From 0093425201b1532e6da17326d8984708ddda0fe8 Mon Sep 17 00:00:00 2001
From: Vitaly Baranov <vitbar@yandex-team.ru>
Date: Tue, 21 Jul 2020 22:31:27 +0300
Subject: [PATCH 01/25] CREATE USER IF NOT EXISTS now doesn't throw exception
 if the user exists.

---
 src/Access/IAccessStorage.cpp                 | 274 ++++++++++--------
 .../0_stateless/01292_create_user.reference   |   9 +
 .../queries/0_stateless/01292_create_user.sql |  18 ++
 3 files changed, 181 insertions(+), 120 deletions(-)

diff --git a/src/Access/IAccessStorage.cpp b/src/Access/IAccessStorage.cpp
index 6813b5eb558..ffedfb038a4 100644
--- a/src/Access/IAccessStorage.cpp
+++ b/src/Access/IAccessStorage.cpp
@@ -1,6 +1,4 @@
 #include <Access/IAccessStorage.h>
-#include <Access/User.h>
-#include <Access/Role.h>
 #include <Common/Exception.h>
 #include <Common/quoteString.h>
 #include <IO/WriteHelpers.h>
@@ -39,110 +37,71 @@ namespace
     }
 
 
-    template <typename Func, typename ResultType = std::result_of_t<Func()>>
-    ResultType doTry(const Func & func)
+    template <typename Func>
+    bool tryCall(const Func & function)
     {
         try
         {
-            return func();
+            function();
+            return true;
         }
-        catch (Exception &)
+        catch (...)
         {
-            return {};
+            return false;
         }
     }
 
 
-    template <bool ignore_errors, typename T, typename ApplyFunc, typename GetNameFunc = std::nullptr_t,
-              typename ResultTypeOfApplyFunc = std::result_of_t<ApplyFunc(T)>,
-              typename ResultType = std::conditional_t<std::is_same_v<ResultTypeOfApplyFunc, void>, void, std::vector<ResultTypeOfApplyFunc>>>
-    ResultType applyToMultipleEntities(
-        const std::vector<T> & multiple_entities,
-        const ApplyFunc & apply_function,
-        const char * error_message_format [[maybe_unused]] = nullptr,
-        const GetNameFunc & get_name_function [[maybe_unused]] = nullptr)
+    class ErrorsTracker
     {
-        std::optional<Exception> exception;
-        std::vector<bool> success;
+    public:
+        explicit ErrorsTracker(size_t count_) { succeed.reserve(count_); }
 
-        auto helper = [&](const auto & apply_and_store_result_function)
+        template <typename Func>
+        bool tryCall(const Func & func)
         {
-            for (size_t i = 0; i != multiple_entities.size(); ++i)
+            try
             {
-                try
-                {
-                    apply_and_store_result_function(multiple_entities[i]);
-                    if constexpr (!ignore_errors)
-                        success[i] = true;
-                }
-                catch (Exception & e)
-                {
-                    if (!ignore_errors && !exception)
-                        exception.emplace(e);
-                }
-                catch (Poco::Exception & e)
-                {
-                    if (!ignore_errors && !exception)
-                        exception.emplace(Exception::CreateFromPocoTag{}, e);
-                }
-                catch (std::exception & e)
-                {
-                    if (!ignore_errors && !exception)
-                        exception.emplace(Exception::CreateFromSTDTag{}, e);
-                }
+                func();
             }
-        };
-
-        if constexpr (std::is_same_v<ResultType, void>)
-        {
-            if (multiple_entities.empty())
-                return;
-
-            if (multiple_entities.size() == 1)
+            catch (Exception & e)
             {
-                apply_function(multiple_entities.front());
-                return;
+                if (!exception)
+                    exception.emplace(e);
+                succeed.push_back(false);
+                return false;
             }
-
-            if constexpr (!ignore_errors)
-                success.resize(multiple_entities.size(), false);
-
-            helper(apply_function);
-
-            if (ignore_errors || !exception)
-                return;
-        }
-        else
-        {
-            ResultType result;
-            if (multiple_entities.empty())
-                return result;
-
-            if (multiple_entities.size() == 1)
+            catch (Poco::Exception & e)
             {
-                result.emplace_back(apply_function(multiple_entities.front()));
-                return result;
+                if (!exception)
+                    exception.emplace(Exception::CreateFromPocoTag{}, e);
+                succeed.push_back(false);
+                return false;
             }
-
-            result.reserve(multiple_entities.size());
-            if constexpr (!ignore_errors)
-                success.resize(multiple_entities.size(), false);
-
-            helper([&](const T & entity) { result.emplace_back(apply_function(entity)); });
-
-            if (ignore_errors || !exception)
-                return result;
+            catch (std::exception & e)
+            {
+                if (!exception)
+                    exception.emplace(Exception::CreateFromSTDTag{}, e);
+                succeed.push_back(false);
+                return false;
+            }
+            succeed.push_back(true);
+            return true;
         }
 
-        if constexpr (!ignore_errors)
+        bool errors() const { return exception.has_value(); }
+
+        void showErrors(const char * format, const std::function<String(size_t)> & get_name_function)
         {
+            if (!exception)
+                return;
+
             Strings succeeded_names_list;
             Strings failed_names_list;
-            for (size_t i = 0; i != multiple_entities.size(); ++i)
+            for (size_t i = 0; i != succeed.size(); ++i)
             {
-                const auto & entity = multiple_entities[i];
-                String name = get_name_function(entity);
-                if (success[i])
+                String name = get_name_function(i);
+                if (succeed[i])
                     succeeded_names_list.emplace_back(name);
                 else
                     failed_names_list.emplace_back(name);
@@ -152,14 +111,17 @@ namespace
             if (succeeded_names.empty())
                 succeeded_names = "none";
 
-            String error_message = error_message_format;
+            String error_message = format;
             boost::replace_all(error_message, "{succeeded_names}", succeeded_names);
             boost::replace_all(error_message, "{failed_names}", failed_names);
             exception->addMessage(error_message);
             exception->rethrow();
         }
-        __builtin_unreachable();
-    }
+
+    private:
+        std::vector<bool> succeed;
+        std::optional<Exception> exception;
+    };
 }
 
 
@@ -216,7 +178,11 @@ bool IAccessStorage::exists(const UUID & id) const
 
 AccessEntityPtr IAccessStorage::tryReadBase(const UUID & id) const
 {
-    return doTry([&] { return readImpl(id); });
+    AccessEntityPtr entity;
+    auto func = [&] { entity = readImpl(id); };
+    if (!tryCall(func))
+        return nullptr;
+    return entity;
 }
 
 
@@ -228,7 +194,11 @@ String IAccessStorage::readName(const UUID & id) const
 
 std::optional<String> IAccessStorage::tryReadName(const UUID & id) const
 {
-    return doTry([&] { return std::optional<String>{readNameImpl(id)}; });
+    String name;
+    auto func = [&] { name = readNameImpl(id); };
+    if (!tryCall(func))
+        return {};
+    return name;
 }
 
 
@@ -240,41 +210,77 @@ UUID IAccessStorage::insert(const AccessEntityPtr & entity)
 
 std::vector<UUID> IAccessStorage::insert(const std::vector<AccessEntityPtr> & multiple_entities)
 {
-    return applyToMultipleEntities</* ignore_errors = */ false>(
-        multiple_entities,
-        [this](const AccessEntityPtr & entity) { return insertImpl(entity, /* replace_if_exists = */ false); },
-        "Couldn't insert {failed_names}. Successfully inserted: {succeeded_names}",
-        [](const AccessEntityPtr & entity) { return entity->outputTypeAndName(); });
+    ErrorsTracker tracker(multiple_entities.size());
+
+    std::vector<UUID> ids;
+    for (const auto & entity : multiple_entities)
+    {
+        UUID id;
+        auto func = [&] { id = insertImpl(entity, /* replace_if_exists = */ false); };
+        if (tracker.tryCall(func))
+            ids.push_back(id);
+    }
+
+    if (tracker.errors())
+    {
+        auto get_name_function = [&](size_t i) { return multiple_entities[i]->outputTypeAndName(); };
+        tracker.showErrors("Couldn't insert {failed_names}. Successfully inserted: {succeeded_names}", get_name_function);
+    }
+
+    return ids;
 }
 
 
 std::optional<UUID> IAccessStorage::tryInsert(const AccessEntityPtr & entity)
 {
-    return doTry([&] { return std::optional<UUID>{insertImpl(entity, false)}; });
+    UUID id;
+    auto func = [&] { id = insertImpl(entity, /* replace_if_exists = */ false); };
+    if (!tryCall(func))
+        return {};
+    return id;
 }
 
 
 std::vector<UUID> IAccessStorage::tryInsert(const std::vector<AccessEntityPtr> & multiple_entities)
 {
-    return applyToMultipleEntities</* ignore_errors = */ true>(
-        multiple_entities,
-        [this](const AccessEntityPtr & entity) { return insertImpl(entity, /* replace_if_exists = */ false); });
+    std::vector<UUID> ids;
+    for (const auto & entity : multiple_entities)
+    {
+        UUID id;
+        auto func = [&] { id = insertImpl(entity, /* replace_if_exists = */ false); };
+        if (tryCall(func))
+            ids.push_back(id);
+    }
+    return ids;
 }
 
 
 UUID IAccessStorage::insertOrReplace(const AccessEntityPtr & entity)
 {
-    return insertImpl(entity, true);
+    return insertImpl(entity, /* replace_if_exists = */ true);
 }
 
 
 std::vector<UUID> IAccessStorage::insertOrReplace(const std::vector<AccessEntityPtr> & multiple_entities)
 {
-    return applyToMultipleEntities</* ignore_errors = */ false>(
-        multiple_entities,
-        [this](const AccessEntityPtr & entity) { return insertImpl(entity, /* replace_if_exists = */ true); },
-        "Couldn't insert {failed_names}. Successfully inserted: {succeeded_names}",
-        [](const AccessEntityPtr & entity) -> String { return entity->outputTypeAndName(); });
+    ErrorsTracker tracker(multiple_entities.size());
+
+    std::vector<UUID> ids;
+    for (const auto & entity : multiple_entities)
+    {
+        UUID id;
+        auto func = [&] { id = insertImpl(entity, /* replace_if_exists = */ true); };
+        if (tracker.tryCall(func))
+            ids.push_back(id);
+    }
+
+    if (tracker.errors())
+    {
+        auto get_name_function = [&](size_t i) { return multiple_entities[i]->outputTypeAndName(); };
+        tracker.showErrors("Couldn't insert {failed_names}. Successfully inserted: {succeeded_names}", get_name_function);
+    }
+
+    return ids;
 }
 
 
@@ -286,25 +292,39 @@ void IAccessStorage::remove(const UUID & id)
 
 void IAccessStorage::remove(const std::vector<UUID> & ids)
 {
-    applyToMultipleEntities</* ignore_errors = */ false>(
-        ids,
-        [this](const UUID & id) { removeImpl(id); },
-        "Couldn't remove {failed_names}. Successfully removed: {succeeded_names}",
-        [this](const UUID & id) { return outputTypeAndNameOrID(*this, id); });
+    ErrorsTracker tracker(ids.size());
+
+    for (const auto & id : ids)
+    {
+        auto func = [&] { removeImpl(id); };
+        tracker.tryCall(func);
+    }
+
+    if (tracker.errors())
+    {
+        auto get_name_function = [&](size_t i) { return outputTypeAndNameOrID(*this, ids[i]); };
+        tracker.showErrors("Couldn't remove {failed_names}. Successfully removed: {succeeded_names}", get_name_function);
+    }
 }
 
 
 bool IAccessStorage::tryRemove(const UUID & id)
 {
-    return doTry([&] { removeImpl(id); return true; });
+    auto func = [&] { removeImpl(id); };
+    return tryCall(func);
 }
 
 
 std::vector<UUID> IAccessStorage::tryRemove(const std::vector<UUID> & ids)
 {
-    return applyToMultipleEntities</* ignore_errors = */ true>(
-        ids,
-        [this](const UUID & id) { removeImpl(id); return id; });
+    std::vector<UUID> removed_ids;
+    for (const auto & id : ids)
+    {
+        auto func = [&] { removeImpl(id); };
+        if (tryCall(func))
+            removed_ids.push_back(id);
+    }
+    return removed_ids;
 }
 
 
@@ -316,25 +336,39 @@ void IAccessStorage::update(const UUID & id, const UpdateFunc & update_func)
 
 void IAccessStorage::update(const std::vector<UUID> & ids, const UpdateFunc & update_func)
 {
-    applyToMultipleEntities</* ignore_errors = */ false>(
-        ids,
-        [this, &update_func](const UUID & id) { updateImpl(id, update_func); },
-        "Couldn't update {failed_names}. Successfully updated: {succeeded_names}",
-        [this](const UUID & id) { return outputTypeAndNameOrID(*this, id); });
+    ErrorsTracker tracker(ids.size());
+
+    for (const auto & id : ids)
+    {
+        auto func = [&] { updateImpl(id, update_func); };
+        tracker.tryCall(func);
+    }
+
+    if (tracker.errors())
+    {
+        auto get_name_function = [&](size_t i) { return outputTypeAndNameOrID(*this, ids[i]); };
+        tracker.showErrors("Couldn't update {failed_names}. Successfully updated: {succeeded_names}", get_name_function);
+    }
 }
 
 
 bool IAccessStorage::tryUpdate(const UUID & id, const UpdateFunc & update_func)
 {
-    return doTry([&] { updateImpl(id, update_func); return true; });
+    auto func = [&] { updateImpl(id, update_func); };
+    return tryCall(func);
 }
 
 
 std::vector<UUID> IAccessStorage::tryUpdate(const std::vector<UUID> & ids, const UpdateFunc & update_func)
 {
-    return applyToMultipleEntities</* ignore_errors = */ true>(
-        ids,
-        [this, &update_func](const UUID & id) { updateImpl(id, update_func); return id; });
+    std::vector<UUID> updated_ids;
+    for (const auto & id : ids)
+    {
+        auto func = [&] { updateImpl(id, update_func); };
+        if (tryCall(func))
+            updated_ids.push_back(id);
+    }
+    return updated_ids;
 }
 
 
diff --git a/tests/queries/0_stateless/01292_create_user.reference b/tests/queries/0_stateless/01292_create_user.reference
index 922ee54bef4..775bbaa6a26 100644
--- a/tests/queries/0_stateless/01292_create_user.reference
+++ b/tests/queries/0_stateless/01292_create_user.reference
@@ -81,6 +81,15 @@ CREATE USER u6_01292 DEFAULT ROLE NONE
 -- complex
 CREATE USER u1_01292 IDENTIFIED WITH plaintext_password HOST LOCAL SETTINGS readonly = 1
 CREATE USER u1_01292 HOST LIKE \'%.%.myhost.com\' DEFAULT ROLE NONE SETTINGS PROFILE default
+-- if not exists
+CREATE USER u1_01292
+GRANT r1_01292 TO u1_01292
+-- if not exists-part2
+CREATE USER u1_01292
+GRANT r1_01292, r2_01292 TO u1_01292
+-- or replace
+CREATE USER u1_01292
+CREATE USER u2_01292
 -- multiple users in one command
 CREATE USER u1_01292 DEFAULT ROLE NONE
 CREATE USER u2_01292 DEFAULT ROLE NONE
diff --git a/tests/queries/0_stateless/01292_create_user.sql b/tests/queries/0_stateless/01292_create_user.sql
index 5ae7f3921e6..c8d408147e9 100644
--- a/tests/queries/0_stateless/01292_create_user.sql
+++ b/tests/queries/0_stateless/01292_create_user.sql
@@ -177,6 +177,24 @@ ALTER USER u1_01292 NOT IDENTIFIED HOST LIKE '%.%.myhost.com' DEFAULT ROLE NONE
 SHOW CREATE USER u1_01292;
 DROP USER u1_01292;
 
+SELECT '-- if not exists';
+CREATE USER u1_01292;
+GRANT r1_01292 TO u1_01292;
+SHOW CREATE USER u1_01292;
+SHOW GRANTS FOR u1_01292;
+SELECT '-- if not exists-part2';
+CREATE USER IF NOT EXISTS u1_01292;
+GRANT r2_01292 TO u1_01292;
+SHOW CREATE USER u1_01292;
+SHOW GRANTS FOR u1_01292;
+SELECT '-- or replace';
+CREATE USER OR REPLACE u1_01292;
+SHOW CREATE USER u1_01292;
+SHOW GRANTS FOR u1_01292;
+CREATE USER IF NOT EXISTS u2_01292;
+SHOW CREATE USER u2_01292;
+DROP USER u1_01292, u2_01292;
+
 SELECT '-- multiple users in one command';
 CREATE USER u1_01292, u2_01292 DEFAULT ROLE NONE;
 CREATE USER u3_01292, u4_01292 HOST LIKE '%.%.myhost.com';

From 72f403bb147b4823490693564412ae98a86f7a34 Mon Sep 17 00:00:00 2001
From: Vitaliy Zakaznikov <vzakaznikov@protonmail.com>
Date: Fri, 24 Jul 2020 10:05:13 -0400
Subject: [PATCH 02/25] Increasing shell default timeout to 120 sec.

---
 tests/testflows/helpers/cluster.py | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tests/testflows/helpers/cluster.py b/tests/testflows/helpers/cluster.py
index 9f86d44124c..6d3ae97e000 100644
--- a/tests/testflows/helpers/cluster.py
+++ b/tests/testflows/helpers/cluster.py
@@ -167,17 +167,20 @@ class Cluster(object):
         self.docker_compose += f" --project-directory \"{docker_compose_project_dir}\" --file \"{docker_compose_file_path}\""
         self.lock = threading.Lock()
 
-    def shell(self, node):
+    def shell(self, node, timeout=120):
         """Returns unique shell terminal to be used.
         """
         if node is None:
             return Shell()
 
-        return Shell(command=[
+        shell = Shell(command=[
                 "/bin/bash", "--noediting", "-c", f"{self.docker_compose} exec {node} bash --noediting"
             ], name=node)
 
-    def bash(self, node, timeout=60):
+        shell.timeout = timeout
+        return shell
+
+    def bash(self, node, timeout=120):
         """Returns thread-local bash terminal
         to a specific node.
 

From 67d4529783b602d8a3eabd7f0efef7b03ad06497 Mon Sep 17 00:00:00 2001
From: Ivan Babrou <ivan@cloudflare.com>
Date: Fri, 24 Jul 2020 14:48:16 -0700
Subject: [PATCH 03/25] Show total granules examined by skipping indices

This change makes skipping index efficiency more obvious, changing this:

```
Index `idx_duration` has dropped 59 granules.
```

Into this:

```
Index `idx_duration` has dropped 59 / 61 granules.
```
---
 src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp b/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp
index 306bcd9000a..e70d2d3743a 100644
--- a/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp
+++ b/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp
@@ -1516,6 +1516,7 @@ MarkRanges MergeTreeDataSelectExecutor::filterMarksUsingIndex(
         part->index_granularity_info.index_granularity_bytes);
 
     size_t granules_dropped = 0;
+    size_t total_granules = 0;
 
     size_t marks_count = part->getMarksCount();
     size_t final_mark = part->index_granularity.hasFinalMark();
@@ -1542,6 +1543,8 @@ MarkRanges MergeTreeDataSelectExecutor::filterMarksUsingIndex(
         if (last_index_mark != index_range.begin || !granule)
             reader.seek(index_range.begin);
 
+        total_granules += index_range.end - index_range.begin;
+
         for (size_t index_mark = index_range.begin; index_mark < index_range.end; ++index_mark)
         {
             if (index_mark != index_range.begin || !granule || last_index_mark != index_range.begin)
@@ -1566,7 +1569,7 @@ MarkRanges MergeTreeDataSelectExecutor::filterMarksUsingIndex(
         last_index_mark = index_range.end - 1;
     }
 
-    LOG_DEBUG(log, "Index {} has dropped {} granules.", backQuote(index_helper->index.name), granules_dropped);
+    LOG_DEBUG(log, "Index {} has dropped {} / {} granules.", backQuote(index_helper->index.name), granules_dropped, total_granules);
 
     return res;
 }

From 78d357f0d2c53305dd40306d2a264d3f54f48cd0 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Sat, 25 Jul 2020 17:42:20 +0300
Subject: [PATCH 04/25] Add a test for sticking mutations bug

---
 src/Storages/MergeTree/IMergeTreeDataPart.cpp | 23 +++++++++
 .../MergeTree/MergeTreeDataPartWide.cpp       | 13 +++++
 .../01415_sticking_mutations.reference        |  1 +
 .../0_stateless/01415_sticking_mutations.sh   | 47 +++++++++++++++++++
 4 files changed, 84 insertions(+)
 create mode 100644 tests/queries/0_stateless/01415_sticking_mutations.reference
 create mode 100755 tests/queries/0_stateless/01415_sticking_mutations.sh

diff --git a/src/Storages/MergeTree/IMergeTreeDataPart.cpp b/src/Storages/MergeTree/IMergeTreeDataPart.cpp
index 1d04118643f..0c329299209 100644
--- a/src/Storages/MergeTree/IMergeTreeDataPart.cpp
+++ b/src/Storages/MergeTree/IMergeTreeDataPart.cpp
@@ -552,6 +552,29 @@ void IMergeTreeDataPart::loadRowsCount()
         auto buf = openForReading(volume->getDisk(), path);
         readIntText(rows_count, *buf);
         assertEOF(*buf);
+
+#ifndef NDEBUG
+        /// columns have to be loaded
+        for (const auto & column : getColumns())
+        {
+            if (column.type->isValueRepresentedByNumber())
+            {
+                auto size = getColumnSize(column.name, *column.type);
+
+                if (size.data_uncompressed == 0)
+                    continue;
+
+                size_t rows_in_column = size.data_uncompressed / column.type->getSizeOfValueInMemory();
+                if (rows_in_column != rows_count)
+                {
+                    throw Exception(
+                        ErrorCodes::LOGICAL_ERROR,
+                        "Column {} has rows count {} according to size in memory "
+                        "and size of single value, but data part {} has {} rows", backQuote(column.name), rows_in_column, name, rows_count);
+                }
+            }
+        }
+#endif
     }
     else
     {
diff --git a/src/Storages/MergeTree/MergeTreeDataPartWide.cpp b/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
index b33a3d4645d..fb6784434a8 100644
--- a/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
+++ b/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
@@ -237,7 +237,20 @@ void MergeTreeDataPartWide::calculateEachColumnSizes(ColumnSizeByName & each_col
         ColumnSize size = getColumnSizeImpl(column.name, *column.type, &processed_substreams);
         each_columns_size[column.name] = size;
         total_size.add(size);
+
+#ifndef NDEBUG
+        if (rows_count != 0 && column.type->isValueRepresentedByNumber())
+        {
+            size_t rows_in_column = size.data_uncompressed / column.type->getSizeOfValueInMemory();
+            if (rows_in_column != rows_count)
+            {
+                throw Exception(
+                    ErrorCodes::LOGICAL_ERROR,
+                    "Column {} has rows count {} according to size in memory and size of single value, but data part {} has {} rows", backQuote(column.name), rows_in_column, name, rows_count);
+            }
+        }
     }
+#endif
 }
 
 }
diff --git a/tests/queries/0_stateless/01415_sticking_mutations.reference b/tests/queries/0_stateless/01415_sticking_mutations.reference
new file mode 100644
index 00000000000..d00491fd7e5
--- /dev/null
+++ b/tests/queries/0_stateless/01415_sticking_mutations.reference
@@ -0,0 +1 @@
+1
diff --git a/tests/queries/0_stateless/01415_sticking_mutations.sh b/tests/queries/0_stateless/01415_sticking_mutations.sh
new file mode 100755
index 00000000000..fdc9b580274
--- /dev/null
+++ b/tests/queries/0_stateless/01415_sticking_mutations.sh
@@ -0,0 +1,47 @@
+#!/usr/bin/env bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+. $CURDIR/../shell_config.sh
+
+$CLICKHOUSE_CLIENT --query "DROP TABLE IF EXISTS sticking_mutations"
+
+$CLICKHOUSE_CLIENT -n --query "CREATE TABLE sticking_mutations (
+  key UInt64,
+  value1 String,
+  value2 UInt8
+)
+ENGINE = MergeTree()
+ORDER BY key;"
+
+$CLICKHOUSE_CLIENT --query "INSERT INTO sticking_mutations SELECT number, toString(number), number % 128 FROM numbers(1000)"
+
+# if merges stopped for normal merge tree mutations will stick
+$CLICKHOUSE_CLIENT --query "SYSTEM STOP MERGES sticking_mutations"
+
+$CLICKHOUSE_CLIENT --query "ALTER TABLE sticking_mutations DELETE WHERE value2 % 32 == 0, MODIFY COLUMN value1 UInt64;" &
+
+
+##### wait mutation to start #####
+check_query="SELECT count() FROM system.mutations WHERE table='sticking_mutations' and database='$CLICKHOUSE_DATABASE'"
+
+query_result=`$CLICKHOUSE_CLIENT --query="$check_query" 2>&1`
+
+while [ "$query_result" == "0" ]
+do
+    query_result=`$CLICKHOUSE_CLIENT --query="$check_query" 2>&1`
+    sleep 0.5
+done
+##### wait mutation to start #####
+
+# Starting merges to execute sticked mutations
+
+$CLICKHOUSE_CLIENT --query "SYSTEM START MERGES sticking_mutations"
+
+# just to be sure, that previous mutations finished
+$CLICKHOUSE_CLIENT --query "ALTER TABLE sticking_mutations DELETE WHERE value % 31 == 0 SETTINGS mutations_sync = 1"
+
+$CLICKHOUSE_CLIENT --query "OPTIMIZE TABLE sticking_mutations FINAL"
+
+$CLICKHOUSE_CLIENT --query "SELECT 1"
+
+$CLICKHOUSE_CLIENT --query "DROP TABLE IF EXISTS sticking_mutations"

From 393a9195caac261f2a74da712a12a1eb74b182e5 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Sat, 25 Jul 2020 17:45:46 +0300
Subject: [PATCH 05/25] Better exception message

---
 src/Storages/MergeTree/MergeTreeDataPartWide.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Storages/MergeTree/MergeTreeDataPartWide.cpp b/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
index fb6784434a8..b9454fcf818 100644
--- a/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
+++ b/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
@@ -246,7 +246,8 @@ void MergeTreeDataPartWide::calculateEachColumnSizes(ColumnSizeByName & each_col
             {
                 throw Exception(
                     ErrorCodes::LOGICAL_ERROR,
-                    "Column {} has rows count {} according to size in memory and size of single value, but data part {} has {} rows", backQuote(column.name), rows_in_column, name, rows_count);
+                    "Column {} has rows count {} according to size in memory "
+                    "and size of single value, but data part {} has {} rows", backQuote(column.name), rows_in_column, name, rows_count);
             }
         }
     }

From eae7dc852ea2bfcd223c2ce3981b2687ed0ff987 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Sat, 25 Jul 2020 23:54:33 +0300
Subject: [PATCH 06/25] Fix build

---
 src/Storages/MergeTree/MergeTreeDataPartWide.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Storages/MergeTree/MergeTreeDataPartWide.cpp b/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
index b9454fcf818..131f875e9f8 100644
--- a/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
+++ b/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
@@ -250,8 +250,8 @@ void MergeTreeDataPartWide::calculateEachColumnSizes(ColumnSizeByName & each_col
                     "and size of single value, but data part {} has {} rows", backQuote(column.name), rows_in_column, name, rows_count);
             }
         }
-    }
 #endif
+    }
 }
 
 }

From c66dc23a47106003748b306b6a5601f84def4f5e Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Sat, 25 Jul 2020 23:56:29 +0300
Subject: [PATCH 07/25] Fix error style

---
 src/Storages/MergeTree/MergeTreeDataPartWide.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/Storages/MergeTree/MergeTreeDataPartWide.cpp b/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
index 131f875e9f8..a3e45a22d92 100644
--- a/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
+++ b/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
@@ -13,6 +13,7 @@ namespace ErrorCodes
     extern const int CANNOT_READ_ALL_DATA;
     extern const int NO_FILE_IN_DATA_PART;
     extern const int BAD_SIZE_OF_FILE_IN_DATA_PART;
+    extern const int LOGICAL_ERROR;
 }
 
 

From e0bf5913e77e0360661fb400ee7333b92eaec375 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Sun, 26 Jul 2020 17:21:57 +0300
Subject: [PATCH 08/25] Fix sticking mutations

---
 src/Interpreters/ExpressionActions.cpp        |  2 +-
 src/Interpreters/ExpressionActions.h          |  2 +-
 src/Interpreters/MutationsInterpreter.cpp     | 19 +++++
 src/Interpreters/MutationsInterpreter.h       |  8 +-
 .../MergeTree/MergeTreeDataMergerMutator.cpp  |  2 +-
 .../01415_sticking_mutations.reference        | 13 ++++
 .../0_stateless/01415_sticking_mutations.sh   | 77 ++++++++++++-------
 7 files changed, 91 insertions(+), 32 deletions(-)

diff --git a/src/Interpreters/ExpressionActions.cpp b/src/Interpreters/ExpressionActions.cpp
index 32e3000a65d..0e1d0c51704 100644
--- a/src/Interpreters/ExpressionActions.cpp
+++ b/src/Interpreters/ExpressionActions.cpp
@@ -1309,7 +1309,7 @@ void ExpressionActionsChain::finalize()
     }
 }
 
-std::string ExpressionActionsChain::dumpChain()
+std::string ExpressionActionsChain::dumpChain() const
 {
     std::stringstream ss;
 
diff --git a/src/Interpreters/ExpressionActions.h b/src/Interpreters/ExpressionActions.h
index 1aae3f5e021..49da9a5f810 100644
--- a/src/Interpreters/ExpressionActions.h
+++ b/src/Interpreters/ExpressionActions.h
@@ -347,7 +347,7 @@ struct ExpressionActionsChain
         return steps.back();
     }
 
-    std::string dumpChain();
+    std::string dumpChain() const;
 };
 
 }
diff --git a/src/Interpreters/MutationsInterpreter.cpp b/src/Interpreters/MutationsInterpreter.cpp
index 94740ae0bd4..bb83001852c 100644
--- a/src/Interpreters/MutationsInterpreter.cpp
+++ b/src/Interpreters/MutationsInterpreter.cpp
@@ -764,4 +764,23 @@ std::optional<SortDescription> MutationsInterpreter::getStorageSortDescriptionIf
     return sort_description;
 }
 
+bool MutationsInterpreter::Stage::isAffectingAllColumns(const Names & storage_columns) const
+{
+    /// is subset
+    for (const auto & storage_column : storage_columns)
+        if (!output_columns.contains(storage_column))
+            return false;
+
+    return true;
+}
+
+bool MutationsInterpreter::isAffectingAllColumns() const
+{
+    auto storage_columns = metadata_snapshot->getColumns().getNamesOfPhysical();
+    for (const auto & stage : stages)
+        if (stage.isAffectingAllColumns(storage_columns))
+            return true;
+    return false;
+}
+
 }
diff --git a/src/Interpreters/MutationsInterpreter.h b/src/Interpreters/MutationsInterpreter.h
index 894d135a099..4ba96533210 100644
--- a/src/Interpreters/MutationsInterpreter.h
+++ b/src/Interpreters/MutationsInterpreter.h
@@ -42,6 +42,8 @@ public:
     /// Only changed columns.
     const Block & getUpdatedHeader() const;
 
+    bool isAffectingAllColumns() const;
+
 private:
     ASTPtr prepare(bool dry_run);
 
@@ -86,8 +88,8 @@ private:
         ASTs filters;
         std::unordered_map<String, ASTPtr> column_to_updated;
 
-        /// Contains columns that are changed by this stage,
-        /// columns changed by the previous stages and also columns needed by the next stages.
+        /// Contains columns that are changed by this stage, columns changed by
+        /// the previous stages and also columns needed by the next stages.
         NameSet output_columns;
 
         std::unique_ptr<ExpressionAnalyzer> analyzer;
@@ -97,6 +99,8 @@ private:
         /// then there is (possibly) an UPDATE step, and finally a projection step.
         ExpressionActionsChain expressions_chain;
         Names filter_column_names;
+
+        bool isAffectingAllColumns(const Names & storage_columns) const;
     };
 
     std::unique_ptr<Block> updated_header;
diff --git a/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp b/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
index b59070ca070..cd14a35edba 100644
--- a/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
+++ b/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
@@ -1092,7 +1092,7 @@ MergeTreeData::MutableDataPartPtr MergeTreeDataMergerMutator::mutatePartToTempor
         need_remove_expired_values = true;
 
     /// All columns from part are changed and may be some more that were missing before in part
-    if (!isWidePart(source_part) || source_part->getColumns().isSubsetOf(updated_header.getNamesAndTypesList()))
+    if (!isWidePart(source_part) || (interpreter && interpreter->isAffectingAllColumns()))
     {
         auto part_indices = getIndicesForNewDataPart(metadata_snapshot->getSecondaryIndices(), for_file_renames);
         mutateAllPartColumns(
diff --git a/tests/queries/0_stateless/01415_sticking_mutations.reference b/tests/queries/0_stateless/01415_sticking_mutations.reference
index d00491fd7e5..5d2e2b67958 100644
--- a/tests/queries/0_stateless/01415_sticking_mutations.reference
+++ b/tests/queries/0_stateless/01415_sticking_mutations.reference
@@ -1 +1,14 @@
 1
+CREATE TABLE default.sticking_mutations\n(\n    `date` Date,\n    `key` UInt64,\n    `value1` UInt64,\n    `value2` UInt8\n)\nENGINE = MergeTree()\nORDER BY key\nSETTINGS index_granularity = 8192
+1
+CREATE TABLE default.sticking_mutations\n(\n    `date` Date,\n    `key` UInt64,\n    `value1` UInt64,\n    `value2` UInt8\n)\nENGINE = MergeTree()\nORDER BY key\nSETTINGS index_granularity = 8192
+1
+CREATE TABLE default.sticking_mutations\n(\n    `date` Date,\n    `key` UInt64,\n    `value1` String,\n    `value2` UInt8\n)\nENGINE = MergeTree()\nORDER BY key\nSETTINGS index_granularity = 8192
+1
+CREATE TABLE default.sticking_mutations\n(\n    `date` Date,\n    `key` UInt64,\n    `value1` String,\n    `value2` UInt8\n)\nENGINE = MergeTree()\nORDER BY key\nSETTINGS index_granularity = 8192
+1
+CREATE TABLE default.sticking_mutations\n(\n    `date` Date,\n    `key` UInt64,\n    `value2` UInt8\n)\nENGINE = MergeTree()\nORDER BY key\nSETTINGS index_granularity = 8192
+1
+CREATE TABLE default.sticking_mutations\n(\n    `date` Date,\n    `key` UInt64,\n    `renamed_value1` String,\n    `value2` UInt8\n)\nENGINE = MergeTree()\nORDER BY key\nSETTINGS index_granularity = 8192
+1
+CREATE TABLE default.sticking_mutations\n(\n    `date` Date,\n    `key` UInt64,\n    `value1` UInt64,\n    `value2` UInt8\n)\nENGINE = MergeTree()\nORDER BY key\nTTL date + toIntervalDay(1)\nSETTINGS index_granularity = 8192
diff --git a/tests/queries/0_stateless/01415_sticking_mutations.sh b/tests/queries/0_stateless/01415_sticking_mutations.sh
index fdc9b580274..04846be06d6 100755
--- a/tests/queries/0_stateless/01415_sticking_mutations.sh
+++ b/tests/queries/0_stateless/01415_sticking_mutations.sh
@@ -1,47 +1,70 @@
 #!/usr/bin/env bash
 
+set -e
+
 CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
 . $CURDIR/../shell_config.sh
 
 $CLICKHOUSE_CLIENT --query "DROP TABLE IF EXISTS sticking_mutations"
 
-$CLICKHOUSE_CLIENT -n --query "CREATE TABLE sticking_mutations (
-  key UInt64,
-  value1 String,
-  value2 UInt8
-)
-ENGINE = MergeTree()
-ORDER BY key;"
+function check_sticky_mutations()
+{
+    $CLICKHOUSE_CLIENT -n --query "CREATE TABLE sticking_mutations (
+      date Date,
+      key UInt64,
+      value1 String,
+      value2 UInt8
+    )
+    ENGINE = MergeTree()
+    ORDER BY key;"
 
-$CLICKHOUSE_CLIENT --query "INSERT INTO sticking_mutations SELECT number, toString(number), number % 128 FROM numbers(1000)"
+    $CLICKHOUSE_CLIENT --query "INSERT INTO sticking_mutations SELECT toDate('2020-07-10'), number, toString(number), number % 128 FROM numbers(1000)"
 
-# if merges stopped for normal merge tree mutations will stick
-$CLICKHOUSE_CLIENT --query "SYSTEM STOP MERGES sticking_mutations"
+    $CLICKHOUSE_CLIENT --query "INSERT INTO sticking_mutations SELECT toDate('2100-01-10'), number, toString(number), number % 128 FROM numbers(1000)"
 
-$CLICKHOUSE_CLIENT --query "ALTER TABLE sticking_mutations DELETE WHERE value2 % 32 == 0, MODIFY COLUMN value1 UInt64;" &
+    # if merges stopped for normal merge tree mutations will stick
+    $CLICKHOUSE_CLIENT --query "SYSTEM STOP MERGES sticking_mutations"
 
+    $CLICKHOUSE_CLIENT --query "$1" &
 
-##### wait mutation to start #####
-check_query="SELECT count() FROM system.mutations WHERE table='sticking_mutations' and database='$CLICKHOUSE_DATABASE'"
+    ##### wait mutation to start #####
+    check_query="SELECT count() FROM system.mutations WHERE table='sticking_mutations' and database='$CLICKHOUSE_DATABASE' and is_done = 0"
 
-query_result=`$CLICKHOUSE_CLIENT --query="$check_query" 2>&1`
-
-while [ "$query_result" == "0" ]
-do
     query_result=`$CLICKHOUSE_CLIENT --query="$check_query" 2>&1`
-    sleep 0.5
-done
-##### wait mutation to start #####
 
-# Starting merges to execute sticked mutations
+    while [ "$query_result" == "0" ]
+    do
+        query_result=`$CLICKHOUSE_CLIENT --query="$check_query" 2>&1`
+        sleep 0.5
+    done
+    ##### wait mutation to start #####
 
-$CLICKHOUSE_CLIENT --query "SYSTEM START MERGES sticking_mutations"
+    # Starting merges to execute sticked mutations
 
-# just to be sure, that previous mutations finished
-$CLICKHOUSE_CLIENT --query "ALTER TABLE sticking_mutations DELETE WHERE value % 31 == 0 SETTINGS mutations_sync = 1"
+    $CLICKHOUSE_CLIENT --query "SYSTEM START MERGES sticking_mutations"
 
-$CLICKHOUSE_CLIENT --query "OPTIMIZE TABLE sticking_mutations FINAL"
+    # just to be sure, that previous mutations finished
+    $CLICKHOUSE_CLIENT --query "ALTER TABLE sticking_mutations DELETE WHERE value2 % 31 == 0 SETTINGS mutations_sync = 1"
 
-$CLICKHOUSE_CLIENT --query "SELECT 1"
+    $CLICKHOUSE_CLIENT --query "OPTIMIZE TABLE sticking_mutations FINAL"
 
-$CLICKHOUSE_CLIENT --query "DROP TABLE IF EXISTS sticking_mutations"
+    $CLICKHOUSE_CLIENT --query "SELECT sum(cityHash64(*)) > 1 FROM sticking_mutations WHERE key > 10"
+
+    $CLICKHOUSE_CLIENT --query "SHOW CREATE TABLE sticking_mutations"
+
+    $CLICKHOUSE_CLIENT --query "DROP TABLE IF EXISTS sticking_mutations"
+}
+
+check_sticky_mutations "ALTER TABLE sticking_mutations DELETE WHERE value2 % 32 == 0, MODIFY COLUMN value1 UInt64"
+
+check_sticky_mutations "ALTER TABLE sticking_mutations MODIFY COLUMN value1 UInt64, DELETE WHERE value2 % 32 == 0"
+
+check_sticky_mutations "ALTER TABLE sticking_mutations UPDATE value1 = 15 WHERE key < 2000, DELETE WHERE value2 % 32 == 0"
+
+check_sticky_mutations "ALTER TABLE sticking_mutations DELETE WHERE value2 % 32 == 0, UPDATE value1 = 15 WHERE key < 2000"
+
+check_sticky_mutations "ALTER TABLE sticking_mutations DELETE WHERE value2 % 32 == 0, DROP COLUMN value1"
+
+check_sticky_mutations "ALTER TABLE sticking_mutations DELETE WHERE value2 % 32 == 0, RENAME COLUMN value1 TO renamed_value1"
+
+check_sticky_mutations "ALTER TABLE sticking_mutations MODIFY COLUMN value1 UInt64, MODIFY TTL date + INTERVAL 1 DAY"

From 561906d5f47b50cae130c2fa33403272af17da55 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Sun, 26 Jul 2020 17:27:31 +0300
Subject: [PATCH 09/25] Better comments

---
 src/Interpreters/MutationsInterpreter.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Interpreters/MutationsInterpreter.h b/src/Interpreters/MutationsInterpreter.h
index 4ba96533210..8d189b121ee 100644
--- a/src/Interpreters/MutationsInterpreter.h
+++ b/src/Interpreters/MutationsInterpreter.h
@@ -42,6 +42,7 @@ public:
     /// Only changed columns.
     const Block & getUpdatedHeader() const;
 
+    /// At least one mutation stage affects all columns in storage
     bool isAffectingAllColumns() const;
 
 private:
@@ -100,6 +101,7 @@ private:
         ExpressionActionsChain expressions_chain;
         Names filter_column_names;
 
+        /// Check that stage affects all storage columns
         bool isAffectingAllColumns(const Names & storage_columns) const;
     };
 

From 2d8e36ed5fd02ee3d8e464f51d10bec6d0eecfe2 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Sun, 26 Jul 2020 18:58:03 +0300
Subject: [PATCH 10/25] Add test for sticking mutations

---
 .../test_mutations_hardlinks/__init__.py      |   0
 .../test_mutations_hardlinks/test.py          | 133 ++++++++++++++++++
 2 files changed, 133 insertions(+)
 create mode 100644 tests/integration/test_mutations_hardlinks/__init__.py
 create mode 100644 tests/integration/test_mutations_hardlinks/test.py

diff --git a/tests/integration/test_mutations_hardlinks/__init__.py b/tests/integration/test_mutations_hardlinks/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/integration/test_mutations_hardlinks/test.py b/tests/integration/test_mutations_hardlinks/test.py
new file mode 100644
index 00000000000..56852f572ff
--- /dev/null
+++ b/tests/integration/test_mutations_hardlinks/test.py
@@ -0,0 +1,133 @@
+import pytest
+
+import os
+import time
+from helpers.cluster import ClickHouseCluster
+from helpers.test_tools import assert_eq_with_retry
+from multiprocessing.dummy import Pool
+
+
+cluster = ClickHouseCluster(__file__)
+
+node1 = cluster.add_instance('node1')
+
+@pytest.fixture(scope="module")
+def started_cluster():
+    try:
+        cluster.start()
+        yield cluster
+    finally:
+        cluster.shutdown()
+
+
+def check_hardlinks(table, part_path, column_file, count):
+    column_path = os.path.join("/var/lib/clickhouse/data/default", table, part_path, column_file)
+    script = """
+        export INODE=`ls -i {column_path} | awk '{{print $1}}'`
+        export COUNT=`find /var/lib/clickhouse -inum $INODE | wc -l`
+        test $COUNT = {count}
+    """.format(column_path=column_path, count=count)
+
+    node1.exec_in_container(["bash", "-c", script])
+
+
+def check_exists(table, part_path, column_file):
+    column_path = os.path.join("/var/lib/clickhouse/data/default", table, part_path, column_file)
+
+    node1.exec_in_container(["bash", "-c", "test -f {}".format(column_path)])
+
+
+def test_update_mutation(started_cluster):
+    node1.query("CREATE TABLE table_for_update(key UInt64, value1 UInt64, value2 String) ENGINE MergeTree() ORDER BY tuple()")
+
+    node1.query("INSERT INTO table_for_update SELECT number, number, toString(number) from numbers(100)")
+
+    assert int(node1.query("SELECT sum(value1) FROM table_for_update").strip()) == sum(range(100))
+
+    node1.query("ALTER TABLE table_for_update UPDATE value1 = value1 * value1 WHERE 1", settings={"mutations_sync" : "2"})
+    assert int(node1.query("SELECT sum(value1) FROM table_for_update").strip()) == sum(i * i for i in range(100))
+
+    check_hardlinks("table_for_update", "all_1_1_0_2", "key.bin", 2)
+    check_hardlinks("table_for_update", "all_1_1_0_2", "value2.bin", 2)
+    check_hardlinks("table_for_update", "all_1_1_0_2", "value1.bin", 1)
+
+    node1.query("ALTER TABLE table_for_update UPDATE key=key, value1=value1, value2=value2 WHERE 1", settings={"mutations_sync": "2"})
+
+    assert int(node1.query("SELECT sum(value1) FROM table_for_update").strip()) == sum(i * i for i in range(100))
+
+    check_hardlinks("table_for_update", "all_1_1_0_3", "key.bin", 1)
+    check_hardlinks("table_for_update", "all_1_1_0_3", "value1.bin", 1)
+    check_hardlinks("table_for_update", "all_1_1_0_3", "value2.bin", 1)
+
+
+def test_modify_mutation(started_cluster):
+    node1.query("CREATE TABLE table_for_modify(key UInt64, value1 UInt64, value2 String) ENGINE MergeTree() ORDER BY tuple()")
+
+    node1.query("INSERT INTO table_for_modify SELECT number, number, toString(number) from numbers(100)")
+
+    assert int(node1.query("SELECT sum(value1) FROM table_for_modify").strip()) == sum(range(100))
+
+    node1.query("ALTER TABLE table_for_modify MODIFY COLUMN value2 UInt64", settings={"mutations_sync" : "2"})
+
+    assert int(node1.query("SELECT sum(value2) FROM table_for_modify").strip()) == sum(range(100))
+
+    check_hardlinks("table_for_modify", "all_1_1_0_2", "key.bin", 2)
+    check_hardlinks("table_for_modify", "all_1_1_0_2", "value1.bin", 2)
+    check_hardlinks("table_for_modify", "all_1_1_0_2", "value2.bin", 1)
+
+
+def test_drop_mutation(started_cluster):
+    node1.query("CREATE TABLE table_for_drop(key UInt64, value1 UInt64, value2 String) ENGINE MergeTree() ORDER BY tuple()")
+
+    node1.query("INSERT INTO table_for_drop SELECT number, number, toString(number) from numbers(100)")
+
+    assert int(node1.query("SELECT sum(value1) FROM table_for_drop").strip()) == sum(range(100))
+
+    node1.query("ALTER TABLE table_for_drop DROP COLUMN value2", settings={"mutations_sync": "2"})
+
+    check_hardlinks("table_for_drop", "all_1_1_0_2", "key.bin", 2)
+    check_hardlinks("table_for_drop", "all_1_1_0_2", "value1.bin", 2)
+
+    with pytest.raises(Exception):
+        check_exists("table_for_drop", "all_1_1_0_2", "value2.bin")
+    with pytest.raises(Exception):
+        check_exists("table_for_drop", "all_1_1_0_2", "value2.mrk")
+
+
+def test_delete_and_drop_mutation(started_cluster):
+    node1.query("CREATE TABLE table_for_delete_and_drop(key UInt64, value1 UInt64, value2 String) ENGINE MergeTree() ORDER BY tuple()")
+
+    node1.query("INSERT INTO table_for_delete_and_drop SELECT number, number, toString(number) from numbers(100)")
+
+    assert int(node1.query("SELECT sum(value1) FROM table_for_delete_and_drop").strip()) == sum(range(100))
+
+    node1.query("SYSTEM STOP MERGES")
+
+    def mutate():
+        node1.query("ALTER TABLE table_for_delete_and_drop DELETE WHERE key % 2 == 0, DROP COLUMN value2")
+
+    p = Pool(2)
+    p.apply_async(mutate)
+
+    for _ in range(1, 100):
+        result = node1.query("SELECT COUNT() FROM system.mutations WHERE table = 'table_for_delete_and_drop' and is_done=0")
+        try:
+            if int(result.strip()) == 2:
+                break
+        except:
+            print "Result", result
+            pass
+
+        time.sleep(0.5)
+
+    node1.query("SYSTEM START MERGES")
+
+    assert_eq_with_retry(node1, "SELECT COUNT() FROM table_for_delete_and_drop", str(sum(1 for i in range(100) if i % 2 != 0)))
+
+    check_hardlinks("table_for_delete_and_drop", "all_1_1_0_3", "key.bin", 1)
+    check_hardlinks("table_for_delete_and_drop", "all_1_1_0_3", "value1.bin", 1)
+
+    with pytest.raises(Exception):
+        check_exists("table_for_delete_and_drop", "all_1_1_0_3", "value2.bin")
+    with pytest.raises(Exception):
+        check_exists("table_for_delete_and_drop", "all_1_1_0_3", "value2.mrk")

From 1707f84a44ce010710aefa097684c8e85bf6d35b Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Mon, 27 Jul 2020 12:42:37 +0300
Subject: [PATCH 11/25] Less strict check and rare rename bug

---
 src/Interpreters/MutationsInterpreter.cpp     |  8 +--
 src/Interpreters/MutationsInterpreter.h       |  2 +-
 src/Storages/MergeTree/IMergeTreeDataPart.cpp |  3 +-
 .../MergeTree/MergeTreeDataMergerMutator.cpp  | 55 +++++++++++++++----
 .../MergeTree/MergeTreeDataPartWide.cpp       |  3 +-
 5 files changed, 53 insertions(+), 18 deletions(-)

diff --git a/src/Interpreters/MutationsInterpreter.cpp b/src/Interpreters/MutationsInterpreter.cpp
index bb83001852c..e502f517ad8 100644
--- a/src/Interpreters/MutationsInterpreter.cpp
+++ b/src/Interpreters/MutationsInterpreter.cpp
@@ -777,10 +777,10 @@ bool MutationsInterpreter::Stage::isAffectingAllColumns(const Names & storage_co
 bool MutationsInterpreter::isAffectingAllColumns() const
 {
     auto storage_columns = metadata_snapshot->getColumns().getNamesOfPhysical();
-    for (const auto & stage : stages)
-        if (stage.isAffectingAllColumns(storage_columns))
-            return true;
-    return false;
+    if (stages.empty())
+        throw Exception(ErrorCodes::LOGICAL_ERROR, "Mutation interpreter has no stages");
+
+    return stages.back().isAffectingAllColumns(storage_columns);
 }
 
 }
diff --git a/src/Interpreters/MutationsInterpreter.h b/src/Interpreters/MutationsInterpreter.h
index 8d189b121ee..c9130ad6613 100644
--- a/src/Interpreters/MutationsInterpreter.h
+++ b/src/Interpreters/MutationsInterpreter.h
@@ -42,7 +42,7 @@ public:
     /// Only changed columns.
     const Block & getUpdatedHeader() const;
 
-    /// At least one mutation stage affects all columns in storage
+    /// Latest mutation stage affects all columns in storage
     bool isAffectingAllColumns() const;
 
 private:
diff --git a/src/Storages/MergeTree/IMergeTreeDataPart.cpp b/src/Storages/MergeTree/IMergeTreeDataPart.cpp
index 0c329299209..d5b59f3d7b6 100644
--- a/src/Storages/MergeTree/IMergeTreeDataPart.cpp
+++ b/src/Storages/MergeTree/IMergeTreeDataPart.cpp
@@ -557,7 +557,8 @@ void IMergeTreeDataPart::loadRowsCount()
         /// columns have to be loaded
         for (const auto & column : getColumns())
         {
-            if (column.type->isValueRepresentedByNumber())
+            /// Most trivial types
+            if (column.type->isValueRepresentedByNumber() && !column.type->haveSubtypes())
             {
                 auto size = getColumnSize(column.name, *column.type);
 
diff --git a/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp b/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
index cd14a35edba..2b407cb7269 100644
--- a/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
+++ b/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
@@ -1478,13 +1478,14 @@ NamesAndTypesList MergeTreeDataMergerMutator::getColumnsForNewDataPart(
         return updated_header.getNamesAndTypesList();
 
     NameSet removed_columns;
-    NameToNameMap renamed_columns;
+    NameToNameMap renamed_columns_to_from;
+    /// All commands are validated in AlterCommand so we don't care about order
     for (const auto & command : commands_for_removes)
     {
         if (command.type == MutationCommand::DROP_COLUMN)
             removed_columns.insert(command.column_name);
         if (command.type == MutationCommand::RENAME_COLUMN)
-            renamed_columns.emplace(command.rename_to, command.column_name);
+            renamed_columns_to_from.emplace(command.rename_to, command.column_name);
     }
     Names source_column_names = source_part->getColumns().getNames();
     NameSet source_columns_name_set(source_column_names.begin(), source_column_names.end());
@@ -1497,17 +1498,49 @@ NamesAndTypesList MergeTreeDataMergerMutator::getColumnsForNewDataPart(
                 it->type = updated_type;
             ++it;
         }
-        else if (source_columns_name_set.count(it->name) && !removed_columns.count(it->name))
-        {
-            ++it;
-        }
-        else if (renamed_columns.count(it->name) && source_columns_name_set.count(renamed_columns[it->name]))
-        {
-            ++it;
-        }
         else
         {
-            it = storage_columns.erase(it);
+            if (!source_columns_name_set.count(it->name))
+            {
+                /// Source part doesn't have column but some other column
+                /// was renamed to it's name.
+                auto renamed_it = renamed_columns_to_from.find(it->name);
+                if (renamed_it != renamed_columns_to_from.end()
+                    && source_columns_name_set.count(renamed_it->second))
+                    ++it;
+                else
+                    it = storage_columns.erase(it);
+            }
+            else
+            {
+                bool was_renamed = false;
+                bool was_removed = removed_columns.count(it->name);
+
+                /// Check that this column was renamed to some other name
+                for (const auto & [rename_to, rename_from] : renamed_columns_to_from)
+                {
+                    if (rename_from == it->name)
+                    {
+                        was_renamed = true;
+                        break;
+                    }
+                }
+
+                /// If we want to rename this column to some other name, than it
+                /// should it's previous version should be dropped or removed
+                if (renamed_columns_to_from.count(it->name) && !was_renamed && !was_removed)
+                    throw Exception(
+                        ErrorCodes::LOGICAL_ERROR,
+                        "Incorrect mutation commands, trying to rename column {} to {}, but part {} already has column {}", renamed_columns_to_from[it->name], it->name, source_part->name, it->name);
+
+
+                /// Column was renamed and no other column renamed to it's name
+                /// or column is dropped.
+                if (!renamed_columns_to_from.count(it->name) && (was_renamed || was_removed))
+                    it = storage_columns.erase(it);
+                else
+                    ++it;
+            }
         }
     }
 
diff --git a/src/Storages/MergeTree/MergeTreeDataPartWide.cpp b/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
index a3e45a22d92..f133d438866 100644
--- a/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
+++ b/src/Storages/MergeTree/MergeTreeDataPartWide.cpp
@@ -240,7 +240,8 @@ void MergeTreeDataPartWide::calculateEachColumnSizes(ColumnSizeByName & each_col
         total_size.add(size);
 
 #ifndef NDEBUG
-        if (rows_count != 0 && column.type->isValueRepresentedByNumber())
+        /// Most trivial types
+        if (rows_count != 0 && column.type->isValueRepresentedByNumber() && !column.type->haveSubtypes())
         {
             size_t rows_in_column = size.data_uncompressed / column.type->getSizeOfValueInMemory();
             if (rows_in_column != rows_count)

From 3d743c5f75c1a05123a88c7b99be73d0d0fbacec Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Mon, 27 Jul 2020 12:52:04 +0300
Subject: [PATCH 12/25] Enable 00992 back

---
 tests/queries/skip_list.json | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/tests/queries/skip_list.json b/tests/queries/skip_list.json
index 31cb38cc6bf..955c67b0b96 100644
--- a/tests/queries/skip_list.json
+++ b/tests/queries/skip_list.json
@@ -55,8 +55,7 @@
         "01200_mutations_memory_consumption",
         "01103_check_cpu_instructions_at_startup",
         "01037_polygon_dicts_",
-        "hyperscan",
-        "00992_system_parts_race_condition_zookeeper"
+        "hyperscan"
     ],
     "unbundled-build": [
         "00429",

From 4b75be44a3734bd48d370f9caf8803e43aa3a38d Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Mon, 27 Jul 2020 16:04:13 +0300
Subject: [PATCH 13/25] Fix arcadia build

---
 src/Interpreters/MutationsInterpreter.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Interpreters/MutationsInterpreter.cpp b/src/Interpreters/MutationsInterpreter.cpp
index e502f517ad8..759543950de 100644
--- a/src/Interpreters/MutationsInterpreter.cpp
+++ b/src/Interpreters/MutationsInterpreter.cpp
@@ -768,7 +768,7 @@ bool MutationsInterpreter::Stage::isAffectingAllColumns(const Names & storage_co
 {
     /// is subset
     for (const auto & storage_column : storage_columns)
-        if (!output_columns.contains(storage_column))
+        if (!output_columns.count(storage_column))
             return false;
 
     return true;

From 4bd6261dc164c64172c641adafec271df4c12301 Mon Sep 17 00:00:00 2001
From: Yatsishin Ilya <2159081+qoega@users.noreply.github.com>
Date: Mon, 27 Jul 2020 20:00:14 +0300
Subject: [PATCH 14/25] Use prebuilt helper_container for integration tests

---
 tests/integration/helpers/network.py | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/tests/integration/helpers/network.py b/tests/integration/helpers/network.py
index 5d738126f07..f5c2b4f8d19 100644
--- a/tests/integration/helpers/network.py
+++ b/tests/integration/helpers/network.py
@@ -155,8 +155,6 @@ class _NetworkManager:
 
     def __init__(
             self,
-            image_name='clickhouse_tests_helper',
-            image_path=p.join(CLICKHOUSE_ROOT_DIR, 'docker', 'test', 'integration', 'helper_container'),
             container_expire_timeout=50, container_exit_timeout=60):
 
         self.container_expire_timeout = container_expire_timeout
@@ -164,14 +162,6 @@ class _NetworkManager:
 
         self._docker_client = docker.from_env(version=os.environ.get("DOCKER_API_VERSION"))
 
-        try:
-            self._image = self._docker_client.images.get(image_name)
-        except docker.errors.ImageNotFound:
-            # Use docker console client instead of python API to work around https://github.com/docker/docker-py/issues/1397
-            subprocess.check_call(
-                ['docker', 'build', '--force-rm', '--tag', image_name, '--network', 'host', image_path])
-            self._image = self._docker_client.images.get(image_name)
-
         self._container = None
 
         self._ensure_container()
@@ -185,15 +175,11 @@ class _NetworkManager:
                 except docker.errors.NotFound:
                     pass
 
-            # Work around https://github.com/docker/docker-py/issues/1477
-            host_config = self._docker_client.api.create_host_config(network_mode='host', auto_remove=True)
-            container_id = self._docker_client.api.create_container(
-                self._image.id, command=('sleep %s' % self.container_exit_timeout),
-                detach=True, host_config=host_config)['Id']
-
+            self._container = self._docker_client.containers.run('yandex/clickhouse-integration-helper', auto_remove=True,
+                                                                 command=('sleep %s' % self.container_exit_timeout),
+                                                                 detach=True, network_mode='host')
+            container_id = self._container.id
             self._container_expire_time = time.time() + self.container_expire_timeout
-            self._docker_client.api.start(container_id)
-            self._container = self._docker_client.containers.get(container_id)
 
         return self._container
 

From 1f8fe725eca2db3a59e0b715f992c9021f206af0 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Mon, 27 Jul 2020 22:35:38 +0300
Subject: [PATCH 15/25] Add test for ability to restore from backup

---
 .../__init__.py                               |   0
 .../test.py                                   | 130 ++++++++++++++++++
 2 files changed, 130 insertions(+)
 create mode 100644 tests/integration/test_backup_with_other_granularity/__init__.py
 create mode 100644 tests/integration/test_backup_with_other_granularity/test.py

diff --git a/tests/integration/test_backup_with_other_granularity/__init__.py b/tests/integration/test_backup_with_other_granularity/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/integration/test_backup_with_other_granularity/test.py b/tests/integration/test_backup_with_other_granularity/test.py
new file mode 100644
index 00000000000..43aa9562245
--- /dev/null
+++ b/tests/integration/test_backup_with_other_granularity/test.py
@@ -0,0 +1,130 @@
+import pytest
+
+
+from helpers.cluster import ClickHouseCluster
+cluster = ClickHouseCluster(__file__)
+
+
+node1 = cluster.add_instance('node1', with_zookeeper=True, image='yandex/clickhouse-server:19.4.5.35', stay_alive=True, with_installed_binary=True)
+node2 = cluster.add_instance('node2', with_zookeeper=True, image='yandex/clickhouse-server:19.4.5.35', stay_alive=True, with_installed_binary=True)
+node3 = cluster.add_instance('node3', with_zookeeper=True, image='yandex/clickhouse-server:19.4.5.35', stay_alive=True, with_installed_binary=True)
+
+
+@pytest.fixture(scope="module")
+def started_cluster():
+    try:
+        cluster.start()
+        yield cluster
+    finally:
+        cluster.shutdown()
+
+
+def test_backup_from_old_version(started_cluster):
+    node1.query("CREATE TABLE source_table(A Int64, B String) Engine = MergeTree order by tuple()")
+
+    node1.query("INSERT INTO source_table VALUES(1, '1')")
+
+    assert node1.query("SELECT COUNT() FROM source_table") == "1\n"
+
+    node1.query("ALTER TABLE source_table ADD COLUMN Y String")
+
+    node1.query("ALTER TABLE source_table FREEZE PARTITION tuple();")
+
+    node1.restart_with_latest_version()
+
+    node1.query("CREATE TABLE dest_table (A Int64,  B String,  Y String) ENGINE = ReplicatedMergeTree('/test/dest_table1', '1')  ORDER BY tuple()")
+
+    node1.query("INSERT INTO dest_table VALUES(2, '2', 'Hello')")
+
+    assert node1.query("SELECT COUNT() FROM dest_table") == "1\n"
+
+    node1.exec_in_container(['bash', '-c', 'cp -r /var/lib/clickhouse/shadow/1/data/default/source_table/all_1_1_0/ /var/lib/clickhouse/data/default/dest_table/detached'])
+
+    assert node1.query("SELECT COUNT() FROM dest_table") == "1\n"
+
+    node1.query("ALTER TABLE dest_table ATTACH PARTITION tuple()")
+
+    assert node1.query("SELECT sum(A) FROM dest_table") == "3\n"
+
+    node1.query("ALTER TABLE dest_table DETACH PARTITION tuple()")
+
+    node1.query("ALTER TABLE dest_table ATTACH PARTITION tuple()")
+
+    assert node1.query("SELECT sum(A) FROM dest_table") == "3\n"
+
+    assert node1.query("CHECK TABLE dest_table") == "1\n"
+
+
+def test_backup_from_old_version_setting(started_cluster):
+    node2.query("CREATE TABLE source_table(A Int64, B String) Engine = MergeTree order by tuple()")
+
+    node2.query("INSERT INTO source_table VALUES(1, '1')")
+
+    assert node2.query("SELECT COUNT() FROM source_table") == "1\n"
+
+    node2.query("ALTER TABLE source_table ADD COLUMN Y String")
+
+    node2.query("ALTER TABLE source_table FREEZE PARTITION tuple();")
+
+    node2.restart_with_latest_version()
+
+    node2.query("CREATE TABLE dest_table (A Int64,  B String,  Y String) ENGINE = ReplicatedMergeTree('/test/dest_table2', '1')  ORDER BY tuple() SETTINGS enable_mixed_granularity_parts = 1")
+
+    node2.query("INSERT INTO dest_table VALUES(2, '2', 'Hello')")
+
+    assert node2.query("SELECT COUNT() FROM dest_table") == "1\n"
+
+    node2.exec_in_container(['bash', '-c', 'cp -r /var/lib/clickhouse/shadow/1/data/default/source_table/all_1_1_0/ /var/lib/clickhouse/data/default/dest_table/detached'])
+
+    assert node2.query("SELECT COUNT() FROM dest_table") == "1\n"
+
+    node2.query("ALTER TABLE dest_table ATTACH PARTITION tuple()")
+
+    assert node2.query("SELECT sum(A) FROM dest_table") == "3\n"
+
+    node2.query("ALTER TABLE dest_table DETACH PARTITION tuple()")
+
+    node2.query("ALTER TABLE dest_table ATTACH PARTITION tuple()")
+
+    assert node2.query("SELECT sum(A) FROM dest_table") == "3\n"
+
+    assert node1.query("CHECK TABLE dest_table") == "1\n"
+
+
+def test_backup_from_old_version_config(started_cluster):
+    node3.query("CREATE TABLE source_table(A Int64, B String) Engine = MergeTree order by tuple()")
+
+    node3.query("INSERT INTO source_table VALUES(1, '1')")
+
+    assert node3.query("SELECT COUNT() FROM source_table") == "1\n"
+
+    node3.query("ALTER TABLE source_table ADD COLUMN Y String")
+
+    node3.query("ALTER TABLE source_table FREEZE PARTITION tuple();")
+
+    def callback(n):
+        n.replace_config("/etc/clickhouse-server/merge_tree_settings.xml", "<yandex><merge_tree><enable_mixed_granularity_parts>1</enable_mixed_granularity_parts></merge_tree></yandex>")
+
+    node3.restart_with_latest_version(callback_onstop=callback)
+
+    node3.query("CREATE TABLE dest_table (A Int64,  B String,  Y String) ENGINE = ReplicatedMergeTree('/test/dest_table3', '1')  ORDER BY tuple() SETTINGS enable_mixed_granularity_parts = 1")
+
+    node3.query("INSERT INTO dest_table VALUES(2, '2', 'Hello')")
+
+    assert node3.query("SELECT COUNT() FROM dest_table") == "1\n"
+
+    node3.exec_in_container(['bash', '-c', 'cp -r /var/lib/clickhouse/shadow/1/data/default/source_table/all_1_1_0/ /var/lib/clickhouse/data/default/dest_table/detached'])
+
+    assert node3.query("SELECT COUNT() FROM dest_table") == "1\n"
+
+    node3.query("ALTER TABLE dest_table ATTACH PARTITION tuple()")
+
+    assert node3.query("SELECT sum(A) FROM dest_table") == "3\n"
+
+    node3.query("ALTER TABLE dest_table DETACH PARTITION tuple()")
+
+    node3.query("ALTER TABLE dest_table ATTACH PARTITION tuple()")
+
+    assert node3.query("SELECT sum(A) FROM dest_table") == "3\n"
+
+    assert node1.query("CHECK TABLE dest_table") == "1\n"

From 1bece3de0aa7e431fbf2ba86ce161b0d46430f00 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Tue, 28 Jul 2020 12:36:08 +0300
Subject: [PATCH 16/25] Remove strange code and test

---
 src/Storages/MergeTree/MergeTreeData.cpp      |  5 -----
 .../test.py                                   | 22 +++++++++++++++++++
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/Storages/MergeTree/MergeTreeData.cpp b/src/Storages/MergeTree/MergeTreeData.cpp
index c71172850ba..abd88ab36a8 100644
--- a/src/Storages/MergeTree/MergeTreeData.cpp
+++ b/src/Storages/MergeTree/MergeTreeData.cpp
@@ -2408,11 +2408,6 @@ static void loadPartAndFixMetadataImpl(MergeTreeData::MutableDataPartPtr part)
     auto disk = part->volume->getDisk();
     String full_part_path = part->getFullRelativePath();
 
-    /// Earlier the list of  columns was written incorrectly. Delete it and re-create.
-    /// But in compact parts we can't get list of columns without this file.
-    if (isWidePart(part))
-        disk->removeIfExists(full_part_path + "columns.txt");
-
     part->loadColumnsChecksumsIndexes(false, true);
     part->modification_time = disk->getLastModified(full_part_path).epochTime();
 }
diff --git a/tests/integration/test_backup_with_other_granularity/test.py b/tests/integration/test_backup_with_other_granularity/test.py
index 43aa9562245..d4ca9bd1bac 100644
--- a/tests/integration/test_backup_with_other_granularity/test.py
+++ b/tests/integration/test_backup_with_other_granularity/test.py
@@ -8,6 +8,7 @@ cluster = ClickHouseCluster(__file__)
 node1 = cluster.add_instance('node1', with_zookeeper=True, image='yandex/clickhouse-server:19.4.5.35', stay_alive=True, with_installed_binary=True)
 node2 = cluster.add_instance('node2', with_zookeeper=True, image='yandex/clickhouse-server:19.4.5.35', stay_alive=True, with_installed_binary=True)
 node3 = cluster.add_instance('node3', with_zookeeper=True, image='yandex/clickhouse-server:19.4.5.35', stay_alive=True, with_installed_binary=True)
+node4 = cluster.add_instance('node4')
 
 
 @pytest.fixture(scope="module")
@@ -128,3 +129,24 @@ def test_backup_from_old_version_config(started_cluster):
     assert node3.query("SELECT sum(A) FROM dest_table") == "3\n"
 
     assert node1.query("CHECK TABLE dest_table") == "1\n"
+
+
+def test_backup_and_alter(started_cluster):
+    node4.query("CREATE TABLE backup_table(A Int64, B String, C Date) Engine = MergeTree order by tuple()")
+
+    node4.query("INSERT INTO backup_table VALUES(2, '2', toDate('2019-10-01'))")
+
+    node4.query("ALTER TABLE backup_table FREEZE PARTITION tuple();")
+
+    node4.query("ALTER TABLE backup_table DROP COLUMN C")
+
+    node4.query("ALTER TABLE backup_table MODIFY COLUMN B UInt64")
+
+    node4.query("ALTER TABLE backup_table DROP PARTITION tuple()")
+
+    node4.exec_in_container(['bash', '-c', 'cp -r /var/lib/clickhouse/shadow/1/data/default/backup_table/all_1_1_0/ /var/lib/clickhouse/data/default/backup_table/detached'])
+
+    node4.query("ALTER TABLE backup_table ATTACH PARTITION tuple()")
+
+    assert node4.query("SELECT sum(A) FROM backup_table") == "2\n"
+    assert node4.query("SELECT B + 2 FROM backup_table") == "4\n"

From eebb0233d93f033722ac8df370f9db14ec5ab763 Mon Sep 17 00:00:00 2001
From: Nikolai Kochetov <nik-kochetov@yandex-team.ru>
Date: Tue, 28 Jul 2020 13:41:32 +0300
Subject: [PATCH 17/25] Fix header for totals and extremes in
 QueryPipeline::unitePipelines.

---
 src/Processors/QueryPipeline.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Processors/QueryPipeline.cpp b/src/Processors/QueryPipeline.cpp
index f3635ac5408..f063b82e1b2 100644
--- a/src/Processors/QueryPipeline.cpp
+++ b/src/Processors/QueryPipeline.cpp
@@ -654,7 +654,7 @@ void QueryPipeline::unitePipelines(
         if (extremes.size() == 1)
             extremes_port = extremes.back();
         else
-            extremes_port = uniteExtremes(extremes, current_header, processors);
+            extremes_port = uniteExtremes(extremes, common_header, processors);
     }
 
     if (!totals.empty())
@@ -662,7 +662,7 @@ void QueryPipeline::unitePipelines(
         if (totals.size() == 1)
             totals_having_port = totals.back();
         else
-            totals_having_port = uniteTotals(totals, current_header, processors);
+            totals_having_port = uniteTotals(totals, common_header, processors);
     }
 
     current_header = common_header;

From f047194e11e8b53beaa1d1f13599158e2c2172fb Mon Sep 17 00:00:00 2001
From: Nikolai Kochetov <nik-kochetov@yandex-team.ru>
Date: Tue, 28 Jul 2020 13:45:10 +0300
Subject: [PATCH 18/25] Added test.

---
 .../01416_join_totals_header_bug.reference    |  0
 .../01416_join_totals_header_bug.sql          | 63 +++++++++++++++++++
 2 files changed, 63 insertions(+)
 create mode 100644 tests/queries/0_stateless/01416_join_totals_header_bug.reference
 create mode 100644 tests/queries/0_stateless/01416_join_totals_header_bug.sql

diff --git a/tests/queries/0_stateless/01416_join_totals_header_bug.reference b/tests/queries/0_stateless/01416_join_totals_header_bug.reference
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/queries/0_stateless/01416_join_totals_header_bug.sql b/tests/queries/0_stateless/01416_join_totals_header_bug.sql
new file mode 100644
index 00000000000..089a1d4b72f
--- /dev/null
+++ b/tests/queries/0_stateless/01416_join_totals_header_bug.sql
@@ -0,0 +1,63 @@
+DROP TABLE IF EXISTS tableCommon;
+DROP TABLE IF EXISTS tableTrees;
+DROP TABLE IF EXISTS tableFlowers;
+
+CREATE TABLE tableCommon (`key` FixedString(15), `value` Nullable(Int8)) ENGINE = Log();
+CREATE TABLE tableTrees (`key` FixedString(15), `name` Nullable(Int8), `name2` Nullable(Int8)) ENGINE = Log();
+CREATE TABLE tableFlowers (`key` FixedString(15), `name` Nullable(Int8)) ENGINE = Log();
+
+SELECT * FROM (
+    SELECT common.key, common.value, trees.name, trees.name2
+    FROM (
+	SELECT *
+	FROM tableCommon
+    ) as common
+    INNER JOIN (
+	SELECT *
+	FROM tableTrees
+    ) trees ON (common.key = trees.key)
+)
+UNION ALL
+(
+    SELECT common.key, common.value, 
+    null as name, null as name2 
+    
+    FROM (
+	SELECT *
+	FROM tableCommon
+    ) as common
+    INNER JOIN (
+	SELECT *
+	FROM tableFlowers
+    ) flowers ON (common.key = flowers.key)
+);
+
+SELECT * FROM (
+    SELECT common.key, common.value, trees.name, trees.name2
+    FROM (
+	SELECT *
+	FROM tableCommon
+    ) as common
+    INNER JOIN (
+	SELECT *
+	FROM tableTrees
+    ) trees ON (common.key = trees.key)
+)
+UNION ALL
+(
+    SELECT common.key, common.value, 
+    flowers.name, null as name2
+
+    FROM (
+	SELECT *
+	FROM tableCommon
+    ) as common
+    INNER JOIN (
+	SELECT *
+	FROM tableFlowers
+    ) flowers ON (common.key = flowers.key)
+);
+
+DROP TABLE IF EXISTS tableCommon;
+DROP TABLE IF EXISTS tableTrees;
+DROP TABLE IF EXISTS tableFlowers;

From 6dd731dd00e9afb3b3906a29559c2ac5689fef67 Mon Sep 17 00:00:00 2001
From: BayoNet <da-daos@yandex.ru>
Date: Tue, 28 Jul 2020 15:25:49 +0300
Subject: [PATCH 19/25] DOCS-590: parallel_distributed_insert_select (#12980)

* DOCSUP-987: parallel_distributed_insert_select setting (#145)

* add EN version

* add EN version

* changes after review in EN version

* add RU version

* CLICKHOUSEDOCS-590: Updated text

Co-authored-by: Evgenia Sudarikova <56156889+otrazhenia@users.noreply.github.com>
Co-authored-by: Sergei Shtykov <bayonet@yandex-team.ru>
---
 docs/en/operations/settings/settings.md | 14 ++++++++++++++
 docs/ru/operations/settings/settings.md | 13 +++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/docs/en/operations/settings/settings.md b/docs/en/operations/settings/settings.md
index 829fedc8deb..033ee880860 100644
--- a/docs/en/operations/settings/settings.md
+++ b/docs/en/operations/settings/settings.md
@@ -1459,6 +1459,20 @@ Possible values:
 
 Default value: 16.
 
+## parallel_distributed_insert_select {#parallel_distributed_insert_select}
+
+Enables parallel distributed `INSERT ... SELECT` query. 
+
+If we execute `INSERT INTO distributed_table_a SELECT ... FROM distributed_table_b` queries and both tables use the same cluster, and both tables are either [replicated](../../engines/table-engines/mergetree-family/replication.md) or non-replicated, then this query is processed locally on every shard.
+
+
+Possible values:
+
+-   0 — Disabled.
+-   1 — Enabled.
+
+Default value: 0.
+
 ## insert_distributed_sync {#insert_distributed_sync}
 
 Enables or disables synchronous data insertion into a [Distributed](../../engines/table-engines/special/distributed.md#distributed) table.
diff --git a/docs/ru/operations/settings/settings.md b/docs/ru/operations/settings/settings.md
index b8b64ae65c4..afb6a56ceb8 100644
--- a/docs/ru/operations/settings/settings.md
+++ b/docs/ru/operations/settings/settings.md
@@ -1278,6 +1278,19 @@ Default value: 0.
 
 Значение по умолчанию: 16.
 
+## parallel_distributed_insert_select {#parallel_distributed_insert_select}
+
+Включает параллельную обработку распределённых запросов `INSERT ... SELECT`.
+
+Если при выполнении запроса `INSERT INTO distributed_table_a SELECT ... FROM distributed_table_b` оказывается, что обе таблицы находятся в одном кластере, то независимо от того [реплицируемые](../../engines/table-engines/mergetree-family/replication.md) они или нет, запрос  выполняется локально на каждом шарде. 
+
+Допустимые значения:
+
+-   0 — выключена.
+-   1 — включена.
+
+Значение по умолчанию: 0.
+
 ## insert_distributed_sync {#insert_distributed_sync}
 
 Включает или отключает режим синхронного добавления данных в распределенные таблицы (таблицы с движком [Distributed](../../engines/table-engines/special/distributed.md#distributed)).

From cf503be085d72363f772ecf5a6d5295b50906781 Mon Sep 17 00:00:00 2001
From: Nikolai Kochetov <nik-kochetov@yandex-team.ru>
Date: Tue, 28 Jul 2020 15:27:23 +0300
Subject: [PATCH 20/25] Fix crash in ColumnTuple::updatePermutation

---
 src/Columns/ColumnTuple.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Columns/ColumnTuple.cpp b/src/Columns/ColumnTuple.cpp
index 4ce5ab7b2a3..87e5e37db51 100644
--- a/src/Columns/ColumnTuple.cpp
+++ b/src/Columns/ColumnTuple.cpp
@@ -349,7 +349,7 @@ void ColumnTuple::updatePermutation(bool reverse, size_t limit, int nan_directio
     for (const auto& column : columns)
     {
         column->updatePermutation(reverse, limit, nan_direction_hint, res, equal_range);
-        while (limit && limit <= equal_range.back().first)
+        while (limit && !equal_range.empty() && limit <= equal_range.back().first)
             equal_range.pop_back();
 
         if (equal_range.empty())

From c509ba691947ac771a2400112358ebf49af090e5 Mon Sep 17 00:00:00 2001
From: Nikolai Kochetov <nik-kochetov@yandex-team.ru>
Date: Tue, 28 Jul 2020 15:29:49 +0300
Subject: [PATCH 21/25] Added test.

---
 .../queries/0_stateless/01417_update_permutation_crash.reference | 1 +
 tests/queries/0_stateless/01417_update_permutation_crash.sql     | 1 +
 2 files changed, 2 insertions(+)
 create mode 100644 tests/queries/0_stateless/01417_update_permutation_crash.reference
 create mode 100644 tests/queries/0_stateless/01417_update_permutation_crash.sql

diff --git a/tests/queries/0_stateless/01417_update_permutation_crash.reference b/tests/queries/0_stateless/01417_update_permutation_crash.reference
new file mode 100644
index 00000000000..2b4f3eda2e0
--- /dev/null
+++ b/tests/queries/0_stateless/01417_update_permutation_crash.reference
@@ -0,0 +1 @@
+(1,1,0)
diff --git a/tests/queries/0_stateless/01417_update_permutation_crash.sql b/tests/queries/0_stateless/01417_update_permutation_crash.sql
new file mode 100644
index 00000000000..f5923781734
--- /dev/null
+++ b/tests/queries/0_stateless/01417_update_permutation_crash.sql
@@ -0,0 +1 @@
+select tuple(1, 1, number) as t from numbers_mt(1000001) order by t, number limit 1;

From e0c207d6b4f1977c9166081122f2dee1f351a646 Mon Sep 17 00:00:00 2001
From: Alexander Kuzmenkov <36882414+akuzm@users.noreply.github.com>
Date: Tue, 28 Jul 2020 16:15:41 +0300
Subject: [PATCH 22/25] Update entrypoint.sh

---
 docker/test/performance-comparison/entrypoint.sh | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/docker/test/performance-comparison/entrypoint.sh b/docker/test/performance-comparison/entrypoint.sh
index f9b90fce863..be087eb956c 100755
--- a/docker/test/performance-comparison/entrypoint.sh
+++ b/docker/test/performance-comparison/entrypoint.sh
@@ -4,6 +4,8 @@ set -ex
 # Use the packaged repository to find the revision we will compare to.
 function find_reference_sha
 {
+    git -C right/ch log -1 origin/master
+    git -C right/ch log -1 pr
     # Go back from the revision to be tested, trying to find the closest published
     # testing release. The PR branch may be either pull/*/head which is the
     # author's branch, or pull/*/merge, which is head merged with some master

From 2bde39349978a5160eaf1d95349d5ef0786150f1 Mon Sep 17 00:00:00 2001
From: Alexander Kazakov <Akazz@users.noreply.github.com>
Date: Tue, 28 Jul 2020 17:38:34 +0300
Subject: [PATCH 23/25] Merging #12548 - Correction to `merge_with_ttl_timeout`
 logic by @excitoon (#12982)

* Fixed `merge_with_ttl_timeout` logic.
* Separate TTL-merge timers for each partition

Co-authored-by: Vladimir Chebotarev <vladimir.chebotarev@gmail.com>
---
 .../MergeTree/MergeTreeDataMergerMutator.cpp  | 66 +++++++++----------
 .../MergeTree/MergeTreeDataMergerMutator.h    |  7 +-
 src/Storages/MergeTree/TTLMergeSelector.cpp   | 28 ++++++--
 src/Storages/MergeTree/TTLMergeSelector.h     | 15 ++++-
 tests/integration/test_ttl_replicated/test.py | 38 +++++++++++
 5 files changed, 112 insertions(+), 42 deletions(-)

diff --git a/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp b/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
index 2b407cb7269..9038e2a22f5 100644
--- a/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
+++ b/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp
@@ -30,13 +30,15 @@
 #include <Common/interpolate.h>
 #include <Common/typeid_cast.h>
 #include <Common/escapeForFileName.h>
-#include <cmath>
-#include <numeric>
-#include <iomanip>
 
+#include <cmath>
+#include <ctime>
+#include <iomanip>
+#include <numeric>
 
 #include <boost/algorithm/string/replace.hpp>
 
+
 namespace ProfileEvents
 {
     extern const Event MergedRows;
@@ -219,14 +221,13 @@ bool MergeTreeDataMergerMutator::selectPartsToMerge(
         return false;
     }
 
-    time_t current_time = time(nullptr);
+    time_t current_time = std::time(nullptr);
 
     IMergeSelector::Partitions partitions;
 
     const String * prev_partition_id = nullptr;
     /// Previous part only in boundaries of partition frame
     const MergeTreeData::DataPartPtr * prev_part = nullptr;
-    bool has_part_with_expired_ttl = false;
     for (const MergeTreeData::DataPartPtr & part : data_parts)
     {
         /// Check predicate only for first part in each partition.
@@ -258,11 +259,6 @@ bool MergeTreeDataMergerMutator::selectPartsToMerge(
         part_info.min_ttl = part->ttl_infos.part_min_ttl;
         part_info.max_ttl = part->ttl_infos.part_max_ttl;
 
-        time_t ttl = data_settings->ttl_only_drop_parts ? part_info.max_ttl : part_info.min_ttl;
-
-        if (ttl && ttl <= current_time)
-            has_part_with_expired_ttl = true;
-
         partitions.back().emplace_back(part_info);
 
         /// Check for consistency of data parts. If assertion is failed, it requires immediate investigation.
@@ -275,38 +271,38 @@ bool MergeTreeDataMergerMutator::selectPartsToMerge(
         prev_part = &part;
     }
 
-    std::unique_ptr<IMergeSelector> merge_selector;
+    IMergeSelector::PartsInPartition parts_to_merge;
 
-    SimpleMergeSelector::Settings merge_settings;
-    if (aggressive)
-        merge_settings.base = 1;
-
-    bool can_merge_with_ttl =
-        (current_time - last_merge_with_ttl > data_settings->merge_with_ttl_timeout);
-
-    /// NOTE Could allow selection of different merge strategy.
-    if (can_merge_with_ttl && has_part_with_expired_ttl && !ttl_merges_blocker.isCancelled())
+    if (!ttl_merges_blocker.isCancelled())
     {
-        merge_selector = std::make_unique<TTLMergeSelector>(current_time, data_settings->ttl_only_drop_parts);
-        last_merge_with_ttl = current_time;
+        TTLMergeSelector merge_selector(
+                next_ttl_merge_times_by_partition,
+                current_time,
+                data_settings->merge_with_ttl_timeout,
+                data_settings->ttl_only_drop_parts);
+        parts_to_merge = merge_selector.select(partitions, max_total_size_to_merge);
     }
-    else
-        merge_selector = std::make_unique<SimpleMergeSelector>(merge_settings);
-
-    IMergeSelector::PartsInPartition parts_to_merge = merge_selector->select(
-        partitions,
-        max_total_size_to_merge);
 
     if (parts_to_merge.empty())
     {
-        if (out_disable_reason)
-            *out_disable_reason = "There is no need to merge parts according to merge selector algorithm";
-        return false;
-    }
+        SimpleMergeSelector::Settings merge_settings;
+        if (aggressive)
+            merge_settings.base = 1;
 
-    /// Allow to "merge" part with itself if we need remove some values with expired ttl
-    if (parts_to_merge.size() == 1 && !has_part_with_expired_ttl)
-        throw Exception("Logical error: merge selector returned only one part to merge", ErrorCodes::LOGICAL_ERROR);
+        parts_to_merge = SimpleMergeSelector(merge_settings)
+                            .select(partitions, max_total_size_to_merge);
+
+        /// Do not allow to "merge" part with itself for regular merges, unless it is a TTL-merge where it is ok to remove some values with expired ttl
+        if (parts_to_merge.size() == 1)
+            throw Exception("Logical error: merge selector returned only one part to merge", ErrorCodes::LOGICAL_ERROR);
+
+        if (parts_to_merge.empty())
+        {
+            if (out_disable_reason)
+                *out_disable_reason = "There is no need to merge parts according to merge selector algorithm";
+            return false;
+        }
+    }
 
     MergeTreeData::DataPartsVector parts;
     parts.reserve(parts_to_merge.size());
diff --git a/src/Storages/MergeTree/MergeTreeDataMergerMutator.h b/src/Storages/MergeTree/MergeTreeDataMergerMutator.h
index 121cc770d51..3c7fcd99f95 100644
--- a/src/Storages/MergeTree/MergeTreeDataMergerMutator.h
+++ b/src/Storages/MergeTree/MergeTreeDataMergerMutator.h
@@ -5,6 +5,7 @@
 #include <atomic>
 #include <functional>
 #include <Common/ActionBlocker.h>
+#include <Storages/MergeTree/TTLMergeSelector.h>
 
 
 namespace DB
@@ -242,8 +243,10 @@ private:
     /// When the last time you wrote to the log that the disk space was running out (not to write about this too often).
     time_t disk_space_warning_time = 0;
 
-    /// Last time when TTLMergeSelector has been used
-    time_t last_merge_with_ttl = 0;
+    /// Stores the next TTL merge due time for each partition (used only by TTLMergeSelector)
+    TTLMergeSelector::PartitionIdToTTLs next_ttl_merge_times_by_partition;
+    /// Performing TTL merges independently for each partition guarantees that
+    /// there is only a limited number of TTL merges and no partition stores data, that is too stale
 };
 
 
diff --git a/src/Storages/MergeTree/TTLMergeSelector.cpp b/src/Storages/MergeTree/TTLMergeSelector.cpp
index 0ba341fca64..1966f2a4f0a 100644
--- a/src/Storages/MergeTree/TTLMergeSelector.cpp
+++ b/src/Storages/MergeTree/TTLMergeSelector.cpp
@@ -1,12 +1,20 @@
 #include <Storages/MergeTree/TTLMergeSelector.h>
+#include <Storages/MergeTree/MergeTreeData.h>
 
-#include <cmath>
 #include <algorithm>
+#include <cmath>
 
 
 namespace DB
 {
 
+const String & getPartitionIdForPart(const TTLMergeSelector::Part & part_info)
+{
+    const MergeTreeData::DataPartPtr & part = *static_cast<const MergeTreeData::DataPartPtr *>(part_info.data);
+    return part->info.partition_id;
+}
+
+
 IMergeSelector::PartsInPartition TTLMergeSelector::select(
     const Partitions & partitions,
     const size_t max_total_size_to_merge)
@@ -18,15 +26,24 @@ IMergeSelector::PartsInPartition TTLMergeSelector::select(
 
     for (size_t i = 0; i < partitions.size(); ++i)
     {
-        for (auto it = partitions[i].begin(); it != partitions[i].end(); ++it)
+        const auto & mergeable_parts_in_partition = partitions[i];
+        if (mergeable_parts_in_partition.empty())
+            continue;
+
+        const auto & partition_id = getPartitionIdForPart(mergeable_parts_in_partition.front());
+        const auto & next_merge_time_for_partition = merge_due_times[partition_id];
+        if (next_merge_time_for_partition > current_time)
+            continue;
+
+        for (Iterator part_it = mergeable_parts_in_partition.cbegin(); part_it != mergeable_parts_in_partition.cend(); ++part_it)
         {
-            time_t ttl = only_drop_parts ? it->max_ttl : it->min_ttl;
+            time_t ttl = only_drop_parts ? part_it->max_ttl : part_it->min_ttl;
 
             if (ttl && (partition_to_merge_index == -1 || ttl < partition_to_merge_min_ttl))
             {
                 partition_to_merge_min_ttl = ttl;
                 partition_to_merge_index = i;
-                best_begin = it;
+                best_begin = part_it;
             }
         }
     }
@@ -68,6 +85,9 @@ IMergeSelector::PartsInPartition TTLMergeSelector::select(
         ++best_end;
     }
 
+    const auto & best_partition_id = getPartitionIdForPart(best_partition.front());
+    merge_due_times[best_partition_id] = current_time + merge_cooldown_time;
+
     return PartsInPartition(best_begin, best_end);
 }
 
diff --git a/src/Storages/MergeTree/TTLMergeSelector.h b/src/Storages/MergeTree/TTLMergeSelector.h
index 2f03d5b9feb..5b7361d2d2b 100644
--- a/src/Storages/MergeTree/TTLMergeSelector.h
+++ b/src/Storages/MergeTree/TTLMergeSelector.h
@@ -1,7 +1,10 @@
 #pragma once
 
+#include <Core/Types.h>
 #include <Storages/MergeTree/MergeSelector.h>
 
+#include <map>
+
 
 namespace DB
 {
@@ -10,17 +13,27 @@ namespace DB
   * It selects parts to merge by greedy algorithm: 
   *  1. Finds part with the most earliest expired ttl and includes it to result.
   *  2. Tries to find the longest range of parts with expired ttl, that includes part from step 1.
+  * Finally, merge selector updates TTL merge timer for the selected partition
   */
 class TTLMergeSelector : public IMergeSelector
 {
 public:
-    explicit TTLMergeSelector(time_t current_time_, bool only_drop_parts_) : current_time(current_time_), only_drop_parts(only_drop_parts_) {}
+    using PartitionIdToTTLs = std::map<String, time_t>;
+
+    explicit TTLMergeSelector(PartitionIdToTTLs & merge_due_times_, time_t current_time_, Int64 merge_cooldown_time_, bool only_drop_parts_)
+        : merge_due_times(merge_due_times_),
+          current_time(current_time_),
+          merge_cooldown_time(merge_cooldown_time_),
+          only_drop_parts(only_drop_parts_) {}
 
     PartsInPartition select(
         const Partitions & partitions,
         const size_t max_total_size_to_merge) override;
+
 private:
+    PartitionIdToTTLs & merge_due_times;
     time_t current_time;
+    Int64 merge_cooldown_time;
     bool only_drop_parts;
 };
 
diff --git a/tests/integration/test_ttl_replicated/test.py b/tests/integration/test_ttl_replicated/test.py
index a458db07a23..0f201f569b3 100644
--- a/tests/integration/test_ttl_replicated/test.py
+++ b/tests/integration/test_ttl_replicated/test.py
@@ -5,10 +5,12 @@ import helpers.client as client
 from helpers.cluster import ClickHouseCluster
 from helpers.test_tools import TSV
 
+
 cluster = ClickHouseCluster(__file__)
 node1 = cluster.add_instance('node1', with_zookeeper=True)
 node2 = cluster.add_instance('node2', with_zookeeper=True)
 
+
 @pytest.fixture(scope="module")
 def started_cluster():
     try:
@@ -22,11 +24,13 @@ def started_cluster():
     finally:
         cluster.shutdown()
 
+
 def drop_table(nodes, table_name):
     for node in nodes:
         node.query("DROP TABLE IF EXISTS {} NO DELAY".format(table_name))
     time.sleep(1)
 
+
 def test_ttl_columns(started_cluster):
     drop_table([node1, node2], "test_ttl")
     for node in [node1, node2]:
@@ -47,6 +51,40 @@ def test_ttl_columns(started_cluster):
     assert TSV(node2.query("SELECT id, a, b FROM test_ttl ORDER BY id")) == TSV(expected)
 
 
+def test_merge_with_ttl_timeout(started_cluster):
+    table = "test_merge_with_ttl_timeout"
+    drop_table([node1, node2], table)
+    for node in [node1, node2]:
+        node.query(
+        '''
+            CREATE TABLE {table}(date DateTime, id UInt32, a Int32 TTL date + INTERVAL 1 DAY, b Int32 TTL date + INTERVAL 1 MONTH)
+            ENGINE = ReplicatedMergeTree('/clickhouse/tables/test/{table}', '{replica}')
+            ORDER BY id PARTITION BY toDayOfMonth(date);
+        '''.format(replica=node.name, table=table))
+
+    node1.query("SYSTEM STOP TTL MERGES {table}".format(table=table))
+    node2.query("SYSTEM STOP TTL MERGES {table}".format(table=table))
+
+    for i in range(1, 4):
+        node1.query("INSERT INTO {table} VALUES (toDateTime('2000-10-{day:02d} 10:00:00'), 1, 2, 3)".format(day=i, table=table))
+
+    assert node1.query("SELECT countIf(a = 0) FROM {table}".format(table=table)) == "0\n"
+    assert node2.query("SELECT countIf(a = 0) FROM {table}".format(table=table)) == "0\n"
+
+    node1.query("SYSTEM START TTL MERGES {table}".format(table=table))
+    node2.query("SYSTEM START TTL MERGES {table}".format(table=table))
+
+    time.sleep(15) # TTL merges shall happen.
+
+    for i in range(1, 4):
+        node1.query("INSERT INTO {table} VALUES (toDateTime('2000-10-{day:02d} 10:00:00'), 1, 2, 3)".format(day=i, table=table))
+
+    time.sleep(15) # TTL merges shall not happen.
+
+    assert node1.query("SELECT countIf(a = 0) FROM {table}".format(table=table)) == "3\n"
+    assert node2.query("SELECT countIf(a = 0) FROM {table}".format(table=table)) == "3\n"
+
+
 def test_ttl_many_columns(started_cluster):
     drop_table([node1, node2], "test_ttl_2")
     for node in [node1, node2]:

From 8225bc13fe34aeeda5620f5eb1af2a232d5f58ce Mon Sep 17 00:00:00 2001
From: alexey-milovidov <milovidov@yandex-team.ru>
Date: Tue, 28 Jul 2020 21:42:30 +0300
Subject: [PATCH 24/25] Fix terrible unbearable data rot. CC @blinkov

---
 docs/en/getting-started/example-datasets/metrica.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/en/getting-started/example-datasets/metrica.md b/docs/en/getting-started/example-datasets/metrica.md
index a9cf80716ce..4131dca78fe 100644
--- a/docs/en/getting-started/example-datasets/metrica.md
+++ b/docs/en/getting-started/example-datasets/metrica.md
@@ -7,7 +7,7 @@ toc_title: Yandex.Metrica Data
 
 Dataset consists of two tables containing anonymized data about hits (`hits_v1`) and visits (`visits_v1`) of Yandex.Metrica. You can read more about Yandex.Metrica in [ClickHouse history](../../introduction/history.md) section.
 
-The dataset consists of two tables, either of them can be downloaded as a compressed `tsv.xz` file or as prepared partitions. In addition to that, an extended version of the `hits` table containing 100 million rows is available as TSV at https://clickhouse-datasets.s3.yandex.net/hits/tsv/hits\_100m\_obfuscated\_v1.tsv.xz and as prepared partitions at https://clickhouse-datasets.s3.yandex.net/hits/partitions/hits\_100m\_obfuscated\_v1.tar.xz.
+The dataset consists of two tables, either of them can be downloaded as a compressed `tsv.xz` file or as prepared partitions. In addition to that, an extended version of the `hits` table containing 100 million rows is available as TSV at https://clickhouse-datasets.s3.yandex.net/hits/tsv/hits_100m_obfuscated_v1.tsv.xz and as prepared partitions at https://clickhouse-datasets.s3.yandex.net/hits/partitions/hits_100m_obfuscated_v1.tar.xz.
 
 ## Obtaining Tables from Prepared Partitions {#obtaining-tables-from-prepared-partitions}
 

From 9e62fa1c5ab29d31697be32dc144e515dabc99a0 Mon Sep 17 00:00:00 2001
From: Ivan Blinkov <github@blinkov.ru>
Date: Tue, 28 Jul 2020 22:38:52 +0300
Subject: [PATCH 25/25] [docs] maybe fix build

---
 docs/en/operations/system-tables/metric_log.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/docs/en/operations/system-tables/metric_log.md b/docs/en/operations/system-tables/metric_log.md
index 91d8553683e..1e38eb7e247 100644
--- a/docs/en/operations/system-tables/metric_log.md
+++ b/docs/en/operations/system-tables/metric_log.md
@@ -50,6 +50,6 @@ CurrentMetric_ReplicatedChecks:                             0
 **See also**
 
 -   [system.asynchronous\_metrics](../../operations/system-tables/asynchronous_metrics.md) — Contains periodically calculated metrics.
--   [system.events](../../operations/system-tables/events.md) — Contains a number of events that occurred.
+-   [system.events](../../operations/system-tables/events.md#system_tables-events) — Contains a number of events that occurred.
 -   [system.metrics](../../operations/system-tables/metrics.md) — Contains instantly calculated metrics.
 -   [Monitoring](../../operations/monitoring.md) — Base concepts of ClickHouse monitoring.