    "${client[@]}" --query "INSERT INTO run_attributes_v1 FORMAT TSV" <<EOF
+$REF_SHA	$SHA_TO_TEST	$(numactl --show | sed -n 's/^cpubind:[[:space:]]\+/numactl-cpubind	/p')
+$REF_SHA	$SHA_TO_TEST	$(numactl --hardware | sed -n 's/^available:[[:space:]]\+/numactl-available	/p')
+EOF
+
    set -x
 }

--- a/docker/test/performance-comparison/perf.py
+++ b/docker/test/performance-comparison/perf.py
@ -81,7 +81,10 @@ def substitute_parameters(query_templates, other_templates = []):
    query_results = []
    other_results = [[]] * (len(other_templates))
    for i, q in enumerate(query_templates):
-        keys = set(n for _, n, _, _ in string.Formatter().parse(q) if n)
+        # We need stable order of keys here, so that the order of substitutions
+        # is always the same, and the query indexes are consistent across test
+        # runs.
+        keys = sorted(set(n for _, n, _, _ in string.Formatter().parse(q) if n))
        values = [available_parameters[k] for k in keys]
        combos = itertools.product(*values)
        for c in combos:
--- a/docker/test/sqlancer/Dockerfile
+++ b/docker/test/sqlancer/Dockerfile
@ -2,6 +2,7 @@
 FROM ubuntu:20.04

 RUN apt-get update --yes && env DEBIAN_FRONTEND=noninteractive apt-get install wget unzip git openjdk-14-jdk maven python3 --yes --no-install-recommends
+
 RUN wget https://github.com/sqlancer/sqlancer/archive/master.zip -O /sqlancer.zip
 RUN mkdir /sqlancer && \
 	cd /sqlancer && \
--- a/docs/en/sql-reference/aggregate-functions/reference/max.md
+++ b/docs/en/sql-reference/aggregate-functions/reference/max.md
@ -4,4 +4,21 @@ toc_priority: 3

 # max {#agg_function-max}

-Calculates the maximum.
+Aggregate function that calculates the maximum across a group of values.
+
+Example:
+
+```
+SELECT max(salary) FROM employees;
+```
+
+```
+SELECT department, max(salary) FROM employees GROUP BY department;
+```
+
+If you need non-aggregate function to choose a maximum of two values, see `greatest`:
+
+```
+SELECT greatest(a, b) FROM table;
+```
+
--- a/docs/en/sql-reference/aggregate-functions/reference/min.md
+++ b/docs/en/sql-reference/aggregate-functions/reference/min.md
@ -4,4 +4,20 @@ toc_priority: 2

 ## min {#agg_function-min}

-Calculates the minimum.
+Aggregate function that calculates the minimum across a group of values.
+
+Example:
+
+```
+SELECT min(salary) FROM employees;
+```
+
+```
+SELECT department, min(salary) FROM employees GROUP BY department;
+```
+
+If you need non-aggregate function to choose a minimum of two values, see `least`:
+
+```
+SELECT least(a, b) FROM table;
+```
--- a/docs/en/sql-reference/data-types/datetime.md
+++ b/docs/en/sql-reference/data-types/datetime.md
@ -23,7 +23,7 @@ The point in time is saved as a [Unix timestamp](https://en.wikipedia.org/wiki/U

 Timezone agnostic unix timestamp is stored in tables, and the timezone is used to transform it to text format or back during data import/export or to make calendar calculations on the values (example: `toDate`, `toHour` functions et cetera). The time zone is not stored in the rows of the table (or in resultset), but is stored in the column metadata.

-A list of supported time zones can be found in the [IANA Time Zone Database](https://www.iana.org/time-zones) and also can be queried by `SELECT * FROM system.time_zones`.
+A list of supported time zones can be found in the [IANA Time Zone Database](https://www.iana.org/time-zones) and also can be queried by `SELECT * FROM system.time_zones`. [The list](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) is also available at Wikipedia.

 You can explicitly set a time zone for `DateTime`-type columns when creating a table. Example: `DateTime('UTC')`. If the time zone isn’t set, ClickHouse uses the value of the [timezone](../../operations/server-configuration-parameters/settings.md#server_configuration_parameters-timezone) parameter in the server settings or the operating system settings at the moment of the ClickHouse server start.

--- a/docs/en/sql-reference/functions/date-time-functions.md
+++ b/docs/en/sql-reference/functions/date-time-functions.md
@ -134,6 +134,46 @@ Result:
 └───────────────────┘
 ```

+## timeZoneOffset {#timezoneoffset}
+
+Returns a timezone offset in seconds from [UTC](https://en.wikipedia.org/wiki/Coordinated_Universal_Time). The function takes into account [daylight saving time](https://en.wikipedia.org/wiki/Daylight_saving_time) and historical timezone changes at the specified date and time.
+[IANA timezone database](https://www.iana.org/time-zones) is used to calculate the offset.
+
+**Syntax**
+
+``` sql
+timeZoneOffset(value)
+```
+
+Alias: `timezoneOffset`.
+
+**Arguments**
+
+-   `value` — Date and time. [DateTime](../../sql-reference/data-types/datetime.md) or [DateTime64](../../sql-reference/data-types/datetime64.md). 
+
+**Returned value**
+
+-   Offset from UTC in seconds. 
+
+Type: [Int32](../../sql-reference/data-types/int-uint.md).
+
+**Example**
+
+Query:
+
+``` sql
+SELECT toDateTime('2021-04-21 10:20:30', 'America/New_York') AS Time, toTypeName(Time) AS Type,
+       timeZoneOffset(Time) AS Offset_in_seconds, (Offset_in_seconds / 3600) AS Offset_in_hours;
+```
+
+Result:
+
+``` text
+┌────────────────Time─┬─Type─────────────────────────┬─Offset_in_seconds─┬─Offset_in_hours─┐
+│ 2021-04-21 10:20:30 │ DateTime('America/New_York') │            -14400 │              -4 │
+└─────────────────────┴──────────────────────────────┴───────────────────┴─────────────────┘
+```
+
 ## toYear {#toyear}

 Converts a date or date with time to a UInt16 number containing the year number (AD).
--- a/docs/ru/sql-reference/aggregate-functions/reference/max.md
+++ b/docs/ru/sql-reference/aggregate-functions/reference/max.md
@ -1,8 +0,0 @@
---
-toc_priority: 3
---
-
-# max {#agg_function-max}
-
-Вычисляет максимум.
-
--- a/docs/ru/sql-reference/aggregate-functions/reference/max.md
+++ b/docs/ru/sql-reference/aggregate-functions/reference/max.md
@ -0,0 +1 @@
+../../../../en/sql-reference/aggregate-functions/reference/max.md
--- a/docs/ru/sql-reference/aggregate-functions/reference/min.md
+++ b/docs/ru/sql-reference/aggregate-functions/reference/min.md
@ -1,8 +0,0 @@
---
-toc_priority: 2
---
-
-## min {#agg_function-min}
-
-Вычисляет минимум.
-
--- a/docs/ru/sql-reference/aggregate-functions/reference/min.md
+++ b/docs/ru/sql-reference/aggregate-functions/reference/min.md
@ -0,0 +1 @@
+../../../../en/sql-reference/aggregate-functions/reference/min.md
--- a/docs/ru/sql-reference/data-types/datetime.md
+++ b/docs/ru/sql-reference/data-types/datetime.md
@ -20,8 +20,7 @@ DateTime([timezone])
 ## Использование {#ispolzovanie}

 Момент времени сохраняется как [Unix timestamp](https://ru.wikipedia.org/wiki/Unix-%D0%B2%D1%80%D0%B5%D0%BC%D1%8F), независимо от часового пояса и переходов на летнее/зимнее время. Дополнительно, тип `DateTime` позволяет хранить часовой пояс, единый для всей колонки, который влияет на то, как будут отображаться значения типа `DateTime` в текстовом виде и как будут парситься значения заданные в виде строк (‘2020-01-01 05:00:01’). Часовой пояс не хранится в строках таблицы (выборки), а хранится в метаданных колонки.
-Список поддерживаемых временных зон можно найти в [IANA Time Zone Database](https://www.iana.org/time-zones).
-Пакет `tzdata`, содержащий [базу данных часовых поясов IANA](https://www.iana.org/time-zones), должен быть установлен в системе. Используйте команду `timedatectl list-timezones` для получения списка часовых поясов, известных локальной системе.
+Список поддерживаемых часовых поясов можно найти в [IANA Time Zone Database](https://www.iana.org/time-zones) или получить из базы данных, выполнив запрос `SELECT * FROM system.time_zones`. Также [список](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) есть в Википедии.

 Часовой пояс для столбца типа `DateTime` можно в явном виде установить при создании таблицы. Если часовой пояс не установлен, то ClickHouse использует значение параметра [timezone](../../sql-reference/data-types/datetime.md#server_configuration_parameters-timezone), установленное в конфигурации сервера или в настройках операционной системы на момент запуска сервера.

--- a/docs/ru/sql-reference/functions/date-time-functions.md
+++ b/docs/ru/sql-reference/functions/date-time-functions.md
@ -134,6 +134,46 @@ SELECT timezoneOf(now());
 └───────────────────┘
 ```

+## timeZoneOffset {#timezoneoffset}
+
+Возвращает смещение часового пояса в секундах от [UTC](https://ru.wikipedia.org/wiki/Всемирное_координированное_время). Функция учитывает [летнее время](https://ru.wikipedia.org/wiki/Летнее_время) и исторические изменения часовых поясов, которые действовали на указанную дату.
+Для вычисления смещения используется информация из [базы данных IANA](https://www.iana.org/time-zones).
+
+**Синтаксис**
+
+``` sql
+timeZoneOffset(value)
+```
+
+Псевдоним: `timezoneOffset`. 
+
+**Аргументы**
+
+-   `value` — Дата с временем. [DateTime](../../sql-reference/data-types/datetime.md) or [DateTime64](../../sql-reference/data-types/datetime64.md). 
+
+**Возвращаемое значение**
+
+-   Смещение в секундах от UTC. 
+
+Тип: [Int32](../../sql-reference/data-types/int-uint.md).
+
+**Пример**
+
+Запрос:
+
+``` sql
+SELECT toDateTime('2021-04-21 10:20:30', 'Europe/Moscow') AS Time, toTypeName(Time) AS Type,
+       timeZoneOffset(Time) AS Offset_in_seconds, (Offset_in_seconds / 3600) AS Offset_in_hours;
+```
+
+Результат:
+
+``` text
+┌────────────────Time─┬─Type──────────────────────┬─Offset_in_seconds─┬─Offset_in_hours─┐
+│ 2021-04-21 10:20:30 │ DateTime('Europe/Moscow') │             10800 │               3 │
+└─────────────────────┴───────────────────────────┴───────────────────┴─────────────────┘
+```
+
 ## toYear {#toyear}

 Переводит дату или дату-с-временем в число типа UInt16, содержащее номер года (AD).
--- a/src/AggregateFunctions/AggregateFunctionIf.h
+++ b/src/AggregateFunctions/AggregateFunctionIf.h
@ -113,6 +113,16 @@ public:
        nested_func->merge(place, rhs, arena);
    }

+    void mergeBatch(
+        size_t batch_size,
+        AggregateDataPtr * places,
+        size_t place_offset,
+        const AggregateDataPtr * rhs,
+        Arena * arena) const override
+    {
+        nested_func->mergeBatch(batch_size, places, place_offset, rhs, arena);
+    }
+
    void serialize(ConstAggregateDataPtr __restrict place, WriteBuffer & buf) const override
    {
        nested_func->serialize(place, buf);
--- a/src/AggregateFunctions/AggregateFunctionOrFill.h
+++ b/src/AggregateFunctions/AggregateFunctionOrFill.h
@ -196,6 +196,18 @@ public:
        place[size_of_data] |= rhs[size_of_data];
    }

+    void mergeBatch(
+        size_t batch_size,
+        AggregateDataPtr * places,
+        size_t place_offset,
+        const AggregateDataPtr * rhs,
+        Arena * arena) const override
+    {
+        nested_function->mergeBatch(batch_size, places, place_offset, rhs, arena);
+        for (size_t i = 0; i < batch_size; ++i)
+            (places[i] + place_offset)[size_of_data] |= rhs[i][size_of_data];
+    }
+
    void serialize(
        ConstAggregateDataPtr place,
        WriteBuffer & buf) const override
--- a/src/AggregateFunctions/CMakeLists.txt
+++ b/src/AggregateFunctions/CMakeLists.txt
@ -24,6 +24,6 @@ list(REMOVE_ITEM clickhouse_aggregate_functions_headers
 add_library(clickhouse_aggregate_functions ${clickhouse_aggregate_functions_sources})
 target_link_libraries(clickhouse_aggregate_functions PRIVATE dbms PUBLIC ${CITYHASH_LIBRARIES})

-if(ENABLE_TESTS)
-    add_subdirectory(tests)
+if(ENABLE_EXAMPLES)
+    add_subdirectory(examples)
 endif()
--- a/src/AggregateFunctions/IAggregateFunction.h
+++ b/src/AggregateFunctions/IAggregateFunction.h
@ -153,6 +153,13 @@ public:
        Arena * arena,
        ssize_t if_argument_pos = -1) const = 0;

+    virtual void mergeBatch(
+        size_t batch_size,
+        AggregateDataPtr * places,
+        size_t place_offset,
+        const AggregateDataPtr * rhs,
+        Arena * arena) const = 0;
+
    /** The same for single place.
      */
    virtual void addBatchSinglePlace(
@ -279,6 +286,18 @@ public:
        }
    }

+    void mergeBatch(
+        size_t batch_size,
+        AggregateDataPtr * places,
+        size_t place_offset,
+        const AggregateDataPtr * rhs,
+        Arena * arena) const override
+    {
+        for (size_t i = 0; i < batch_size; ++i)
+            if (places[i])
+                static_cast<const Derived *>(this)->merge(places[i] + place_offset, rhs[i], arena);
+    }
+
    void addBatchSinglePlace(
        size_t batch_size, AggregateDataPtr place, const IColumn ** columns, Arena * arena, ssize_t if_argument_pos = -1) const override
    {
--- a/src/AggregateFunctions/StatCommon.h
+++ b/src/AggregateFunctions/StatCommon.h
@ -11,6 +11,11 @@
 namespace DB
 {

+namespace ErrorCodes
+{
+    extern const int BAD_ARGUMENTS;
+}
+
 template <typename F>
 static Float64 integrateSimpson(Float64 a, Float64 b, F && func)
 {
@ -48,6 +53,11 @@ std::pair<RanksArray, Float64> computeRanksAndTieCorrection(const Values & value
            ++right;
        auto adjusted = (left + right + 1.) / 2.;
        auto count_equal = right - left;
+
+        /// Scipy implementation throws exception in this case too.
+        if (count_equal == size)
+            throw Exception("All numbers in both samples are identical", ErrorCodes::BAD_ARGUMENTS);
+
        tie_numenator += std::pow(count_equal, 3) - count_equal;
        for (size_t iter = left; iter < right; ++iter)
            out[indexes[iter]] = adjusted;
--- a/src/AggregateFunctions/examples/CMakeLists.txt
+++ b/src/AggregateFunctions/examples/CMakeLists.txt
--- a/src/AggregateFunctions/examples/quantile-t-digest.cpp
+++ b/src/AggregateFunctions/examples/quantile-t-digest.cpp
--- a/src/Client/CMakeLists.txt
+++ b/src/Client/CMakeLists.txt
@ -1 +1,3 @@
-add_subdirectory(tests)
+if (ENABLE_EXAMPLES)
+    add_subdirectory(examples)
+endif()
--- a/src/Client/examples/CMakeLists.txt
+++ b/src/Client/examples/CMakeLists.txt
--- a/src/Client/examples/test_connect.cpp
+++ b/src/Client/examples/test_connect.cpp
--- a/src/Columns/CMakeLists.txt
+++ b/src/Columns/CMakeLists.txt
@ -1,3 +1,3 @@
-if (ENABLE_TESTS)
-    add_subdirectory (tests)
+if (ENABLE_EXAMPLES)
+    add_subdirectory (examples)
 endif ()
--- a/src/Columns/examples/CMakeLists.txt
+++ b/src/Columns/examples/CMakeLists.txt
--- a/src/Common/CMakeLists.txt
+++ b/src/Common/CMakeLists.txt
@ -3,6 +3,6 @@ add_subdirectory(StringUtils)
 #add_subdirectory(ZooKeeper)
 #add_subdirectory(ConfigProcessor)

-if (ENABLE_TESTS)
-    add_subdirectory (tests)
-endif ()
+if (ENABLE_EXAMPLES)
+    add_subdirectory(examples)
+endif()
--- a/src/Common/JSONBuilder.cpp
+++ b/src/Common/JSONBuilder.cpp
@ -0,0 +1,99 @@
+#include <Common/JSONBuilder.h>
+#include <IO/WriteHelpers.h>
+#include <Common/typeid_cast.h>
+
+namespace DB::JSONBuilder
+{
+
+static bool isArrayOrMap(const IItem & item)
+{
+    return typeid_cast<const JSONArray *>(&item) || typeid_cast<const JSONMap *>(&item);
+}
+
+static bool isSimpleArray(const std::vector<ItemPtr> & values)
+{
+    for (const auto & value : values)
+        if (isArrayOrMap(*value))
+            return false;
+
+    return true;
+}
+
+void JSONString::format(const FormatSettings & settings, FormatContext & context)
+{
+    writeJSONString(value, context.out, settings.settings);
+}
+
+void JSONBool::format(const FormatSettings &, FormatContext & context)
+{
+    writeString(value ? "true" : "false", context.out);
+}
+
+void JSONArray::format(const FormatSettings & settings, FormatContext & context)
+{
+    writeChar('[', context.out);
+
+    context.offset += settings.indent;
+
+    bool single_row = settings.print_simple_arrays_in_single_row && isSimpleArray(values);
+    bool first = true;
+
+    for (const auto & value : values)
+    {
+        if (!first)
+            writeChar(',', context.out);
+
+        if (!single_row)
+        {
+            writeChar('\n', context.out);
+            writeChar(' ', context.offset, context.out);
+        }
+        else if (!first)
+            writeChar(' ', context.out);
+
+        first = false;
+        value->format(settings, context);
+    }
+
+    context.offset -= settings.indent;
+
+    if (!single_row)
+    {
+        writeChar('\n', context.out);
+        writeChar(' ', context.offset, context.out);
+    }
+
+    writeChar(']', context.out);
+}
+
+void JSONMap::format(const FormatSettings & settings, FormatContext & context)
+{
+    writeChar('{', context.out);
+
+    context.offset += settings.indent;
+
+    bool first = true;
+
+    for (const auto & value : values)
+    {
+        if (!first)
+            writeChar(',', context.out);
+        first = false;
+
+        writeChar('\n', context.out);
+        writeChar(' ', context.offset, context.out);
+        writeJSONString(value.key, context.out, settings.settings);
+
+        writeChar(':', context.out);
+        writeChar(' ', context.out);
+        value.value->format(settings, context);
+    }
+
+    context.offset -= settings.indent;
+
+    writeChar('\n', context.out);
+    writeChar(' ', context.offset, context.out);
+    writeChar('}', context.out);
+}
+
+}
--- a/src/Common/JSONBuilder.h
+++ b/src/Common/JSONBuilder.h
@ -0,0 +1,111 @@
+#pragma once
+#include <type_traits>
+#include <vector>
+#include <IO/WriteBuffer.h>
+#include <Formats/FormatSettings.h>
+#include <IO/WriteHelpers.h>
+
+namespace DB::JSONBuilder
+{
+
+struct FormatSettings
+{
+    const DB::FormatSettings & settings;
+    size_t indent = 2;
+    bool print_simple_arrays_in_single_row = true;
+};
+
+struct FormatContext
+{
+    WriteBuffer & out;
+    size_t offset = 0;
+};
+
+class IItem
+{
+public:
+    virtual ~IItem() = default;
+    virtual void format(const FormatSettings & settings, FormatContext & context) = 0;
+};
+
+using ItemPtr = std::unique_ptr<IItem>;
+
+class JSONString : public IItem
+{
+public:
+    explicit JSONString(std::string value_) : value(std::move(value_)) {}
+    void format(const FormatSettings & settings, FormatContext & context) override;
+
+private:
+    std::string value;
+};
+
+template <typename T>
+class JSONNumber : public IItem
+{
+public:
+    explicit JSONNumber(T value_) : value(value_)
+    {
+        static_assert(std::is_arithmetic_v<T>, "JSONNumber support only numeric types");
+    }
+
+    void format(const FormatSettings & settings, FormatContext & context) override
+    {
+        writeJSONNumber(value, context.out, settings.settings);
+    }
+
+private:
+    T value;
+};
+
+class JSONBool : public IItem
+{
+public:
+    explicit JSONBool(bool value_) : value(std::move(value_)) {}
+    void format(const FormatSettings & settings, FormatContext & context) override;
+
+private:
+    bool value;
+};
+
+class JSONArray : public IItem
+{
+public:
+    void add(ItemPtr value) { values.push_back(std::move(value)); }
+    void add(std::string value) { add(std::make_unique<JSONString>(std::move(value))); }
+    void add(const char * value) { add(std::make_unique<JSONString>(value)); }
+    void add(bool value) { add(std::make_unique<JSONBool>(std::move(value))); }
+
+    template <typename T, std::enable_if_t<std::is_arithmetic<T>::value, bool> = true>
+    void add(T value) { add(std::make_unique<JSONNumber<T>>(value)); }
+
+    void format(const FormatSettings & settings, FormatContext & context) override;
+
+private:
+    std::vector<ItemPtr> values;
+};
+
+class JSONMap : public IItem
+{
+    struct Pair
+    {
+        std::string key;
+        ItemPtr value;
+    };
+
+public:
+    void add(std::string key, ItemPtr value) { values.emplace_back(Pair{.key = std::move(key), .value = std::move(value)}); }
+    void add(std::string key, std::string value) { add(std::move(key), std::make_unique<JSONString>(std::move(value))); }
+    void add(std::string key, const char * value) { add(std::move(key), std::make_unique<JSONString>(value)); }
+    void add(std::string key, bool value) { add(std::move(key), std::make_unique<JSONBool>(std::move(value))); }
+
+    template <typename T, std::enable_if_t<std::is_arithmetic<T>::value, bool> = true>
+    void add(std::string key, T value) { add(std::move(key), std::make_unique<JSONNumber<T>>(value)); }
+
+    void format(const FormatSettings & settings, FormatContext & context) override;
+
+private:
+    std::vector<Pair> values;
+};
+
+}
--- a/src/Common/StatusInfo.cpp
+++ b/src/Common/StatusInfo.cpp
@ -1,5 +1,5 @@
 #include <Common/StatusInfo.h>
-#include <Interpreters/ExternalLoader.h>
+#include <Common/ExternalLoaderStatus.h>

 /// Available status. Add something here as you wish.
 #define APPLY_FOR_STATUS(M) \
--- a/src/Common/ZooKeeper/CMakeLists.txt
+++ b/src/Common/ZooKeeper/CMakeLists.txt
@ -6,6 +6,6 @@ add_library(clickhouse_common_zookeeper ${clickhouse_common_zookeeper_headers} $

 target_link_libraries (clickhouse_common_zookeeper PUBLIC clickhouse_common_io common PRIVATE string_utils)

-if (ENABLE_TESTS)
-    add_subdirectory (tests)
-endif ()
+if (ENABLE_EXAMPLES)
+    add_subdirectory(examples)
+endif()
--- a/src/Common/ZooKeeper/examples/CMakeLists.txt
+++ b/src/Common/ZooKeeper/examples/CMakeLists.txt
--- a/src/Common/ZooKeeper/examples/zk_many_watches_reconnect.cpp
+++ b/src/Common/ZooKeeper/examples/zk_many_watches_reconnect.cpp
--- a/src/Common/ZooKeeper/examples/zkutil_test_async.cpp
+++ b/src/Common/ZooKeeper/examples/zkutil_test_async.cpp
--- a/src/Common/ZooKeeper/examples/zkutil_test_commands.cpp
+++ b/src/Common/ZooKeeper/examples/zkutil_test_commands.cpp
--- a/src/Common/ZooKeeper/examples/zkutil_test_commands_new_lib.cpp
+++ b/src/Common/ZooKeeper/examples/zkutil_test_commands_new_lib.cpp
--- a/src/Common/ZooKeeper/examples/zookeeper_impl.cpp
+++ b/src/Common/ZooKeeper/examples/zookeeper_impl.cpp
--- a/src/Common/examples/CMakeLists.txt
+++ b/src/Common/examples/CMakeLists.txt
@ -35,9 +35,6 @@ target_include_directories(radix_sort SYSTEM PRIVATE ${PDQSORT_INCLUDE_DIR})
 add_executable (arena_with_free_lists arena_with_free_lists.cpp)
 target_link_libraries (arena_with_free_lists PRIVATE dbms)

-add_executable (pod_array pod_array.cpp)
-target_link_libraries (pod_array PRIVATE clickhouse_common_io)
-
 add_executable (lru_hash_map_perf lru_hash_map_perf.cpp)
 target_link_libraries (lru_hash_map_perf PRIVATE clickhouse_common_io)

--- a/src/Common/examples/arena_with_free_lists.cpp
+++ b/src/Common/examples/arena_with_free_lists.cpp
--- a/src/Common/examples/array_cache.cpp
+++ b/src/Common/examples/array_cache.cpp
--- a/src/Common/examples/auto_array.cpp
+++ b/src/Common/examples/auto_array.cpp
--- a/src/Common/examples/average.cpp
+++ b/src/Common/examples/average.cpp
--- a/src/Common/examples/chaos_sanitizer.cpp
+++ b/src/Common/examples/chaos_sanitizer.cpp
--- a/src/Common/examples/compact_array.cpp
+++ b/src/Common/examples/compact_array.cpp
--- a/src/Common/examples/cow_columns.cpp
+++ b/src/Common/examples/cow_columns.cpp
--- a/src/Common/examples/cow_compositions.cpp
+++ b/src/Common/examples/cow_compositions.cpp
--- a/src/Common/examples/hashes_test.cpp
+++ b/src/Common/examples/hashes_test.cpp
--- a/src/Common/examples/int_hashes_perf.cpp
+++ b/src/Common/examples/int_hashes_perf.cpp
--- a/src/Common/examples/integer_hash_tables_and_hashes.cpp
+++ b/src/Common/examples/integer_hash_tables_and_hashes.cpp
--- a/src/Common/examples/lru_hash_map_perf.cpp
+++ b/src/Common/examples/lru_hash_map_perf.cpp
--- a/src/Common/examples/memory_statistics_os_perf.cpp
+++ b/src/Common/examples/memory_statistics_os_perf.cpp
--- a/src/Common/examples/parallel_aggregation.cpp
+++ b/src/Common/examples/parallel_aggregation.cpp
--- a/src/Common/examples/parallel_aggregation2.cpp
+++ b/src/Common/examples/parallel_aggregation2.cpp
--- a/src/Common/examples/procfs_metrics_provider_perf.cpp
+++ b/src/Common/examples/procfs_metrics_provider_perf.cpp
--- a/src/Common/examples/radix_sort.cpp
+++ b/src/Common/examples/radix_sort.cpp
--- a/src/Common/examples/shell_command_inout.cpp
+++ b/src/Common/examples/shell_command_inout.cpp
--- a/src/Common/examples/simple_cache.cpp
+++ b/src/Common/examples/simple_cache.cpp
--- a/src/Common/examples/sip_hash_perf.cpp
+++ b/src/Common/examples/sip_hash_perf.cpp
--- a/src/Common/examples/small_table.cpp
+++ b/src/Common/examples/small_table.cpp
--- a/src/Common/examples/space_saving.cpp
+++ b/src/Common/examples/space_saving.cpp
--- a/src/Common/examples/stopwatch.cpp
+++ b/src/Common/examples/stopwatch.cpp
--- a/src/Common/examples/symbol_index.cpp
+++ b/src/Common/examples/symbol_index.cpp
--- a/src/Common/examples/thread_creation_latency.cpp
+++ b/src/Common/examples/thread_creation_latency.cpp
--- a/src/Common/tests/gtest_pod_array.cpp
+++ b/src/Common/tests/gtest_pod_array.cpp
@ -4,6 +4,419 @@

 using namespace DB;

+
+TEST(Common, PODArrayBasicMove)
+{
+    using namespace DB;
+
+    static constexpr size_t initial_bytes = 32;
+    using Array = PODArray<UInt64, initial_bytes,
+        AllocatorWithStackMemory<Allocator<false>, initial_bytes>>;
+
+    {
+        Array arr;
+        Array arr2;
+        arr2 = std::move(arr);
+    }
+
+    {
+        Array arr;
+
+        arr.push_back(1);
+        arr.push_back(2);
+        arr.push_back(3);
+
+        Array arr2;
+
+        arr2 = std::move(arr);
+
+        ASSERT_EQ(arr2.size(), 3);
+        ASSERT_EQ(arr2[0], 1);
+        ASSERT_EQ(arr2[1], 2);
+        ASSERT_EQ(arr2[2], 3);
+
+        arr = std::move(arr2);
+
+        ASSERT_EQ(arr.size(), 3);
+        ASSERT_EQ(arr[0], 1);
+        ASSERT_EQ(arr[1], 2);
+        ASSERT_EQ(arr[2], 3);
+    }
+
+    {
+        Array arr;
+
+        arr.push_back(1);
+        arr.push_back(2);
+        arr.push_back(3);
+        arr.push_back(4);
+        arr.push_back(5);
+
+        Array arr2;
+
+        arr2 = std::move(arr);
+
+        ASSERT_EQ(arr2.size(), 5);
+        ASSERT_EQ(arr2[0], 1);
+        ASSERT_EQ(arr2[1], 2);
+        ASSERT_EQ(arr2[2], 3);
+        ASSERT_EQ(arr2[3], 4);
+        ASSERT_EQ(arr2[4], 5);
+
+        arr = std::move(arr2);
+
+        ASSERT_EQ(arr.size(), 5);
+        ASSERT_EQ(arr[0], 1);
+        ASSERT_EQ(arr[1], 2);
+        ASSERT_EQ(arr[2], 3);
+        ASSERT_EQ(arr[3], 4);
+        ASSERT_EQ(arr[4], 5);
+    }
+
+    {
+        Array arr;
+
+        arr.push_back(1);
+        arr.push_back(2);
+        arr.push_back(3);
+
+        Array arr2;
+
+        arr2.push_back(4);
+        arr2.push_back(5);
+        arr2.push_back(6);
+        arr2.push_back(7);
+
+        arr2 = std::move(arr);
+
+        ASSERT_EQ(arr2.size(), 3);
+        ASSERT_EQ(arr2[0], 1);
+        ASSERT_EQ(arr2[1], 2);
+        ASSERT_EQ(arr2[2], 3);
+    }
+
+    {
+        Array arr;
+
+        arr.push_back(1);
+        arr.push_back(2);
+        arr.push_back(3);
+
+        Array arr2;
+
+        arr2.push_back(4);
+        arr2.push_back(5);
+        arr2.push_back(6);
+        arr2.push_back(7);
+        arr2.push_back(8);
+
+        arr = std::move(arr2);
+
+        ASSERT_EQ(arr.size(), 5);
+        ASSERT_EQ(arr[0], 4);
+        ASSERT_EQ(arr[1], 5);
+        ASSERT_EQ(arr[2], 6);
+        ASSERT_EQ(arr[3], 7);
+        ASSERT_EQ(arr[4], 8);
+    }
+}
+
+
+TEST(Common, PODArrayBasicSwap)
+{
+    using namespace DB;
+
+    static constexpr size_t initial_bytes = 32;
+    using Array = PODArray<UInt64, initial_bytes,
+        AllocatorWithStackMemory<Allocator<false>, initial_bytes>>;
+
+    {
+        Array arr;
+        Array arr2;
+        arr.swap(arr2);
+        arr2.swap(arr);
+    }
+
+    {
+        Array arr;
+
+        Array arr2;
+
+        arr2.push_back(1);
+        arr2.push_back(2);
+        arr2.push_back(3);
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.size() == 3);
+        ASSERT_TRUE(arr[0] == 1);
+        ASSERT_TRUE(arr[1] == 2);
+        ASSERT_TRUE(arr[2] == 3);
+
+        ASSERT_TRUE(arr2.empty());
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.empty());
+
+        ASSERT_TRUE(arr2.size() == 3);
+        ASSERT_TRUE(arr2[0] == 1);
+        ASSERT_TRUE(arr2[1] == 2);
+        ASSERT_TRUE(arr2[2] == 3);
+    }
+
+    {
+        Array arr;
+
+        Array arr2;
+
+        arr2.push_back(1);
+        arr2.push_back(2);
+        arr2.push_back(3);
+        arr2.push_back(4);
+        arr2.push_back(5);
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.size() == 5);
+        ASSERT_TRUE(arr[0] == 1);
+        ASSERT_TRUE(arr[1] == 2);
+        ASSERT_TRUE(arr[2] == 3);
+        ASSERT_TRUE(arr[3] == 4);
+        ASSERT_TRUE(arr[4] == 5);
+
+        ASSERT_TRUE(arr2.empty());
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.empty());
+
+        ASSERT_TRUE(arr2.size() == 5);
+        ASSERT_TRUE(arr2[0] == 1);
+        ASSERT_TRUE(arr2[1] == 2);
+        ASSERT_TRUE(arr2[2] == 3);
+        ASSERT_TRUE(arr2[3] == 4);
+        ASSERT_TRUE(arr2[4] == 5);
+    }
+
+    {
+        Array arr;
+
+        arr.push_back(1);
+        arr.push_back(2);
+        arr.push_back(3);
+
+        Array arr2;
+
+        arr2.push_back(4);
+        arr2.push_back(5);
+        arr2.push_back(6);
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.size() == 3);
+        ASSERT_TRUE(arr[0] == 4);
+        ASSERT_TRUE(arr[1] == 5);
+        ASSERT_TRUE(arr[2] == 6);
+
+        ASSERT_TRUE(arr2.size() == 3);
+        ASSERT_TRUE(arr2[0] == 1);
+        ASSERT_TRUE(arr2[1] == 2);
+        ASSERT_TRUE(arr2[2] == 3);
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.size() == 3);
+        ASSERT_TRUE(arr[0] == 1);
+        ASSERT_TRUE(arr[1] == 2);
+        ASSERT_TRUE(arr[2] == 3);
+
+        ASSERT_TRUE(arr2.size() == 3);
+        ASSERT_TRUE(arr2[0] == 4);
+        ASSERT_TRUE(arr2[1] == 5);
+        ASSERT_TRUE(arr2[2] == 6);
+    }
+
+    {
+        Array arr;
+
+        arr.push_back(1);
+        arr.push_back(2);
+
+        Array arr2;
+
+        arr2.push_back(3);
+        arr2.push_back(4);
+        arr2.push_back(5);
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.size() == 3);
+        ASSERT_TRUE(arr[0] == 3);
+        ASSERT_TRUE(arr[1] == 4);
+        ASSERT_TRUE(arr[2] == 5);
+
+        ASSERT_TRUE(arr2.size() == 2);
+        ASSERT_TRUE(arr2[0] == 1);
+        ASSERT_TRUE(arr2[1] == 2);
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.size() == 2);
+        ASSERT_TRUE(arr[0] == 1);
+        ASSERT_TRUE(arr[1] == 2);
+
+        ASSERT_TRUE(arr2.size() == 3);
+        ASSERT_TRUE(arr2[0] == 3);
+        ASSERT_TRUE(arr2[1] == 4);
+        ASSERT_TRUE(arr2[2] == 5);
+    }
+
+    {
+        Array arr;
+
+        arr.push_back(1);
+        arr.push_back(2);
+        arr.push_back(3);
+
+        Array arr2;
+
+        arr2.push_back(4);
+        arr2.push_back(5);
+        arr2.push_back(6);
+        arr2.push_back(7);
+        arr2.push_back(8);
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.size() == 5);
+        ASSERT_TRUE(arr[0] == 4);
+        ASSERT_TRUE(arr[1] == 5);
+        ASSERT_TRUE(arr[2] == 6);
+        ASSERT_TRUE(arr[3] == 7);
+        ASSERT_TRUE(arr[4] == 8);
+
+        ASSERT_TRUE(arr2.size() == 3);
+        ASSERT_TRUE(arr2[0] == 1);
+        ASSERT_TRUE(arr2[1] == 2);
+        ASSERT_TRUE(arr2[2] == 3);
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.size() == 3);
+        ASSERT_TRUE(arr[0] == 1);
+        ASSERT_TRUE(arr[1] == 2);
+        ASSERT_TRUE(arr[2] == 3);
+
+        ASSERT_TRUE(arr2.size() == 5);
+        ASSERT_TRUE(arr2[0] == 4);
+        ASSERT_TRUE(arr2[1] == 5);
+        ASSERT_TRUE(arr2[2] == 6);
+        ASSERT_TRUE(arr2[3] == 7);
+        ASSERT_TRUE(arr2[4] == 8);
+    }
+
+    {
+        Array arr;
+
+        arr.push_back(1);
+        arr.push_back(2);
+        arr.push_back(3);
+        arr.push_back(4);
+        arr.push_back(5);
+
+        Array arr2;
+
+        arr2.push_back(6);
+        arr2.push_back(7);
+        arr2.push_back(8);
+        arr2.push_back(9);
+        arr2.push_back(10);
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.size() == 5);
+        ASSERT_TRUE(arr[0] == 6);
+        ASSERT_TRUE(arr[1] == 7);
+        ASSERT_TRUE(arr[2] == 8);
+        ASSERT_TRUE(arr[3] == 9);
+        ASSERT_TRUE(arr[4] == 10);
+
+        ASSERT_TRUE(arr2.size() == 5);
+        ASSERT_TRUE(arr2[0] == 1);
+        ASSERT_TRUE(arr2[1] == 2);
+        ASSERT_TRUE(arr2[2] == 3);
+        ASSERT_TRUE(arr2[3] == 4);
+        ASSERT_TRUE(arr2[4] == 5);
+
+        arr.swap(arr2);
+
+        ASSERT_TRUE(arr.size() == 5);
+        ASSERT_TRUE(arr[0] == 1);
+        ASSERT_TRUE(arr[1] == 2);
+        ASSERT_TRUE(arr[2] == 3);
+        ASSERT_TRUE(arr[3] == 4);
+        ASSERT_TRUE(arr[4] == 5);
+
+        ASSERT_TRUE(arr2.size() == 5);
+        ASSERT_TRUE(arr2[0] == 6);
+        ASSERT_TRUE(arr2[1] == 7);
+        ASSERT_TRUE(arr2[2] == 8);
+        ASSERT_TRUE(arr2[3] == 9);
+        ASSERT_TRUE(arr2[4] == 10);
+    }
+}
+
+TEST(Common, PODArrayBasicSwapMoveConstructor)
+{
+    static constexpr size_t initial_bytes = 32;
+    using Array = PODArray<UInt64, initial_bytes,
+        AllocatorWithStackMemory<Allocator<false>, initial_bytes>>;
+
+    {
+        Array arr;
+        Array arr2{std::move(arr)};
+    }
+
+    {
+        Array arr;
+
+        arr.push_back(1);
+        arr.push_back(2);
+        arr.push_back(3);
+
+        Array arr2{std::move(arr)};
+
+        ASSERT_TRUE(arr.empty()); // NOLINT
+
+        ASSERT_TRUE(arr2.size() == 3);
+        ASSERT_TRUE(arr2[0] == 1);
+        ASSERT_TRUE(arr2[1] == 2);
+        ASSERT_TRUE(arr2[2] == 3);
+    }
+
+    {
+        Array arr;
+
+        arr.push_back(1);
+        arr.push_back(2);
+        arr.push_back(3);
+        arr.push_back(4);
+        arr.push_back(5);
+
+        Array arr2{std::move(arr)};
+
+        ASSERT_TRUE(arr.empty()); // NOLINT
+
+        ASSERT_TRUE(arr2.size() == 5);
+        ASSERT_TRUE(arr2[0] == 1);
+        ASSERT_TRUE(arr2[1] == 2);
+        ASSERT_TRUE(arr2[2] == 3);
+        ASSERT_TRUE(arr2[3] == 4);
+        ASSERT_TRUE(arr2[4] == 5);
+    }
+}
+
 TEST(Common, PODArrayInsert)
 {
    std::string str = "test_string_abacaba";
--- a/src/Common/tests/pod_array.cpp
+++ b/src/Common/tests/pod_array.cpp
@ -1,455 +0,0 @@
-#include <Common/PODArray.h>
-#include <common/types.h>
-#include <iostream>
-
-#define ASSERT_CHECK(cond, res)                        \
-do                                    \
-{                                    \
-    if (!(cond))                            \
-    {                                \
-        std::cerr << __FILE__ << ":" << __LINE__ << ":"        \
-            << "Assertion " << #cond << " failed.\n";    \
-        if ((res)) { (res) = false; }                \
-    }                                \
-} \
-while (false)
-
-static void test1()
-{
-    using namespace DB;
-
-    static constexpr size_t initial_bytes = 32;
-    using Array = PODArray<UInt64, initial_bytes,
-        AllocatorWithStackMemory<Allocator<false>, initial_bytes>>;
-
-    bool res = true;
-
-    {
-        Array arr;
-        Array arr2;
-        arr2 = std::move(arr);
-    }
-
-    {
-        Array arr;
-
-        arr.push_back(1);
-        arr.push_back(2);
-        arr.push_back(3);
-
-        Array arr2;
-
-        arr2 = std::move(arr);
-
-        ASSERT_CHECK((arr2.size() == 3), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-        ASSERT_CHECK((arr2[2] == 3), res);
-
-        arr = std::move(arr2);
-
-        ASSERT_CHECK((arr.size() == 3), res);
-        ASSERT_CHECK((arr[0] == 1), res);
-        ASSERT_CHECK((arr[1] == 2), res);
-        ASSERT_CHECK((arr[2] == 3), res);
-    }
-
-    {
-        Array arr;
-
-        arr.push_back(1);
-        arr.push_back(2);
-        arr.push_back(3);
-        arr.push_back(4);
-        arr.push_back(5);
-
-        Array arr2;
-
-        arr2 = std::move(arr);
-
-        ASSERT_CHECK((arr2.size() == 5), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-        ASSERT_CHECK((arr2[2] == 3), res);
-        ASSERT_CHECK((arr2[3] == 4), res);
-        ASSERT_CHECK((arr2[4] == 5), res);
-
-        arr = std::move(arr2);
-
-        ASSERT_CHECK((arr.size() == 5), res);
-        ASSERT_CHECK((arr[0] == 1), res);
-        ASSERT_CHECK((arr[1] == 2), res);
-        ASSERT_CHECK((arr[2] == 3), res);
-        ASSERT_CHECK((arr[3] == 4), res);
-        ASSERT_CHECK((arr[4] == 5), res);
-    }
-
-    {
-        Array arr;
-
-        arr.push_back(1);
-        arr.push_back(2);
-        arr.push_back(3);
-
-        Array arr2;
-
-        arr2.push_back(4);
-        arr2.push_back(5);
-        arr2.push_back(6);
-        arr2.push_back(7);
-
-        arr2 = std::move(arr);
-
-        ASSERT_CHECK((arr2.size() == 3), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-        ASSERT_CHECK((arr2[2] == 3), res);
-    }
-
-    {
-        Array arr;
-
-        arr.push_back(1);
-        arr.push_back(2);
-        arr.push_back(3);
-
-        Array arr2;
-
-        arr2.push_back(4);
-        arr2.push_back(5);
-        arr2.push_back(6);
-        arr2.push_back(7);
-        arr2.push_back(8);
-
-        arr = std::move(arr2);
-
-        ASSERT_CHECK((arr.size() == 5), res);
-        ASSERT_CHECK((arr[0] == 4), res);
-        ASSERT_CHECK((arr[1] == 5), res);
-        ASSERT_CHECK((arr[2] == 6), res);
-        ASSERT_CHECK((arr[3] == 7), res);
-        ASSERT_CHECK((arr[4] == 8), res);
-    }
-
-    if (!res)
-        std::cerr << "Some errors were found in test 1\n";
-}
-
-static void test2()
-{
-    using namespace DB;
-
-    static constexpr size_t initial_bytes = 32;
-    using Array = PODArray<UInt64, initial_bytes,
-        AllocatorWithStackMemory<Allocator<false>, initial_bytes>>;
-
-    bool res = true;
-
-    {
-        Array arr;
-        Array arr2;
-        arr.swap(arr2);
-        arr2.swap(arr);
-    }
-
-    {
-        Array arr;
-
-        Array arr2;
-
-        arr2.push_back(1);
-        arr2.push_back(2);
-        arr2.push_back(3);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.size() == 3), res);
-        ASSERT_CHECK((arr[0] == 1), res);
-        ASSERT_CHECK((arr[1] == 2), res);
-        ASSERT_CHECK((arr[2] == 3), res);
-
-        ASSERT_CHECK((arr2.empty()), res);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.empty()), res);
-
-        ASSERT_CHECK((arr2.size() == 3), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-        ASSERT_CHECK((arr2[2] == 3), res);
-    }
-
-    {
-        Array arr;
-
-        Array arr2;
-
-        arr2.push_back(1);
-        arr2.push_back(2);
-        arr2.push_back(3);
-        arr2.push_back(4);
-        arr2.push_back(5);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.size() == 5), res);
-        ASSERT_CHECK((arr[0] == 1), res);
-        ASSERT_CHECK((arr[1] == 2), res);
-        ASSERT_CHECK((arr[2] == 3), res);
-        ASSERT_CHECK((arr[3] == 4), res);
-        ASSERT_CHECK((arr[4] == 5), res);
-
-        ASSERT_CHECK((arr2.empty()), res);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.empty()), res);
-
-        ASSERT_CHECK((arr2.size() == 5), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-        ASSERT_CHECK((arr2[2] == 3), res);
-        ASSERT_CHECK((arr2[3] == 4), res);
-        ASSERT_CHECK((arr2[4] == 5), res);
-    }
-
-    {
-        Array arr;
-
-        arr.push_back(1);
-        arr.push_back(2);
-        arr.push_back(3);
-
-        Array arr2;
-
-        arr2.push_back(4);
-        arr2.push_back(5);
-        arr2.push_back(6);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.size() == 3), res);
-        ASSERT_CHECK((arr[0] == 4), res);
-        ASSERT_CHECK((arr[1] == 5), res);
-        ASSERT_CHECK((arr[2] == 6), res);
-
-        ASSERT_CHECK((arr2.size() == 3), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-        ASSERT_CHECK((arr2[2] == 3), res);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.size() == 3), res);
-        ASSERT_CHECK((arr[0] == 1), res);
-        ASSERT_CHECK((arr[1] == 2), res);
-        ASSERT_CHECK((arr[2] == 3), res);
-
-        ASSERT_CHECK((arr2.size() == 3), res);
-        ASSERT_CHECK((arr2[0] == 4), res);
-        ASSERT_CHECK((arr2[1] == 5), res);
-        ASSERT_CHECK((arr2[2] == 6), res);
-    }
-
-    {
-        Array arr;
-
-        arr.push_back(1);
-        arr.push_back(2);
-
-        Array arr2;
-
-        arr2.push_back(3);
-        arr2.push_back(4);
-        arr2.push_back(5);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.size() == 3), res);
-        ASSERT_CHECK((arr[0] == 3), res);
-        ASSERT_CHECK((arr[1] == 4), res);
-        ASSERT_CHECK((arr[2] == 5), res);
-
-        ASSERT_CHECK((arr2.size() == 2), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.size() == 2), res);
-        ASSERT_CHECK((arr[0] == 1), res);
-        ASSERT_CHECK((arr[1] == 2), res);
-
-        ASSERT_CHECK((arr2.size() == 3), res);
-        ASSERT_CHECK((arr2[0] == 3), res);
-        ASSERT_CHECK((arr2[1] == 4), res);
-        ASSERT_CHECK((arr2[2] == 5), res);
-    }
-
-    {
-        Array arr;
-
-        arr.push_back(1);
-        arr.push_back(2);
-        arr.push_back(3);
-
-        Array arr2;
-
-        arr2.push_back(4);
-        arr2.push_back(5);
-        arr2.push_back(6);
-        arr2.push_back(7);
-        arr2.push_back(8);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.size() == 5), res);
-        ASSERT_CHECK((arr[0] == 4), res);
-        ASSERT_CHECK((arr[1] == 5), res);
-        ASSERT_CHECK((arr[2] == 6), res);
-        ASSERT_CHECK((arr[3] == 7), res);
-        ASSERT_CHECK((arr[4] == 8), res);
-
-        ASSERT_CHECK((arr2.size() == 3), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-        ASSERT_CHECK((arr2[2] == 3), res);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.size() == 3), res);
-        ASSERT_CHECK((arr[0] == 1), res);
-        ASSERT_CHECK((arr[1] == 2), res);
-        ASSERT_CHECK((arr[2] == 3), res);
-
-        ASSERT_CHECK((arr2.size() == 5), res);
-        ASSERT_CHECK((arr2[0] == 4), res);
-        ASSERT_CHECK((arr2[1] == 5), res);
-        ASSERT_CHECK((arr2[2] == 6), res);
-        ASSERT_CHECK((arr2[3] == 7), res);
-        ASSERT_CHECK((arr2[4] == 8), res);
-    }
-
-    {
-        Array arr;
-
-        arr.push_back(1);
-        arr.push_back(2);
-        arr.push_back(3);
-        arr.push_back(4);
-        arr.push_back(5);
-
-        Array arr2;
-
-        arr2.push_back(6);
-        arr2.push_back(7);
-        arr2.push_back(8);
-        arr2.push_back(9);
-        arr2.push_back(10);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.size() == 5), res);
-        ASSERT_CHECK((arr[0] == 6), res);
-        ASSERT_CHECK((arr[1] == 7), res);
-        ASSERT_CHECK((arr[2] == 8), res);
-        ASSERT_CHECK((arr[3] == 9), res);
-        ASSERT_CHECK((arr[4] == 10), res);
-
-        ASSERT_CHECK((arr2.size() == 5), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-        ASSERT_CHECK((arr2[2] == 3), res);
-        ASSERT_CHECK((arr2[3] == 4), res);
-        ASSERT_CHECK((arr2[4] == 5), res);
-
-        arr.swap(arr2);
-
-        ASSERT_CHECK((arr.size() == 5), res);
-        ASSERT_CHECK((arr[0] == 1), res);
-        ASSERT_CHECK((arr[1] == 2), res);
-        ASSERT_CHECK((arr[2] == 3), res);
-        ASSERT_CHECK((arr[3] == 4), res);
-        ASSERT_CHECK((arr[4] == 5), res);
-
-        ASSERT_CHECK((arr2.size() == 5), res);
-        ASSERT_CHECK((arr2[0] == 6), res);
-        ASSERT_CHECK((arr2[1] == 7), res);
-        ASSERT_CHECK((arr2[2] == 8), res);
-        ASSERT_CHECK((arr2[3] == 9), res);
-        ASSERT_CHECK((arr2[4] == 10), res);
-    }
-
-    if (!res)
-        std::cerr << "Some errors were found in test 2\n";
-}
-
-static void test3()
-{
-    using namespace DB;
-
-    static constexpr size_t initial_bytes = 32;
-    using Array = PODArray<UInt64, initial_bytes,
-        AllocatorWithStackMemory<Allocator<false>, initial_bytes>>;
-
-    bool res = true;
-
-    {
-        Array arr;
-        Array arr2{std::move(arr)};
-    }
-
-    {
-        Array arr;
-
-        arr.push_back(1);
-        arr.push_back(2);
-        arr.push_back(3);
-
-        Array arr2{std::move(arr)};
-
-        ASSERT_CHECK((arr.empty()), res); // NOLINT
-
-        ASSERT_CHECK((arr2.size() == 3), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-        ASSERT_CHECK((arr2[2] == 3), res);
-    }
-
-    {
-        Array arr;
-
-        arr.push_back(1);
-        arr.push_back(2);
-        arr.push_back(3);
-        arr.push_back(4);
-        arr.push_back(5);
-
-        Array arr2{std::move(arr)};
-
-        ASSERT_CHECK((arr.empty()), res); // NOLINT
-
-        ASSERT_CHECK((arr2.size() == 5), res);
-        ASSERT_CHECK((arr2[0] == 1), res);
-        ASSERT_CHECK((arr2[1] == 2), res);
-        ASSERT_CHECK((arr2[2] == 3), res);
-        ASSERT_CHECK((arr2[3] == 4), res);
-        ASSERT_CHECK((arr2[4] == 5), res);
-    }
-
-    if (!res)
-        std::cerr << "Some errors were found in test 3\n";
-}
-
-int main()
-{
-    std::cout << "test 1\n";
-    test1();
-    std::cout << "test 2\n";
-    test2();
-    std::cout << "test 3\n";
-    test3();
-
-    return 0;
-}
--- a/src/Common/ya.make
+++ b/src/Common/ya.make
@ -47,6 +47,7 @@ SRCS(
    FileChecker.cpp
    IPv6ToBinary.cpp
    IntervalKind.cpp
+    JSONBuilder.cpp
    Macros.cpp
    MemoryStatisticsOS.cpp
    MemoryTracker.cpp
--- a/src/Compression/CMakeLists.txt
+++ b/src/Compression/CMakeLists.txt
@ -1,3 +1,3 @@
-if(ENABLE_TESTS)
-    add_subdirectory(tests)
+if(ENABLE_EXAMPLES)
+    add_subdirectory(examples)
 endif()
--- a/src/Compression/examples/CMakeLists.txt
+++ b/src/Compression/examples/CMakeLists.txt
--- a/src/Compression/examples/cached_compressed_read_buffer.cpp
+++ b/src/Compression/examples/cached_compressed_read_buffer.cpp
--- a/src/Compression/examples/compressed_buffer.cpp
+++ b/src/Compression/examples/compressed_buffer.cpp
--- a/src/Compression/examples/compressed_buffer_fuzzer.cpp
+++ b/src/Compression/examples/compressed_buffer_fuzzer.cpp
--- a/src/Core/CMakeLists.txt
+++ b/src/Core/CMakeLists.txt
@ -1,3 +1,3 @@
-if (ENABLE_TESTS)
-    add_subdirectory (tests)
+if (ENABLE_EXAMPLES)
+    add_subdirectory(examples)
 endif ()
--- a/src/Core/Settings.h
+++ b/src/Core/Settings.h
@ -435,7 +435,7 @@ class IColumn;
    M(Bool, allow_experimental_map_type, false, "Allow data type Map", 0) \
    M(Bool, allow_experimental_window_functions, false, "Allow experimental window functions", 0) \
    M(Bool, use_antlr_parser, false, "Parse incoming queries using ANTLR-generated experimental parser", 0) \
-    M(Bool, async_socket_for_remote, false, "Asynchronously read from socket executing remote query", 0) \
+    M(Bool, async_socket_for_remote, true, "Asynchronously read from socket executing remote query", 0) \
    M(Bool, insert_null_as_default, true, "Insert DEFAULT values instead of NULL in INSERT SELECT (UNION ALL)", 0) \
    \
    M(Bool, optimize_rewrite_sum_if_to_count_if, true, "Rewrite sumIf() and sum(if()) function countIf() function when logically equivalent", 0) \
--- a/src/Core/SortDescription.cpp
+++ b/src/Core/SortDescription.cpp
@ -1,6 +1,7 @@
 #include <Core/SortDescription.h>
 #include <Core/Block.h>
 #include <IO/Operators.h>
+#include <Common/JSONBuilder.h>

 namespace DB
 {
@ -37,6 +38,22 @@ void dumpSortDescription(const SortDescription & description, const Block & head
    }
 }

+void SortColumnDescription::explain(JSONBuilder::JSONMap & map, const Block & header) const
+{
+    if (!column_name.empty())
+        map.add("Column", column_name);
+    else
+    {
+        if (column_number < header.columns())
+            map.add("Column", header.getByPosition(column_number).name);
+
+        map.add("Position", column_number);
+    }
+
+    map.add("Ascending", direction > 0);
+    map.add("With Fill", with_fill);
+}
+
 std::string dumpSortDescription(const SortDescription & description)
 {
    WriteBufferFromOwnString wb;
@ -44,5 +61,17 @@ std::string dumpSortDescription(const SortDescription & description)
    return wb.str();
 }

+JSONBuilder::ItemPtr explainSortDescription(const SortDescription & description, const Block & header)
+{
+    auto json_array = std::make_unique<JSONBuilder::JSONArray>();
+    for (const auto & descr : description)
+    {
+        auto json_map = std::make_unique<JSONBuilder::JSONMap>();
+        descr.explain(*json_map, header);
+        json_array->add(std::move(json_map));
+    }
+
+    return json_array;
 }

+}
--- a/src/Core/SortDescription.h
+++ b/src/Core/SortDescription.h
@ -12,6 +12,15 @@ class Collator;
 namespace DB
 {

+namespace JSONBuilder
+{
+    class JSONMap;
+    class IItem;
+    using ItemPtr = std::unique_ptr<IItem>;
+}
+
+class Block;
+
 struct FillColumnDescription
 {
    /// All missed values in range [FROM, TO) will be filled
@ -62,16 +71,18 @@ struct SortColumnDescription
    {
        return fmt::format("{}:{}:dir {}nulls ", column_name, column_number, direction, nulls_direction);
    }
+
+    void explain(JSONBuilder::JSONMap & map, const Block & header) const;
 };

 /// Description of the sorting rule for several columns.
 using SortDescription = std::vector<SortColumnDescription>;

-class Block;
-
 /// Outputs user-readable description into `out`.
 void dumpSortDescription(const SortDescription & description, const Block & header, WriteBuffer & out);

 std::string dumpSortDescription(const SortDescription & description);

+JSONBuilder::ItemPtr explainSortDescription(const SortDescription & description, const Block & header);
+
 }
--- a/src/Core/examples/CMakeLists.txt
+++ b/src/Core/examples/CMakeLists.txt
--- a/src/Core/examples/field.cpp
+++ b/src/Core/examples/field.cpp
--- a/src/Core/examples/mysql_protocol.cpp
+++ b/src/Core/examples/mysql_protocol.cpp
--- a/src/Core/examples/names_and_types_fuzzer.cpp
+++ b/src/Core/examples/names_and_types_fuzzer.cpp
--- a/src/Core/examples/string_pool.cpp
+++ b/src/Core/examples/string_pool.cpp
--- a/src/Core/examples/string_ref_hash.cpp
+++ b/src/Core/examples/string_ref_hash.cpp
--- a/src/DataStreams/CMakeLists.txt
+++ b/src/DataStreams/CMakeLists.txt
@ -1,3 +1,3 @@
-if (ENABLE_TESTS)
-    add_subdirectory (tests)
+if (ENABLE_EXAMPLES)
+    add_subdirectory(examples)
 endif ()
--- a/src/DataStreams/examples/CMakeLists.txt
+++ b/src/DataStreams/examples/CMakeLists.txt
--- a/src/DataTypes/CMakeLists.txt
+++ b/src/DataTypes/CMakeLists.txt
@ -1,3 +1,3 @@
-if (ENABLE_TESTS)
-    add_subdirectory (tests)
+if (ENABLE_EXAMPLES)
+    add_subdirectory(examples)
 endif ()
--- a/src/DataTypes/Serializations/SerializationNumber.cpp
+++ b/src/DataTypes/Serializations/SerializationNumber.cpp
@ -33,55 +33,11 @@ void SerializationNumber<T>::deserializeText(IColumn & column, ReadBuffer & istr
    assert_cast<ColumnVector<T> &>(column).getData().push_back(x);
 }

-template <typename T>
-static inline void writeDenormalNumber(T x, WriteBuffer & ostr)
-{
-    if constexpr (std::is_floating_point_v<T>)
-    {
-        if (std::signbit(x))
-        {
-            if (isNaN(x))
-                writeCString("-nan", ostr);
-            else
-                writeCString("-inf", ostr);
-        }
-        else
-        {
-            if (isNaN(x))
-                writeCString("nan", ostr);
-            else
-                writeCString("inf", ostr);
-        }
-    }
-    else
-    {
-        /// This function is not called for non floating point numbers.
-        (void)x;
-    }
-}
-
-
 template <typename T>
 void SerializationNumber<T>::serializeTextJSON(const IColumn & column, size_t row_num, WriteBuffer & ostr, const FormatSettings & settings) const
 {
    auto x = assert_cast<const ColumnVector<T> &>(column).getData()[row_num];
-    bool is_finite = isFinite(x);
-
-    const bool need_quote = (is_integer_v<T> && (sizeof(T) >= 8) && settings.json.quote_64bit_integers)
-        || (settings.json.quote_denormals && !is_finite);
-
-    if (need_quote)
-        writeChar('"', ostr);
-
-    if (is_finite)
-        writeText(x, ostr);
-    else if (!settings.json.quote_denormals)
-        writeCString("null", ostr);
-    else
-        writeDenormalNumber(x, ostr);
-
-    if (need_quote)
-        writeChar('"', ostr);
+    writeJSONNumber(x, ostr, settings);
 }

 template <typename T>
--- a/src/DataTypes/examples/CMakeLists.txt
+++ b/src/DataTypes/examples/CMakeLists.txt
--- a/src/Databases/DatabaseAtomic.cpp
+++ b/src/Databases/DatabaseAtomic.cpp
@ -91,7 +91,7 @@ void DatabaseAtomic::attachTable(const String & name, const StoragePtr & table,
    not_in_use = cleanupDetachedTables();
    auto table_id = table->getStorageID();
    assertDetachedTableNotInUse(table_id.uuid);
-    DatabaseWithDictionaries::attachTableUnlocked(name, table, lock);
+    DatabaseOrdinary::attachTableUnlocked(name, table, lock);
    table_name_to_path.emplace(std::make_pair(name, relative_table_path));
 }

@ -99,7 +99,7 @@ StoragePtr DatabaseAtomic::detachTable(const String & name)
 {
    DetachedTables not_in_use;
    std::unique_lock lock(mutex);
-    auto table = DatabaseWithDictionaries::detachTableUnlocked(name, lock);
+    auto table = DatabaseOrdinary::detachTableUnlocked(name, lock);
    table_name_to_path.erase(name);
    detached_tables.emplace(table->getStorageID().uuid, table);
    not_in_use = cleanupDetachedTables();
@ -133,9 +133,10 @@ void DatabaseAtomic::dropTable(ContextPtr local_context, const String & table_na
        /// TODO better detection and recovery

        Poco::File(table_metadata_path).renameTo(table_metadata_path_drop);    /// Mark table as dropped
-        DatabaseWithDictionaries::detachTableUnlocked(table_name, lock);       /// Should never throw
+        DatabaseOrdinary::detachTableUnlocked(table_name, lock);       /// Should never throw
        table_name_to_path.erase(table_name);
    }
+
    if (table->storesDataOnDisk())
        tryRemoveSymlink(table_name);

@ -156,8 +157,6 @@ void DatabaseAtomic::renameTable(ContextPtr local_context, const String & table_
        return;
    }

-    if (exchange && dictionary)
-        throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Cannot exchange dictionaries");
    if (exchange && !supportsRenameat2())
        throw Exception(ErrorCodes::NOT_IMPLEMENTED, "RENAME EXCHANGE is not supported");

@ -174,7 +173,7 @@ void DatabaseAtomic::renameTable(ContextPtr local_context, const String & table_
        /// Path can be not set for DDL dictionaries, but it does not matter for StorageDictionary.
        if (it != db.table_name_to_path.end())
            table_data_path_saved = it->second;
-        assert(!table_data_path_saved.empty() || db.dictionaries.find(table_name_) != db.dictionaries.end());
+        assert(!table_data_path_saved.empty());
        db.tables.erase(table_name_);
        db.table_name_to_path.erase(table_name_);
        if (has_symlink)
@ -222,21 +221,21 @@ void DatabaseAtomic::renameTable(ContextPtr local_context, const String & table_
        db_lock = std::unique_lock{mutex};
    }

-    bool is_dictionary = dictionaries.find(table_name) != dictionaries.end();
-    if (exchange && other_db.dictionaries.find(to_table_name) != other_db.dictionaries.end())
-        throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Cannot exchange dictionaries");
-
-    if (dictionary != is_dictionary)
-        throw Exception(ErrorCodes::INCORRECT_QUERY,
-                        "Use RENAME DICTIONARY for dictionaries and RENAME TABLE for tables.");
-
-    if (is_dictionary && !inside_database)
-        throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Cannot move dictionary to other database");
-
    if (!exchange)
        other_db.checkMetadataFilenameAvailabilityUnlocked(to_table_name, inside_database ? db_lock : other_db_lock);

    StoragePtr table = getTableUnlocked(table_name, db_lock);
+
+    if (table->isDictionary() && !dictionary)
+    {
+        if (exchange)
+            throw Exception(ErrorCodes::INCORRECT_QUERY,
+                "Use EXCHANGE DICTIONARIES for dictionaries and EXCHANGE TABLES for tables.");
+        else
+            throw Exception(ErrorCodes::INCORRECT_QUERY,
+                "Use RENAME DICTIONARY for dictionaries and RENAME TABLE for tables.");
+    }
+
    table->checkTableCanBeRenamed();
    assert_can_move_mat_view(table);
    StoragePtr other_table;
@ -281,12 +280,6 @@ void DatabaseAtomic::renameTable(ContextPtr local_context, const String & table_
    attach(other_db, to_table_name, table_data_path, table);
    if (exchange)
        attach(*this, table_name, other_table_data_path, other_table);
-
-    if (is_dictionary)
-    {
-        auto new_table_id = StorageID(other_db.database_name, to_table_name, old_table_id.uuid);
-        renameDictionaryInMemoryUnlocked(old_table_id, new_table_id);
-    }
 }

 void DatabaseAtomic::commitCreateTable(const ASTCreateQuery & query, const StoragePtr & table,
@ -528,14 +521,6 @@ void DatabaseAtomic::renameDatabase(const String & new_name)
            table.second->renameInMemory(table_id);
        }

-        for (auto & dict : dictionaries)
-        {
-            auto old_name = StorageID(dict.second.create_query);
-            auto name = old_name;
-            name.database_name = database_name;
-            renameDictionaryInMemoryUnlocked(old_name, name);
-        }
-
        path_to_metadata_symlink = getContext()->getPath() + "metadata/" + new_name_escaped;
        old_path_to_table_symlinks = path_to_table_symlinks;
        path_to_table_symlinks = getContext()->getPath() + "data/" + new_name_escaped + "/";
@ -545,32 +530,6 @@ void DatabaseAtomic::renameDatabase(const String & new_name)
    tryCreateMetadataSymlink();
 }

-void DatabaseAtomic::renameDictionaryInMemoryUnlocked(const StorageID & old_name, const StorageID & new_name)
-{
-    auto it = dictionaries.find(old_name.table_name);
-    assert(it != dictionaries.end());
-    assert(it->second.config->getString("dictionary.uuid") == toString(old_name.uuid));
-    assert(old_name.uuid == new_name.uuid);
-    it->second.config->setString("dictionary.database", new_name.database_name);
-    it->second.config->setString("dictionary.name", new_name.table_name);
-    auto & create = it->second.create_query->as<ASTCreateQuery &>();
-    create.database = new_name.database_name;
-    create.table = new_name.table_name;
-    assert(create.uuid == new_name.uuid);
-
-    if (old_name.table_name != new_name.table_name)
-    {
-        auto attach_info = std::move(it->second);
-        dictionaries.erase(it);
-        dictionaries.emplace(new_name.table_name, std::move(attach_info));
-    }
-
-    auto result = external_loader.getLoadResult(toString(old_name.uuid));
-    if (!result.object)
-        return;
-    const auto & dict = dynamic_cast<const IDictionary &>(*result.object);
-    dict.updateDictionaryName(new_name);
-}
 void DatabaseAtomic::waitDetachedTableNotInUse(const UUID & uuid)
 {
    /// Table is in use while its shared_ptr counter is greater than 1.
--- a/src/Databases/DatabaseAtomic.h
+++ b/src/Databases/DatabaseAtomic.h
@ -72,8 +72,6 @@ protected:

    void tryCreateMetadataSymlink();

-    void renameDictionaryInMemoryUnlocked(const StorageID & old_name, const StorageID & new_name);
-
    //TODO store path in DatabaseWithOwnTables::tables
    using NameToPathMap = std::unordered_map<String, String>;
    NameToPathMap table_name_to_path;
--- a/src/Databases/DatabaseDictionary.cpp
+++ b/src/Databases/DatabaseDictionary.cpp
@ -21,18 +21,20 @@ namespace ErrorCodes

 namespace
 {
-    StoragePtr createStorageDictionary(const String & database_name, const ExternalLoader::LoadResult & load_result)
+    StoragePtr createStorageDictionary(const String & database_name, const ExternalLoader::LoadResult & load_result, ContextPtr context)
    {
        try
        {
            if (!load_result.config)
                return nullptr;
+
            DictionaryStructure dictionary_structure = ExternalDictionariesLoader::getDictionaryStructure(*load_result.config);
            return StorageDictionary::create(
                StorageID(database_name, load_result.name),
                load_result.name,
                dictionary_structure,
-                StorageDictionary::Location::DictionaryDatabase);
+                StorageDictionary::Location::DictionaryDatabase,
+                context);
        }
        catch (Exception & e)
        {
@ -57,7 +59,7 @@ Tables DatabaseDictionary::listTables(const FilterByNameFunction & filter_by_nam
    String db_name = getDatabaseName();
    for (auto & load_result : load_results)
    {
-        auto storage = createStorageDictionary(db_name, load_result);
+        auto storage = createStorageDictionary(db_name, load_result, getContext());
        if (storage)
            tables.emplace(storage->getStorageID().table_name, storage);
    }
@ -72,7 +74,7 @@ bool DatabaseDictionary::isTableExist(const String & table_name, ContextPtr) con
 StoragePtr DatabaseDictionary::tryGetTable(const String & table_name, ContextPtr) const
 {
    auto load_result = getContext()->getExternalDictionariesLoader().getLoadResult(table_name);
-    return createStorageDictionary(getDatabaseName(), load_result);
+    return createStorageDictionary(getDatabaseName(), load_result, getContext());
 }

 DatabaseTablesIteratorPtr DatabaseDictionary::getTablesIterator(ContextPtr, const FilterByNameFunction & filter_by_table_name)
--- a/src/Databases/DatabaseOnDisk.cpp
+++ b/src/Databases/DatabaseOnDisk.cpp
@ -37,7 +37,6 @@ namespace ErrorCodes
    extern const int INCORRECT_FILE_NAME;
    extern const int SYNTAX_ERROR;
    extern const int TABLE_ALREADY_EXISTS;
-    extern const int DICTIONARY_ALREADY_EXISTS;
    extern const int EMPTY_LIST_OF_COLUMNS_PASSED;
 }

@ -63,14 +62,21 @@ std::pair<String, StoragePtr> createTableFromAST(
        storage->renameInMemory(ast_create_query);
        return {ast_create_query.table, storage};
    }
-    /// We do not directly use `InterpreterCreateQuery::execute`, because
-    /// - the database has not been loaded yet;
-    /// - the code is simpler, since the query is already brought to a suitable form.
-    if (!ast_create_query.columns_list || !ast_create_query.columns_list->columns)
-        throw Exception("Missing definition of columns.", ErrorCodes::EMPTY_LIST_OF_COLUMNS_PASSED);

-    ColumnsDescription columns = InterpreterCreateQuery::getColumnsDescription(*ast_create_query.columns_list->columns, context, true);
-    ConstraintsDescription constraints = InterpreterCreateQuery::getConstraintsDescription(ast_create_query.columns_list->constraints);
+    ColumnsDescription columns;
+    ConstraintsDescription constraints;
+
+    if (!ast_create_query.is_dictionary)
+    {
+        /// We do not directly use `InterpreterCreateQuery::execute`, because
+        /// - the database has not been loaded yet;
+        /// - the code is simpler, since the query is already brought to a suitable form.
+        if (!ast_create_query.columns_list || !ast_create_query.columns_list->columns)
+            throw Exception("Missing definition of columns.", ErrorCodes::EMPTY_LIST_OF_COLUMNS_PASSED);
+
+        columns = InterpreterCreateQuery::getColumnsDescription(*ast_create_query.columns_list->columns, context, true);
+        constraints = InterpreterCreateQuery::getConstraintsDescription(ast_create_query.columns_list->constraints);
+    }

    return
    {
@ -220,10 +226,6 @@ void DatabaseOnDisk::createTable(
    /// A race condition would be possible if a table with the same name is simultaneously created using CREATE and using ATTACH.
    /// But there is protection from it - see using DDLGuard in InterpreterCreateQuery.

-    if (isDictionaryExist(table_name))
-        throw Exception(
-            ErrorCodes::DICTIONARY_ALREADY_EXISTS, "Dictionary {}.{} already exists", backQuote(getDatabaseName()), backQuote(table_name));
-
    if (isTableExist(table_name, getContext()))
        throw Exception(
            ErrorCodes::TABLE_ALREADY_EXISTS, "Table {}.{} already exists", backQuote(getDatabaseName()), backQuote(table_name));
--- a/src/Databases/DatabaseOrdinary.cpp
+++ b/src/Databases/DatabaseOrdinary.cpp
@ -43,13 +43,15 @@ namespace
        const String & metadata_path,
        bool has_force_restore_data_flag)
    {
-        assert(!query.is_dictionary);
        try
        {
-            String table_name;
-            StoragePtr table;
-            std::tie(table_name, table)
-                = createTableFromAST(query, database_name, database.getTableDataPath(query), context, has_force_restore_data_flag);
+            auto [table_name, table] = createTableFromAST(
+                query,
+                database_name,
+                database.getTableDataPath(query),
+                context,
+                has_force_restore_data_flag);
+
            database.attachTable(table_name, table, database.getTableDataPath(query));
        }
        catch (Exception & e)
@ -61,28 +63,6 @@ namespace
        }
    }

-
-    void tryAttachDictionary(const ASTPtr & query, DatabaseOrdinary & database, const String & metadata_path, ContextPtr context)
-    {
-        auto & create_query = query->as<ASTCreateQuery &>();
-        assert(create_query.is_dictionary);
-        try
-        {
-            Poco::File meta_file(metadata_path);
-            auto config = getDictionaryConfigurationFromAST(create_query, context, database.getDatabaseName());
-            time_t modification_time = meta_file.getLastModified().epochTime();
-            database.attachDictionary(create_query.table, DictionaryAttachInfo{query, config, modification_time});
-        }
-        catch (Exception & e)
-        {
-            e.addMessage(
-                "Cannot attach dictionary " + backQuote(database.getDatabaseName()) + "." + backQuote(create_query.table)
-                + " from metadata file " + metadata_path + " from query " + serializeAST(*query));
-            throw;
-        }
-    }
-
-
    void logAboutProgress(Poco::Logger * log, size_t processed, size_t total, AtomicStopwatch & watch)
    {
        if (processed % PRINT_MESSAGE_EACH_N_OBJECTS == 0 || watch.compareAndRestart(PRINT_MESSAGE_EACH_N_SECONDS))
@ -101,7 +81,7 @@ DatabaseOrdinary::DatabaseOrdinary(const String & name_, const String & metadata

 DatabaseOrdinary::DatabaseOrdinary(
    const String & name_, const String & metadata_path_, const String & data_path_, const String & logger, ContextPtr context_)
-    : DatabaseWithDictionaries(name_, metadata_path_, data_path_, logger, context_)
+    : DatabaseOnDisk(name_, metadata_path_, data_path_, logger, context_)
 {
 }

@ -117,7 +97,7 @@ void DatabaseOrdinary::loadStoredObjects(ContextPtr local_context, bool has_forc

    size_t total_dictionaries = 0;

-    auto process_metadata = [context_weak = ContextWeakPtr(local_context), &file_names, &total_dictionaries, &file_names_mutex, this](
+    auto process_metadata = [&file_names, &total_dictionaries, &file_names_mutex, this](
                                const String & file_name)
    {
        fs::path path(getMetadataPath());
@ -164,7 +144,6 @@ void DatabaseOrdinary::loadStoredObjects(ContextPtr local_context, bool has_forc

    AtomicStopwatch watch;
    std::atomic<size_t> tables_processed{0};
-    std::atomic<size_t> dictionaries_processed{0};

    ThreadPool pool;

@ -176,23 +155,12 @@ void DatabaseOrdinary::loadStoredObjects(ContextPtr local_context, bool has_forc
    /// loading of its config only, it doesn't involve loading the dictionary itself.

    /// Attach dictionaries.
-    for (const auto & [name, query] : file_names)
-    {
-        auto create_query = query->as<const ASTCreateQuery &>();
-        if (create_query.is_dictionary)
-        {
-            tryAttachDictionary(query, *this, getMetadataPath() + name, local_context);
-
-            /// Messages, so that it's not boring to wait for the server to load for a long time.
-            logAboutProgress(log, ++dictionaries_processed, total_dictionaries, watch);
-        }
-    }
-
-    /// Attach tables.
    for (const auto & name_with_query : file_names)
    {
        const auto & create_query = name_with_query.second->as<const ASTCreateQuery &>();
-        if (!create_query.is_dictionary)
+
+        if (create_query.is_dictionary)
+        {
            pool.scheduleOrThrowOnError([&]()
            {
                tryAttachTable(
@ -206,6 +174,32 @@ void DatabaseOrdinary::loadStoredObjects(ContextPtr local_context, bool has_forc
                /// Messages, so that it's not boring to wait for the server to load for a long time.
                logAboutProgress(log, ++tables_processed, total_tables, watch);
            });
+        }
+    }
+
+    pool.wait();
+
+    /// Attach tables.
+    for (const auto & name_with_query : file_names)
+    {
+        const auto & create_query = name_with_query.second->as<const ASTCreateQuery &>();
+
+        if (!create_query.is_dictionary)
+        {
+            pool.scheduleOrThrowOnError([&]()
+            {
+                tryAttachTable(
+                    local_context,
+                    create_query,
+                    *this,
+                    database_name,
+                    getMetadataPath() + name_with_query.first,
+                    has_force_restore_data_flag);
+
+                /// Messages, so that it's not boring to wait for the server to load for a long time.
+                logAboutProgress(log, ++tables_processed, total_tables, watch);
+            });
+        }
    }

    pool.wait();
--- a/src/Databases/DatabaseOrdinary.h
+++ b/src/Databases/DatabaseOrdinary.h
@ -1,6 +1,6 @@
 #pragma once

-#include <Databases/DatabaseWithDictionaries.h>
+#include <Databases/DatabaseOnDisk.h>
 #include <Common/ThreadPool.h>


@ -11,7 +11,7 @@ namespace DB
  * It stores tables list in filesystem using list of .sql files,
  *  that contain declaration of table represented by SQL ATTACH TABLE query.
  */
-class DatabaseOrdinary : public DatabaseWithDictionaries
+class DatabaseOrdinary : public DatabaseOnDisk
 {
 public:
    DatabaseOrdinary(const String & name_, const String & metadata_path_, ContextPtr context);
--- a/src/Databases/DatabaseReplicated.cpp
+++ b/src/Databases/DatabaseReplicated.cpp
@ -511,9 +511,10 @@ void DatabaseReplicated::recoverLostReplica(const ZooKeeperPtr & current_zookeep
        executeQuery(query, query_context, true);
    }

-    size_t dropped_dicts = 0;
    size_t moved_tables = 0;
    std::vector<UUID> dropped_tables;
+    size_t dropped_dictionaries = 0;
+
    for (const auto & table_name : tables_to_detach)
    {
        DDLGuardPtr table_guard = DatabaseCatalog::instance().getDDLGuard(db_name, table_name);
@ -521,17 +522,13 @@ void DatabaseReplicated::recoverLostReplica(const ZooKeeperPtr & current_zookeep
            throw Exception(ErrorCodes::UNKNOWN_DATABASE, "Database was renamed, will retry");

        auto table = tryGetTable(table_name, getContext());
-        if (isDictionaryExist(table_name))
-        {
-            /// We can safely drop any dictionaries because they do not store data
-            LOG_DEBUG(log, "Will DROP DICTIONARY {}", backQuoteIfNeed(table_name));
-            DatabaseAtomic::removeDictionary(getContext(), table_name);
-            ++dropped_dicts;
-        }
-        else if (!table->storesDataOnDisk())
+
+        if (!table->storesDataOnDisk())
        {
            LOG_DEBUG(log, "Will DROP TABLE {}, because it does not store data on disk and can be safely dropped", backQuoteIfNeed(table_name));
            dropped_tables.push_back(tryGetTableUUID(table_name));
+            dropped_dictionaries += table->isDictionary();
+
            table->shutdown();
            DatabaseAtomic::dropTable(getContext(), table_name, true);
        }
@ -550,7 +547,7 @@ void DatabaseReplicated::recoverLostReplica(const ZooKeeperPtr & current_zookeep

    if (!tables_to_detach.empty())
        LOG_WARNING(log, "Cleaned {} outdated objects: dropped {} dictionaries and {} tables, moved {} tables",
-                    tables_to_detach.size(), dropped_dicts, dropped_tables.size(), moved_tables);
+                    tables_to_detach.size(), dropped_dictionaries, dropped_tables.size() - dropped_dictionaries, moved_tables);

    /// Now database is cleared from outdated tables, let's rename ReplicatedMergeTree tables to actual names
    for (const auto & old_to_new : replicated_tables_to_rename)
@ -766,33 +763,6 @@ void DatabaseReplicated::commitAlterTable(const StorageID & table_id,
    DatabaseAtomic::commitAlterTable(table_id, table_metadata_tmp_path, table_metadata_path, statement, query_context);
 }

-void DatabaseReplicated::createDictionary(ContextPtr local_context,
-                                          const String & dictionary_name,
-                                          const ASTPtr & query)
-{
-    auto txn = local_context->getZooKeeperMetadataTransaction();
-    assert(!ddl_worker->isCurrentlyActive() || txn);
-    if (txn && txn->isInitialQuery())
-    {
-        String metadata_zk_path = zookeeper_path + "/metadata/" + escapeForFileName(dictionary_name);
-        String statement = getObjectDefinitionFromCreateQuery(query->clone());
-        txn->addOp(zkutil::makeCreateRequest(metadata_zk_path, statement, zkutil::CreateMode::Persistent));
-    }
-    DatabaseAtomic::createDictionary(local_context, dictionary_name, query);
-}
-
-void DatabaseReplicated::removeDictionary(ContextPtr local_context, const String & dictionary_name)
-{
-    auto txn = local_context->getZooKeeperMetadataTransaction();
-    assert(!ddl_worker->isCurrentlyActive() || txn);
-    if (txn && txn->isInitialQuery())
-    {
-        String metadata_zk_path = zookeeper_path + "/metadata/" + escapeForFileName(dictionary_name);
-        txn->addOp(zkutil::makeRemoveRequest(metadata_zk_path, -1));
-    }
-    DatabaseAtomic::removeDictionary(local_context, dictionary_name);
-}
-
 void DatabaseReplicated::detachTablePermanently(ContextPtr local_context, const String & table_name)
 {
    auto txn = local_context->getZooKeeperMetadataTransaction();
--- a/src/Databases/DatabaseReplicated.h
+++ b/src/Databases/DatabaseReplicated.h
@ -40,10 +40,6 @@ public:
    void commitAlterTable(const StorageID & table_id,
                          const String & table_metadata_tmp_path, const String & table_metadata_path,
                          const String & statement, ContextPtr query_context) override;
-    void createDictionary(ContextPtr context,
-                          const String & dictionary_name,
-                          const ASTPtr & query) override;
-    void removeDictionary(ContextPtr context, const String & dictionary_name) override;
    void detachTablePermanently(ContextPtr context, const String & table_name) override;
    void removeDetachedPermanentlyFlag(ContextPtr context, const String & table_name, const String & table_metadata_path, bool attach) const override;

--- a/src/Databases/DatabaseWithDictionaries.cpp
+++ b/src/Databases/DatabaseWithDictionaries.cpp
@ -1,381 +0,0 @@
-#include <Databases/DatabaseWithDictionaries.h>
-#include <Common/StatusInfo.h>
-#include <Common/ExternalLoaderStatus.h>
-#include <Interpreters/ExternalDictionariesLoader.h>
-#include <Interpreters/ExternalLoaderTempConfigRepository.h>
-#include <Interpreters/ExternalLoaderDatabaseConfigRepository.h>
-#include <Interpreters/DDLTask.h>
-#include <Dictionaries/getDictionaryConfigurationFromAST.h>
-#include <Dictionaries/DictionaryStructure.h>
-#include <Parsers/ASTCreateQuery.h>
-#include <Interpreters/Context.h>
-#include <Storages/StorageDictionary.h>
-#include <IO/WriteBufferFromFile.h>
-#include <Poco/File.h>
-#include <boost/smart_ptr/make_shared_object.hpp>
-
-
-namespace CurrentStatusInfo
-{
-    extern const Status DictionaryStatus;
-}
-
-namespace DB
-{
-
-namespace ErrorCodes
-{
-    extern const int CANNOT_GET_CREATE_DICTIONARY_QUERY;
-    extern const int TABLE_ALREADY_EXISTS;
-    extern const int UNKNOWN_DICTIONARY;
-    extern const int DICTIONARY_ALREADY_EXISTS;
-    extern const int FILE_DOESNT_EXIST;
-}
-
-
-void DatabaseWithDictionaries::attachDictionary(const String & dictionary_name, const DictionaryAttachInfo & attach_info)
-{
-    auto dict_id = StorageID(attach_info.create_query);
-    String internal_name = dict_id.getInternalDictionaryName();
-    assert(attach_info.create_query->as<const ASTCreateQuery &>().table == dictionary_name);
-    assert(!dict_id.database_name.empty());
-    {
-        std::unique_lock lock(mutex);
-        auto [it, inserted] = dictionaries.emplace(dictionary_name, attach_info);
-        if (!inserted)
-            throw Exception(ErrorCodes::DICTIONARY_ALREADY_EXISTS,
-                            "Dictionary {} already exists.", dict_id.getNameForLogs());
-
-        /// Attach the dictionary as table too.
-        try
-        {
-            /// TODO Make StorageDictionary an owner of IDictionary objects.
-            /// All DDL operations with dictionaries will work with StorageDictionary table,
-            /// and StorageDictionary will be responsible for loading of DDL dictionaries.
-            /// ExternalLoaderDatabaseConfigRepository and other hacks related to ExternalLoader
-            /// will not be longer required.
-            attachTableUnlocked(
-                dictionary_name,
-                StorageDictionary::create(
-                    dict_id,
-                    internal_name,
-                    ExternalDictionariesLoader::getDictionaryStructure(*attach_info.config),
-                    StorageDictionary::Location::SameDatabaseAndNameAsDictionary),
-                lock);
-        }
-        catch (...)
-        {
-            dictionaries.erase(it);
-            throw;
-        }
-    }
-
-    CurrentStatusInfo::set(CurrentStatusInfo::DictionaryStatus, internal_name, static_cast<Int8>(ExternalLoaderStatus::NOT_LOADED));
-
-    /// We want ExternalLoader::reloadConfig() to find out that the dictionary's config
-    /// has been added and in case `dictionaries_lazy_load == false` to load the dictionary.
-    reloadDictionaryConfig(internal_name);
-}
-
-void DatabaseWithDictionaries::detachDictionary(const String & dictionary_name)
-{
-    DictionaryAttachInfo attach_info;
-    detachDictionaryImpl(dictionary_name, attach_info);
-}
-
-void DatabaseWithDictionaries::detachDictionaryImpl(const String & dictionary_name, DictionaryAttachInfo & attach_info)
-{
-    auto dict_id = StorageID::createEmpty();
-    String internal_name;
-
-    {
-        std::unique_lock lock(mutex);
-        auto it = dictionaries.find(dictionary_name);
-        if (it == dictionaries.end())
-            throw Exception(ErrorCodes::UNKNOWN_DICTIONARY,
-                            "Dictionary {}.{} doesn't exist.", database_name, dictionary_name);
-        dict_id = StorageID(it->second.create_query);
-        internal_name = dict_id.getInternalDictionaryName();
-        assert(dict_id.table_name == dictionary_name);
-        assert(!dict_id.database_name.empty());
-
-        attach_info = std::move(it->second);
-        dictionaries.erase(it);
-
-        /// Detach the dictionary as table too.
-        try
-        {
-            if (!dict_id.hasUUID())
-                detachTableUnlocked(dictionary_name, lock);
-        }
-        catch (...)
-        {
-            dictionaries.emplace(dictionary_name, std::move(attach_info));
-            throw;
-        }
-    }
-
-    CurrentStatusInfo::unset(CurrentStatusInfo::DictionaryStatus, internal_name);
-
-    /// We want ExternalLoader::reloadConfig() to find out that the dictionary's config
-    /// has been removed and to unload the dictionary.
-    reloadDictionaryConfig(internal_name);
-
-    if (dict_id.hasUUID())
-        detachTable(dictionary_name);
-}
-
-void DatabaseWithDictionaries::createDictionary(ContextPtr local_context, const String & dictionary_name, const ASTPtr & query)
-{
-    const auto & settings = local_context->getSettingsRef();
-
-    /** The code is based on the assumption that all threads share the same order of operations:
-      * - create the .sql.tmp file;
-      * - add the dictionary to ExternalDictionariesLoader;
-      * - load the dictionary in case dictionaries_lazy_load == false;
-      * - attach the dictionary;
-      * - rename .sql.tmp to .sql.
-      */
-
-    auto dict_id = StorageID(query);
-    assert(query->as<const ASTCreateQuery &>().table == dictionary_name);
-    assert(!dict_id.database_name.empty());
-
-    /// A race condition would be possible if a dictionary with the same name is simultaneously created using CREATE and using ATTACH.
-    /// But there is protection from it - see using DDLGuard in InterpreterCreateQuery.
-    if (isDictionaryExist(dictionary_name))
-        throw Exception(ErrorCodes::DICTIONARY_ALREADY_EXISTS, "Dictionary {} already exists.", dict_id.getFullTableName());
-
-    /// A dictionary with the same full name could be defined in *.xml config files.
-    if (external_loader.getCurrentStatus(dict_id.getFullNameNotQuoted()) != ExternalLoader::Status::NOT_EXIST)
-        throw Exception(ErrorCodes::DICTIONARY_ALREADY_EXISTS,
-                        "Dictionary {} already exists.", dict_id.getFullNameNotQuoted());
-
-    if (isTableExist(dictionary_name, getContext()))
-        throw Exception(ErrorCodes::TABLE_ALREADY_EXISTS, "Table {} already exists.", dict_id.getFullTableName());
-
-    String dictionary_metadata_path = getObjectMetadataPath(dictionary_name);
-    String dictionary_metadata_tmp_path = dictionary_metadata_path + ".tmp";
-    String statement = getObjectDefinitionFromCreateQuery(query);
-
-    {
-        /// Exclusive flags guarantees, that table is not created right now in another thread. Otherwise, exception will be thrown.
-        WriteBufferFromFile out(dictionary_metadata_tmp_path, statement.size(), O_WRONLY | O_CREAT | O_EXCL);
-        writeString(statement, out);
-        out.next();
-        if (settings.fsync_metadata)
-            out.sync();
-        out.close();
-    }
-
-    bool succeeded = false;
-    bool uuid_locked = false;
-    SCOPE_EXIT({
-        if (!succeeded)
-        {
-            if (uuid_locked)
-                DatabaseCatalog::instance().removeUUIDMappingFinally(dict_id.uuid);
-            Poco::File(dictionary_metadata_tmp_path).remove();
-        }
-    });
-
-    if (dict_id.uuid != UUIDHelpers::Nil)
-    {
-        DatabaseCatalog::instance().addUUIDMapping(dict_id.uuid);
-        uuid_locked = true;
-    }
-
-    /// Add a temporary repository containing the dictionary.
-    /// We need this temp repository to try loading the dictionary before actually attaching it to the database.
-    auto temp_repository = external_loader.addConfigRepository(std::make_unique<ExternalLoaderTempConfigRepository>(
-        getDatabaseName(), dictionary_metadata_tmp_path, getDictionaryConfigurationFromAST(query->as<const ASTCreateQuery &>(), local_context)));
-
-    bool lazy_load = local_context->getConfigRef().getBool("dictionaries_lazy_load", true);
-    if (!lazy_load)
-    {
-        /// load() is called here to force loading the dictionary, wait until the loading is finished,
-        /// and throw an exception if the loading is failed.
-        external_loader.load(dict_id.getInternalDictionaryName());
-    }
-
-    auto config = getDictionaryConfigurationFromAST(query->as<const ASTCreateQuery &>(), local_context);
-    attachDictionary(dictionary_name, DictionaryAttachInfo{query, config, time(nullptr)});
-    SCOPE_EXIT({
-        if (!succeeded)
-            detachDictionary(dictionary_name);
-    });
-
-    auto txn = local_context->getZooKeeperMetadataTransaction();
-    if (txn && !local_context->isInternalSubquery())
-        txn->commit();      /// Commit point (a sort of) for Replicated database
-
-    /// If it was ATTACH query and file with dictionary metadata already exist
-    /// (so, ATTACH is done after DETACH), then rename atomically replaces old file with new one.
-    Poco::File(dictionary_metadata_tmp_path).renameTo(dictionary_metadata_path);
-
-    /// ExternalDictionariesLoader doesn't know we renamed the metadata path.
-    /// That's why we have to call ExternalLoader::reloadConfig() here.
-    reloadDictionaryConfig(dict_id.getInternalDictionaryName());
-
-    /// Everything's ok.
-    succeeded = true;
-}
-
-void DatabaseWithDictionaries::removeDictionary(ContextPtr local_context, const String & dictionary_name)
-{
-    DictionaryAttachInfo attach_info;
-    detachDictionaryImpl(dictionary_name, attach_info);
-
-    try
-    {
-        String dictionary_metadata_path = getObjectMetadataPath(dictionary_name);
-
-        auto txn = local_context->getZooKeeperMetadataTransaction();
-        if (txn && !local_context->isInternalSubquery())
-            txn->commit();      /// Commit point (a sort of) for Replicated database
-
-        Poco::File(dictionary_metadata_path).remove();
-        CurrentStatusInfo::unset(CurrentStatusInfo::DictionaryStatus,
-                                 StorageID(attach_info.create_query).getInternalDictionaryName());
-    }
-    catch (...)
-    {
-        /// If remove was not possible for some reason
-        attachDictionary(dictionary_name, attach_info);
-        throw;
-    }
-
-    UUID dict_uuid = attach_info.create_query->as<ASTCreateQuery>()->uuid;
-    if (dict_uuid != UUIDHelpers::Nil)
-        DatabaseCatalog::instance().removeUUIDMappingFinally(dict_uuid);
-}
-
-DatabaseDictionariesIteratorPtr DatabaseWithDictionaries::getDictionariesIterator(const FilterByNameFunction & filter_by_dictionary_name)
-{
-    std::lock_guard lock(mutex);
-    DictionariesWithID filtered_dictionaries;
-    for (const auto & dictionary : dictionaries)
-    {
-        if (filter_by_dictionary_name && !filter_by_dictionary_name(dictionary.first))
-            continue;
-        filtered_dictionaries.emplace_back();
-        filtered_dictionaries.back().first = dictionary.first;
-        filtered_dictionaries.back().second = dictionary.second.create_query->as<const ASTCreateQuery &>().uuid;
-    }
-    return std::make_unique<DatabaseDictionariesSnapshotIterator>(std::move(filtered_dictionaries), database_name);
-}
-
-bool DatabaseWithDictionaries::isDictionaryExist(const String & dictionary_name) const
-{
-    std::lock_guard lock(mutex);
-    return dictionaries.find(dictionary_name) != dictionaries.end();
-}
-
-ASTPtr DatabaseWithDictionaries::getCreateDictionaryQueryImpl(
-        const String & dictionary_name,
-        bool throw_on_error) const
-{
-    {
-        /// Try to get create query ifg for an attached dictionary.
-        std::lock_guard lock{mutex};
-        auto it = dictionaries.find(dictionary_name);
-        if (it != dictionaries.end())
-        {
-            ASTPtr ast = it->second.create_query->clone();
-            auto & create_query = ast->as<ASTCreateQuery &>();
-            create_query.attach = false;
-            create_query.database = database_name;
-            return ast;
-        }
-    }
-
-    /// Try to get create query for non-attached dictionary.
-    ASTPtr ast;
-    try
-    {
-        auto dictionary_metadata_path = getObjectMetadataPath(dictionary_name);
-        ast = getCreateQueryFromMetadata(dictionary_metadata_path, throw_on_error);
-    }
-    catch (const Exception & e)
-    {
-        if (throw_on_error && (e.code() != ErrorCodes::FILE_DOESNT_EXIST))
-            throw;
-    }
-
-    if (ast)
-    {
-        const auto * create_query = ast->as<const ASTCreateQuery>();
-        if (create_query && create_query->is_dictionary)
-            return ast;
-    }
-    if (throw_on_error)
-        throw Exception{"Dictionary " + backQuote(dictionary_name) + " doesn't exist",
-                        ErrorCodes::CANNOT_GET_CREATE_DICTIONARY_QUERY};
-    return nullptr;
-}
-
-Poco::AutoPtr<Poco::Util::AbstractConfiguration> DatabaseWithDictionaries::getDictionaryConfiguration(const String & dictionary_name) const
-{
-    std::lock_guard lock(mutex);
-    auto it = dictionaries.find(dictionary_name);
-    if (it != dictionaries.end())
-        return it->second.config;
-    throw Exception("Dictionary " + backQuote(dictionary_name) + " doesn't exist", ErrorCodes::UNKNOWN_DICTIONARY);
-}
-
-time_t DatabaseWithDictionaries::getObjectMetadataModificationTime(const String & object_name) const
-{
-    {
-        std::lock_guard lock(mutex);
-        auto it = dictionaries.find(object_name);
-        if (it != dictionaries.end())
-            return it->second.modification_time;
-    }
-    return DatabaseOnDisk::getObjectMetadataModificationTime(object_name);
-}
-
-
-bool DatabaseWithDictionaries::empty() const
-{
-    std::lock_guard lock{mutex};
-    return tables.empty() && dictionaries.empty();
-}
-
-void DatabaseWithDictionaries::reloadDictionaryConfig(const String & full_name)
-{
-    /// Ensure that this database is attached to ExternalLoader as a config repository.
-    if (!database_as_config_repo_for_external_loader.load())
-    {
-        auto repository = std::make_unique<ExternalLoaderDatabaseConfigRepository>(*this, getContext());
-        auto remove_repository_callback = external_loader.addConfigRepository(std::move(repository));
-        database_as_config_repo_for_external_loader = boost::make_shared<ext::scope_guard>(std::move(remove_repository_callback));
-    }
-
-    external_loader.reloadConfig(getDatabaseName(), full_name);
-}
-
-
-void DatabaseWithDictionaries::shutdown()
-{
-    {
-        std::lock_guard lock(mutex);
-        dictionaries.clear();
-    }
-
-    /// Invoke removing the database from ExternalLoader.
-    database_as_config_repo_for_external_loader = nullptr;
-
-    DatabaseOnDisk::shutdown();
-}
-
-
-DatabaseWithDictionaries::DatabaseWithDictionaries(
-    const String & name, const String & metadata_path_, const String & data_path_, const String & logger, ContextPtr context_)
-    : DatabaseOnDisk(name, metadata_path_, data_path_, logger, context_)
-    , external_loader(context_->getExternalDictionariesLoader())
-{
-}
-
-DatabaseWithDictionaries::~DatabaseWithDictionaries() = default;
-
-}
--- a/src/Databases/DatabaseWithDictionaries.h
+++ b/src/Databases/DatabaseWithDictionaries.h
@ -1,55 +0,0 @@
-#pragma once
-#include <Databases/DatabaseOnDisk.h>
-#include <boost/smart_ptr/atomic_shared_ptr.hpp>
-#include <ext/scope_guard.h>
-
-namespace DB
-{
-
-class Context;
-class ExternalDictionariesLoader;
-
-
-class DatabaseWithDictionaries : public DatabaseOnDisk
-{
-public:
-    void attachDictionary(const String & dictionary_name, const DictionaryAttachInfo & attach_info) override;
-
-    void detachDictionary(const String & dictionary_name) override;
-
-    void createDictionary(ContextPtr context,
-                          const String & dictionary_name,
-                          const ASTPtr & query) override;
-
-    void removeDictionary(ContextPtr context, const String & dictionary_name) override;
-
-    bool isDictionaryExist(const String & dictionary_name) const override;
-
-    DatabaseDictionariesIteratorPtr getDictionariesIterator(const FilterByNameFunction & filter_by_dictionary_name) override;
-
-    Poco::AutoPtr<Poco::Util::AbstractConfiguration> getDictionaryConfiguration(const String & /*name*/) const override;
-
-    time_t getObjectMetadataModificationTime(const String & object_name) const override;
-
-    bool empty() const override;
-
-    void shutdown() override;
-
-    ~DatabaseWithDictionaries() override;
-
-protected:
-    DatabaseWithDictionaries(const String & name, const String & metadata_path_, const String & data_path_, const String & logger, ContextPtr context);
-
-    ASTPtr getCreateDictionaryQueryImpl(const String & dictionary_name, bool throw_on_error) const override;
-
-    std::unordered_map<String, DictionaryAttachInfo> dictionaries;
-    const ExternalDictionariesLoader & external_loader;
-
-private:
-    void detachDictionaryImpl(const String & dictionary_name, DictionaryAttachInfo & attach_info);
-    void reloadDictionaryConfig(const String & full_name);
-
-    boost::atomic_shared_ptr<ext::scope_guard> database_as_config_repo_for_external_loader;
-};
-
-}
--- a/src/Databases/IDatabase.h
+++ b/src/Databases/IDatabase.h
@ -29,7 +29,6 @@ namespace ErrorCodes
 {
    extern const int NOT_IMPLEMENTED;
    extern const int CANNOT_GET_CREATE_TABLE_QUERY;
-    extern const int CANNOT_GET_CREATE_DICTIONARY_QUERY;
 }

 class IDatabaseTablesIterator
@ -95,38 +94,7 @@ public:
    const StoragePtr & table() const override { return it->second; }
 };

-/// Copies list of dictionaries and iterates through such snapshot.
-class DatabaseDictionariesSnapshotIterator
-{
-private:
-    DictionariesWithID dictionaries;
-    DictionariesWithID::iterator it;
-    String database_name;
-
-public:
-    DatabaseDictionariesSnapshotIterator() = default;
-    DatabaseDictionariesSnapshotIterator(DictionariesWithID & dictionaries_, const String & database_name_)
-    : dictionaries(dictionaries_), it(dictionaries.begin()), database_name(database_name_)
-    {
-    }
-    DatabaseDictionariesSnapshotIterator(DictionariesWithID && dictionaries_, const String & database_name_)
-    : dictionaries(dictionaries_), it(dictionaries.begin()), database_name(database_name_)
-    {
-    }
-
-    void next() { ++it; }
-
-    bool isValid() const { return !dictionaries.empty() && it != dictionaries.end(); }
-
-    const String & name() const { return it->first; }
-
-    const UUID & uuid() const { return it->second; }
-
-    const String & databaseName() const { assert(!database_name.empty()); return database_name; }
-};
-
 using DatabaseTablesIteratorPtr = std::unique_ptr<IDatabaseTablesIterator>;
-using DatabaseDictionariesIteratorPtr = std::unique_ptr<DatabaseDictionariesSnapshotIterator>;


 /** Database engine.
@ -158,12 +126,6 @@ public:
    /// Check the existence of the table.
    virtual bool isTableExist(const String & name, ContextPtr context) const = 0;

-    /// Check the existence of the dictionary
-    virtual bool isDictionaryExist(const String & /*name*/) const
-    {
-        return false;
-    }
-
    /// Get the table for work. Return nullptr if there is no table.
    virtual StoragePtr tryGetTable(const String & name, ContextPtr context) const = 0;

@ -175,12 +137,6 @@ public:
    /// It is possible to have "hidden" tables that are not visible when passing through, but are visible if you get them by name using the functions above.
    virtual DatabaseTablesIteratorPtr getTablesIterator(ContextPtr context, const FilterByNameFunction & filter_by_table_name = {}) = 0;

-    /// Get an iterator to pass through all the dictionaries.
-    virtual DatabaseDictionariesIteratorPtr getDictionariesIterator([[maybe_unused]] const FilterByNameFunction & filter_by_dictionary_name = {})
-    {
-        return std::make_unique<DatabaseDictionariesSnapshotIterator>();
-    }
-
    /// Is the database empty.
    virtual bool empty() const = 0;

@ -194,15 +150,6 @@ public:
        throw Exception("There is no CREATE TABLE query for Database" + getEngineName(), ErrorCodes::NOT_IMPLEMENTED);
    }

-    /// Add the dictionary to the database. Record its presence in the metadata.
-    virtual void createDictionary(
-        ContextPtr /*context*/,
-        const String & /*dictionary_name*/,
-        const ASTPtr & /*query*/)
-    {
-        throw Exception("There is no CREATE DICTIONARY query for Database" + getEngineName(), ErrorCodes::NOT_IMPLEMENTED);
-    }
-
    /// Delete the table from the database, drop table and delete the metadata.
    virtual void dropTable(
        ContextPtr /*context*/,
@ -212,14 +159,6 @@ public:
        throw Exception("There is no DROP TABLE query for Database" + getEngineName(), ErrorCodes::NOT_IMPLEMENTED);
    }

-    /// Delete the dictionary from the database. Delete the metadata.
-    virtual void removeDictionary(
-        ContextPtr /*context*/,
-        const String & /*dictionary_name*/)
-    {
-        throw Exception("There is no DROP DICTIONARY query for Database" + getEngineName(), ErrorCodes::NOT_IMPLEMENTED);
-    }
-
    /// Add a table to the database, but do not add it to the metadata. The database may not support this method.
    ///
    /// Note: ATTACH TABLE statement actually uses createTable method.
@ -228,25 +167,12 @@ public:
        throw Exception("There is no ATTACH TABLE query for Database" + getEngineName(), ErrorCodes::NOT_IMPLEMENTED);
    }

-    /// Add dictionary to the database, but do not add it to the metadata. The database may not support this method.
-    /// If dictionaries_lazy_load is false it also starts loading the dictionary asynchronously.
-    virtual void attachDictionary(const String & /* dictionary_name */, const DictionaryAttachInfo & /* attach_info */)
-    {
-        throw Exception("There is no ATTACH DICTIONARY query for Database" + getEngineName(), ErrorCodes::NOT_IMPLEMENTED);
-    }
-
    /// Forget about the table without deleting it, and return it. The database may not support this method.
    virtual StoragePtr detachTable(const String & /*name*/)
    {
        throw Exception("There is no DETACH TABLE query for Database" + getEngineName(), ErrorCodes::NOT_IMPLEMENTED);
    }

-    /// Forget about the dictionary without deleting it. The database may not support this method.
-    virtual void detachDictionary(const String & /*name*/)
-    {
-        throw Exception("There is no DETACH DICTIONARY query for Database" + getEngineName(), ErrorCodes::NOT_IMPLEMENTED);
-    }
-
    /// Forget about the table without deleting it's data, but rename metadata file to prevent reloading it
    /// with next restart. The database may not support this method.
    virtual void detachTablePermanently(ContextPtr /*context*/, const String & /*name*/)
@ -295,22 +221,6 @@ public:
        return getCreateTableQueryImpl(name, context, true);
    }

-    /// Get the CREATE DICTIONARY query for the dictionary. Returns nullptr if dictionary doesn't exists.
-    ASTPtr tryGetCreateDictionaryQuery(const String & name) const noexcept
-    {
-        return getCreateDictionaryQueryImpl(name, false);
-    }
-
-    ASTPtr getCreateDictionaryQuery(const String & name) const
-    {
-        return getCreateDictionaryQueryImpl(name, true);
-    }
-
-    virtual Poco::AutoPtr<Poco::Util::AbstractConfiguration> getDictionaryConfiguration(const String & /*name*/) const
-    {
-        throw Exception(getEngineName() + ": getDictionaryConfiguration() is not supported", ErrorCodes::NOT_IMPLEMENTED);
-    }
-
    /// Get the CREATE DATABASE query for current database.
    virtual ASTPtr getCreateDatabaseQuery() const = 0;

@ -364,13 +274,6 @@ protected:
        return nullptr;
    }

-    virtual ASTPtr getCreateDictionaryQueryImpl(const String & /*name*/, bool throw_on_error) const
-    {
-        if (throw_on_error)
-            throw Exception("There is no SHOW CREATE DICTIONARY query for Database" + getEngineName(), ErrorCodes::CANNOT_GET_CREATE_DICTIONARY_QUERY);
-        return nullptr;
-    }
-
    mutable std::mutex mutex;
    String database_name;
 };
--- a/Show More
+++ b/Show More
				`@ -0,0 +1 @@`
				`../../../../en/sql-reference/aggregate-functions/reference/max.md`