Merge branch 'master' into fix-access-gtest-in-arcadia

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

@@ -43,10 +43,10 @@ CREATE DATABASE mysql ENGINE = MaterializedMySQL('localhost:3306', 'db', 'user',
 
 **Settings on MySQL-server side**
 
-For the correct work of `MaterializeMySQL`, there are few mandatory `MySQL`-side configuration settings that should be set:
+For the correct work of `MaterializedMySQL`, there are few mandatory `MySQL`-side configuration settings that should be set:
 
-- `default_authentication_plugin = mysql_native_password` since `MaterializeMySQL` can only authorize with this method.
-- `gtid_mode = on` since GTID based logging is a mandatory for providing correct `MaterializeMySQL` replication. Pay attention that while turning this mode `On` you should also specify `enforce_gtid_consistency = on`.
+- `default_authentication_plugin = mysql_native_password` since `MaterializedMySQL` can only authorize with this method.
+- `gtid_mode = on` since GTID based logging is a mandatory for providing correct `MaterializedMySQL` replication. Pay attention that while turning this mode `On` you should also specify `enforce_gtid_consistency = on`.
 
 ## Virtual columns {#virtual-columns}
 

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

@@ -125,6 +125,44 @@ Result:
 └───────────────────────────┘
 ```
 
+## subBitmap {#subBitmap}
+
+Creates a subset of bitmap limit the results to `cardinality_limit` with offset of `offset`.
+
+**Syntax**
+
+``` sql
+subBitmap(bitmap, offset, cardinality_limit)
+```
+
+**Arguments**
+
+-   `bitmap` – [Bitmap object](#bitmap_functions-bitmapbuild).
+-   `offset` – the number of offsets. Type: [UInt32](../../sql-reference/data-types/int-uint.md).
+-   `cardinality_limit` – The subset cardinality upper limit. Type: [UInt32](../../sql-reference/data-types/int-uint.md).
+
+**Returned value**
+
+The subset.
+
+Type: `Bitmap object`.
+
+**Example**
+
+Query:
+
+``` sql
+SELECT bitmapToArray(subBitmap(bitmapBuild([0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,100,200,500]), toUInt32(10), toUInt32(10))) AS res;
+```
+
+Result:
+
+``` text
+┌─res─────────────────────────────┐
+│ [10,11,12,13,14,15,16,17,18,19] │
+└─────────────────────────────────┘
+```
+
 ## bitmapContains {#bitmap_functions-bitmapcontains}
 
 Checks whether the bitmap contains an element.

docs/zh/sql-reference/functions/bitmap-functions.md

@@ -88,6 +88,30 @@ SELECT bitmapToArray(bitmapSubsetLimit(bitmapBuild([0,1,2,3,4,5,6,7,8,9,10,11,12
     │ [30,31,32,33,100,200,500] │
     └───────────────────────────┘
 
+## subBitmap {#subBitmap}
+
+将位图跳过`offset`个元素，限制大小为`limit`个的结果转换为另一个位图。
+
+    subBitmap(bitmap, offset, limit)
+
+**参数**
+
+-   `bitmap` – 位图对象.
+-   `offset` – 跳过多少个元素.
+-   `limit` – 子位图基数上限.
+
+**示例**
+
+``` sql
+SELECT bitmapToArray(subBitmap(bitmapBuild([0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,100,200,500]), toUInt32(10), toUInt32(10))) AS res
+```
+
+```text
+┌─res─────────────────────────────┐
+│ [10,11,12,13,14,15,16,17,18,19] │
+└─────────────────────────────────┘
+```
+
 ## bitmapContains {#bitmapcontains}
 
 检查位图是否包含指定元素。

programs/client/Client.cpp

@@ -1,3 +1,6 @@
+#include <string>
+#include "Common/MemoryTracker.h"
+#include "Columns/ColumnsNumber.h"
 #include "ConnectionParameters.h"
 #include "QueryFuzzer.h"
 #include "Suggest.h"
@@ -100,6 +103,14 @@
 #pragma GCC optimize("-fno-var-tracking-assignments")
 #endif
 
+namespace CurrentMetrics
+{
+    extern const Metric Revision;
+    extern const Metric VersionInteger;
+    extern const Metric MemoryTracking;
+    extern const Metric MaxDDLEntryID;
+}
+
 namespace fs = std::filesystem;
 
 namespace DB
@@ -524,6 +535,18 @@ private:
     {
         UseSSL use_ssl;
 
+        MainThreadStatus::getInstance();
+
+        /// Limit on total memory usage
+        size_t max_client_memory_usage = config().getInt64("max_memory_usage_in_client", 0 /*default value*/);
+
+        if (max_client_memory_usage != 0)
+        {
+            total_memory_tracker.setHardLimit(max_client_memory_usage);
+            total_memory_tracker.setDescription("(total)");
+            total_memory_tracker.setMetric(CurrentMetrics::MemoryTracking);
+        }
+
         registerFormats();
         registerFunctions();
         registerAggregateFunctions();
@@ -2581,6 +2604,7 @@ public:
             ("opentelemetry-tracestate", po::value<std::string>(), "OpenTelemetry tracestate header as described by W3C Trace Context recommendation")
             ("history_file", po::value<std::string>(), "path to history file")
             ("no-warnings", "disable warnings when client connects to server")
+            ("max_memory_usage_in_client", po::value<int>(), "sets memory limit in client")
         ;
 
         Settings cmd_settings;

programs/server/play.html

@@ -68,7 +68,7 @@
         html, body
         {
             /* Personal choice. */
-            font-family: Sans-Serif;
+            font-family: Liberation Sans, DejaVu Sans, sans-serif, Noto Color Emoji, Apple Color Emoji, Segoe UI Emoji;
             background: var(--background-color);
             color: var(--text-color);
         }
@@ -96,11 +96,16 @@
         .monospace
         {
             /* Prefer fonts that have full hinting info. This is important for non-retina displays.
-               Also I personally dislike "Ubuntu" font due to the similarity of 'r' and 'г' (it looks very ignorant).
-            */
+               Also I personally dislike "Ubuntu" font due to the similarity of 'r' and 'г' (it looks very ignorant). */
             font-family: Liberation Mono, DejaVu Sans Mono, MonoLisa, Consolas, Monospace;
         }
 
+        .monospace-table
+        {
+            /* Liberation is worse than DejaVu for block drawing characters. */
+            font-family: DejaVu Sans Mono, Liberation Mono, MonoLisa, Consolas, Monospace;
+        }
+
         .shadow
         {
             box-shadow: 0 0 1rem var(--shadow-color);
@@ -325,8 +330,8 @@
         <span id="toggle-dark">🌑</span><span id="toggle-light">🌞</span>
     </div>
     <div id="data_div">
-        <table class="monospace shadow" id="data-table"></table>
-        <pre class="monospace shadow" id="data-unparsed"></pre>
+        <table class="monospace-table shadow" id="data-table"></table>
+        <pre class="monospace-table shadow" id="data-unparsed"></pre>
     </div>
     <svg id="graph" fill="none"></svg>
     <p id="error" class="monospace shadow">
@@ -367,7 +372,7 @@
         const server_address = document.getElementById('url').value;
 
         const url = server_address +
-            (server_address.indexOf('?') >= 0 ? '&' : '?') + 
+            (server_address.indexOf('?') >= 0 ? '&' : '?') +
             /// Ask server to allow cross-domain requests.
             'add_http_cors_header=1' +
             '&user=' + encodeURIComponent(user) +

src/AggregateFunctions/AggregateFunctionGroupBitmapData.h

@@ -579,6 +579,37 @@ public:
         }
     }
 
+    UInt64 rb_offset_limit(UInt64 offset, UInt64 limit, RoaringBitmapWithSmallSet & r1) const
+    {
+        if (limit == 0 || offset >= size())
+            return 0;
+
+        if (isSmall())
+        {
+            UInt64 count = 0;
+            UInt64 offset_count = 0;
+            auto it = small.begin();
+            for (;it != small.end() && offset_count < offset; ++it)
+                ++offset_count;
+
+            for (;it != small.end() && count < limit; ++it, ++count)
+                r1.add(it->getValue());
+            return count;
+        }
+        else
+        {
+            UInt64 count = 0;
+            UInt64 offset_count = 0;
+            auto it = rb->begin();
+            for (;it != rb->end() && offset_count < offset; ++it)
+                ++offset_count;
+
+            for (;it != rb->end() && count < limit; ++it, ++count)
+                r1.add(*it);
+            return count;
+        }
+    }
+
     UInt64 rb_min() const
     {
         if (isSmall())

src/Core/Block.cpp

@@ -44,6 +44,13 @@ void Block::initializeIndexByName()
 }
 
 
+void Block::reserve(size_t count)
+{
+    index_by_name.reserve(count);
+    data.reserve(count);
+}
+
+
 void Block::insert(size_t position, ColumnWithTypeAndName elem)
 {
     if (position > data.size())
@@ -287,6 +294,7 @@ std::string Block::dumpIndex() const
 Block Block::cloneEmpty() const
 {
     Block res;
+    res.reserve(data.size());
 
     for (const auto & elem : data)
         res.insert(elem.cloneEmpty());
@@ -364,6 +372,8 @@ Block Block::cloneWithColumns(MutableColumns && columns) const
     Block res;
 
     size_t num_columns = data.size();
+    res.reserve(num_columns);
+
     for (size_t i = 0; i < num_columns; ++i)
         res.insert({ std::move(columns[i]), data[i].type, data[i].name });
 
@@ -381,6 +391,8 @@ Block Block::cloneWithColumns(const Columns & columns) const
         throw Exception("Cannot clone block with columns because block has " + toString(num_columns) + " columns, "
                         "but " + toString(columns.size()) + " columns given.", ErrorCodes::LOGICAL_ERROR);
 
+    res.reserve(num_columns);
+
     for (size_t i = 0; i < num_columns; ++i)
         res.insert({ columns[i], data[i].type, data[i].name });
 
@@ -393,6 +405,8 @@ Block Block::cloneWithoutColumns() const
     Block res;
 
     size_t num_columns = data.size();
+    res.reserve(num_columns);
+
     for (size_t i = 0; i < num_columns; ++i)
         res.insert({ nullptr, data[i].type, data[i].name });
 

src/Core/Block.h

@@ -152,6 +152,7 @@ public:
 private:
     void eraseImpl(size_t position);
     void initializeIndexByName();
+    void reserve(size_t count);
 
     /// This is needed to allow function execution over data.
     /// It is safe because functions does not change column names, so index is unaffected.

src/Core/ya.make

@@ -31,6 +31,10 @@ SRCS(
     MySQL/PacketsProtocolText.cpp
     MySQL/PacketsReplication.cpp
     NamesAndTypes.cpp
+    PostgreSQL/Connection.cpp
+    PostgreSQL/PoolWithFailover.cpp
+    PostgreSQL/Utils.cpp
+    PostgreSQL/insertPostgreSQLValue.cpp
     PostgreSQLProtocol.cpp
     QueryProcessingStage.cpp
     Settings.cpp

src/DataStreams/ya.make

@@ -49,6 +49,7 @@ SRCS(
     TTLUpdateInfoAlgorithm.cpp
     copyData.cpp
     finalizeBlock.cpp
+    formatBlock.cpp
     materializeBlock.cpp
     narrowBlockInputStreams.cpp
 

src/Functions/FunctionsBitmap.cpp

@@ -13,6 +13,7 @@ void registerFunctionsBitmap(FunctionFactory & factory)
     factory.registerFunction<FunctionBitmapToArray>();
     factory.registerFunction<FunctionBitmapSubsetInRange>();
     factory.registerFunction<FunctionBitmapSubsetLimit>();
+    factory.registerFunction<FunctionBitmapSubsetOffsetLimit>();
     factory.registerFunction<FunctionBitmapTransform>();
 
     factory.registerFunction<FunctionBitmapSelfCardinality>();

src/Functions/FunctionsBitmap.h

@@ -460,9 +460,24 @@ public:
     }
 };
 
+struct BitmapSubsetOffsetLimitImpl
+{
+public:
+    static constexpr auto name = "subBitmap";
+    template <typename T>
+    static void apply(
+        const AggregateFunctionGroupBitmapData<T> & bitmap_data_0,
+        UInt64 range_start,
+        UInt64 range_end,
+        AggregateFunctionGroupBitmapData<T> & bitmap_data_2)
+        {
+        bitmap_data_0.rbs.rb_offset_limit(range_start, range_end, bitmap_data_2.rbs);
+        }
+};
+
 using FunctionBitmapSubsetInRange = FunctionBitmapSubset<BitmapSubsetInRangeImpl>;
 using FunctionBitmapSubsetLimit = FunctionBitmapSubset<BitmapSubsetLimitImpl>;
-
+using FunctionBitmapSubsetOffsetLimit = FunctionBitmapSubset<BitmapSubsetOffsetLimitImpl>;
 
 class FunctionBitmapTransform : public IFunction
 {

src/Interpreters/AsynchronousMetrics.cpp

@@ -1091,7 +1091,14 @@ void AsynchronousMetrics::update(std::chrono::system_clock::time_point update_ti
             {
                 sensor_file->rewind();
                 Int64 temperature = 0;
-                readText(temperature, *sensor_file);
+                try
+                {
+                    readText(temperature, *sensor_file);
+                }
+                catch (const ErrnoException & e)
+                {
+                    LOG_DEBUG(&Poco::Logger::get("AsynchronousMetrics"), "Hardware monitor '{}', sensor '{}' exists but could not be read, error {}.", hwmon_name, sensor_name, e.getErrno());
+                }
 
                 if (sensor_name.empty())
                     new_values[fmt::format("Temperature_{}", hwmon_name)] = temperature * 0.001;

src/Parsers/ya.make

@@ -21,6 +21,7 @@ SRCS(
     ASTCreateRowPolicyQuery.cpp
     ASTCreateSettingsProfileQuery.cpp
     ASTCreateUserQuery.cpp
+    ASTDatabaseOrNone.cpp
     ASTDictionary.cpp
     ASTDictionaryAttributeDeclaration.cpp
     ASTDropAccessEntityQuery.cpp
@@ -95,6 +96,7 @@ SRCS(
     ParserCreateSettingsProfileQuery.cpp
     ParserCreateUserQuery.cpp
     ParserDataType.cpp
+    ParserDatabaseOrNone.cpp
     ParserDescribeTableQuery.cpp
     ParserDictionary.cpp
     ParserDictionaryAttributeDeclaration.cpp

src/Processors/Transforms/WindowTransform.cpp

@@ -1166,6 +1166,23 @@ void WindowTransform::appendChunk(Chunk & chunk)
             // Write out the aggregation results.
             writeOutCurrentRow();
 
+            if (isCancelled())
+            {
+                // Good time to check if the query is cancelled. Checking once
+                // per block might not be enough in severe quadratic cases.
+                // Just leave the work halfway through and return, the 'prepare'
+                // method will figure out what to do. Note that this doesn't
+                // handle 'max_execution_time' and other limits, because these
+                // limits are only updated between blocks. Eventually we should
+                // start updating them in background and canceling the processor,
+                // like we do for Ctrl+C handling.
+                //
+                // This class is final, so the check should hopefully be
+                // devirtualized and become a single never-taken branch that is
+                // basically free.
+                return;
+            }
+
             // Move to the next row. The frame will have to be recalculated.
             // The peer group start is updated at the beginning of the loop,
             // because current_row might now be past-the-end.
@@ -1255,10 +1272,12 @@ IProcessor::Status WindowTransform::prepare()
 //        next_output_block_number, first_not_ready_row, first_block_number,
 //        blocks.size());
 
-    if (output.isFinished())
+    if (output.isFinished() || isCancelled())
     {
         // The consumer asked us not to continue (or we decided it ourselves),
-        // so we abort.
+        // so we abort. Not sure what the difference between the two conditions
+        // is, but it seemed that output.isFinished() is not enough to cancel on
+        // Ctrl+C. Test manually if you change it.
         input.close();
         return Status::Finished;
     }

src/Processors/Transforms/WindowTransform.h

@@ -80,8 +80,10 @@ struct RowNumber
  * the order of input data. This property also trivially holds for the ROWS and
  * GROUPS frames. For the RANGE frame, the proof requires the additional fact
  * that the ranges are specified in terms of (the single) ORDER BY column.
+ *
+ * `final` is so that the isCancelled() is devirtualized, we call it every row.
  */
-class WindowTransform : public IProcessor /* public ISimpleTransform */
+class WindowTransform final : public IProcessor
 {
 public:
     WindowTransform(

src/Processors/ya.make

@@ -31,11 +31,6 @@ SRCS(
     Formats/IOutputFormat.cpp
     Formats/IRowInputFormat.cpp
     Formats/IRowOutputFormat.cpp
-    Formats/Impl/ArrowBlockInputFormat.cpp
-    Formats/Impl/ArrowBlockOutputFormat.cpp
-    Formats/Impl/ArrowBufferedStreams.cpp
-    Formats/Impl/ArrowColumnToCHColumn.cpp
-    Formats/Impl/CHColumnToArrowColumn.cpp
     Formats/Impl/BinaryRowInputFormat.cpp
     Formats/Impl/BinaryRowOutputFormat.cpp
     Formats/Impl/CSVRowInputFormat.cpp

src/Storages/ya.make

@@ -141,6 +141,7 @@ SRCS(
     StorageMerge.cpp
     StorageMergeTree.cpp
     StorageMongoDB.cpp
+    StorageMongoDBSocketFactory.cpp
     StorageMySQL.cpp
     StorageNull.cpp
     StorageReplicatedMergeTree.cpp

tests/clickhouse-test

@@ -647,7 +647,7 @@ def run_tests_array(all_tests_with_params):
                         failures_chain += 1
                         status += MSG_FAIL
                         status += print_test_time(total_time)
-                        status += " - having exception:\n{}\n".format(
+                        status += " - having exception in stdout:\n{}\n".format(
                             '\n'.join(stdout.split('\n')[:100]))
                         status += 'Database: ' + testcase_args.testcase_database
                     elif reference_file is None:

tests/queries/0_stateless/00829_bitmap_function.reference

@@ -91,6 +91,14 @@ tag4	[0,1,2,3,4,5,6,7,8,9]	[5,999,2]	[2,888,20]	[0,1,3,4,6,7,8,9,20]
 [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,100,200,500]
 [30,31,32,33,100,200,500]
 [100,200,500]
+[]
+[]
+[1,5,7,9]
+[5,7,9]
+[5,7]
+[0,1,2,3,4,5,6,7,8,9]
+[30,31,32,33,100,200,500]
+[100,200,500]
 0
 0
 0

tests/queries/0_stateless/00829_bitmap_function.sql

@@ -286,6 +286,25 @@ select bitmapToArray(bitmapSubsetLimit(bitmapBuild([
     0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,
     100,200,500]), toUInt32(100), toUInt16(200)));
 
+-- subBitmap:
+---- Empty
+SELECT bitmapToArray(subBitmap(bitmapBuild(emptyArrayUInt32()), toUInt8(0), toUInt32(10)));
+SELECT bitmapToArray(subBitmap(bitmapBuild(emptyArrayUInt16()), toUInt32(0), toUInt64(10)));
+---- Small
+select bitmapToArray(subBitmap(bitmapBuild([1,5,7,9]), toUInt8(0), toUInt32(4)));
+select bitmapToArray(subBitmap(bitmapBuild([1,5,7,9]), toUInt32(1), toUInt64(4)));
+select bitmapToArray(subBitmap(bitmapBuild([1,5,7,9]), toUInt16(1), toUInt32(2)));
+---- Large
+select bitmapToArray(subBitmap(bitmapBuild([
+    0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,
+    100,200,500]), toUInt32(0), toUInt32(10)));
+select bitmapToArray(subBitmap(bitmapBuild([
+    0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,
+    100,200,500]), toUInt32(30), toUInt32(200)));
+select bitmapToArray(subBitmap(bitmapBuild([
+    0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,
+    100,200,500]), toUInt32(34), toUInt16(3)));
+
 -- bitmapMin:
 ---- Empty
 SELECT bitmapMin(bitmapBuild(emptyArrayUInt8()));

tests/queries/0_stateless/01572_kill_window_function.reference

@@ -0,0 +1,3 @@
+Started
+Sent kill request
+Exit 138

tests/queries/0_stateless/01572_kill_window_function.sh

@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CURDIR"/../shell_config.sh
+
+set -e -o pipefail
+
+# Run a test query that takes very long to run.
+query_id="01572_kill_window_function-$CLICKHOUSE_DATABASE"
+$CLICKHOUSE_CLIENT --query_id="$query_id" --query "SELECT count(1048575) OVER (PARTITION BY intDiv(NULL, number) ORDER BY number DESC NULLS FIRST ROWS BETWEEN CURRENT ROW AND 1048575 FOLLOWING) FROM numbers(255, 1048575)" >/dev/null 2>&1 &
+client_pid=$!
+echo Started
+
+# Use one query to both kill the test query and verify that it has started,
+# because if we try to kill it before it starts, the test will fail.
+while [ -z "$($CLICKHOUSE_CLIENT --query "kill query where query_id = '$query_id' and current_database = currentDatabase()")" ]
+do
+    # If we don't yet see the query in the process list, the client should still
+    # be running. The query is very long.
+    kill -0 -- $client_pid
+    sleep 1
+done
+echo Sent kill request
+
+# Wait for the client to terminate.
+client_exit_code=0
+wait $client_pid || client_exit_code=$?
+
+echo "Exit $client_exit_code"
+
+# We have tested for Ctrl+C.
+# The following client flags don't cancel, but should: --max_execution_time,
+# --receive_timeout. Probably needs asynchonous calculation of query limits, as
+# discussed with Nikolay on TG: https://t.me/c/1214350934/21492
+

tests/queries/0_stateless/02003_memory_limit_in_client.expect

@@ -0,0 +1,40 @@
+#!/usr/bin/expect -f
+
+# This is a test for system.warnings. Testing in interactive mode is necessary,
+# as we want to see certain warnings from client
+
+log_user 0
+set timeout 60
+match_max 100000
+
+# A default timeout action is to do nothing, change it to fail
+expect_after {
+    timeout {
+        exit 1
+    }
+}
+
+set basedir [file dirname $argv0]
+spawn bash -c "source $basedir/../shell_config.sh ; \$CLICKHOUSE_CLIENT_BINARY \$CLICKHOUSE_CLIENT_OPT --disable_suggestion --max_memory_usage_in_client=1"
+expect ":) "
+
+send  -- "SELECT arrayMap(x -> range(x), range(number)) FROM numbers(1000)\r"
+expect "Code: 241"
+
+expect ":) "
+
+# Exit.
+send -- "\4"
+expect eof
+
+set basedir [file dirname $argv0]
+spawn bash -c "source $basedir/../shell_config.sh ; \$CLICKHOUSE_CLIENT_BINARY \$CLICKHOUSE_CLIENT_OPT --disable_suggestion --max_memory_usage_in_client=1"
+expect ":) "
+
+send  -- "SELECT * FROM (SELECT * FROM system.numbers LIMIT 600000) as num WHERE num.number=60000\r"
+expect "60000"
+expect ":) "
+
+# Exit.
+send -- "\4"
+expect eof

website/templates/index/success.html

@@ -2,19 +2,9 @@
     <div class="container text-center">
         <h2 id="success-stories" class="display-4">Success stories</h2>
         <div class="row">
-            <div class="col-lg-4 py-3">
-                <a href="https://blog.cloudflare.com/http-analytics-for-6m-requests-per-second-using-clickhouse/" class="text-reset text-decoration-none" rel="external nofollow noreferrer" target="_blank">
-                    <div class="card py-3 dots-lb">
-                        <div class="card-body">
-                            <h4 class="card-title">HTTP and DNS analytics</h4>
-                            <p class="card-text text-muted">by Cloudflare</p>
-                        </div>
-                    </div>
-                </a>
-            </div>
             <div class="col-lg-4 py-3">
                 <a href="docs/en/introduction/history/" class="text-reset text-decoration-none">
-                    <div class="card py-3 dots-cc">
+                    <div class="card py-3 dots-lb">
                         <div class="card-body">
                             <h4 class="card-title">Yandex Metrica</h4>
                             <p class="card-text text-muted">The original usecase</p>
@@ -23,11 +13,21 @@
                 </a>
             </div>
             <div class="col-lg-4 py-3">
-                <a href="https://www.slideshare.net/glebus/using-clickhouse-for-experimentation-104247173" class="text-reset text-decoration-none" rel="external nofollow noreferrer" target="_blank">
+                <a href="https://eng.uber.com/logging/" class="text-reset text-decoration-none" rel="external nofollow noreferrer" target="_blank">
+                    <div class="card py-3 dots-cc">
+                        <div class="card-body">
+                            <h4 class="card-title">Log Platform</h4>
+                            <p class="card-text text-muted">at Uber</p>
+                        </div>
+                    </div>
+                </a>
+            </div>
+            <div class="col-lg-4 py-3">
+                <a href="https://tech.ebayinc.com/engineering/ou-online-analytical-processing/" class="text-reset text-decoration-none" rel="external nofollow noreferrer" target="_blank">
                     <div class="card py-3 dots-rb">
                         <div class="card-body">
-                            <h4 class="card-title">Experimentation</h4>
-                            <p class="card-text text-muted">at Spotify</p>
+                            <h4 class="card-title">Analytical Processing</h4>
+                            <p class="card-text text-muted">at eBay</p>
                         </div>
                     </div>
                 </a>
@@ -35,31 +35,31 @@
         </div>
         <div class="row">
             <div class="col-lg-4 py-3">
-                <a href="https://translate.yandex.com/translate?url=http%3A%2F%2Fwww.jianshu.com%2Fp%2F4c86a2478cca&amp;lang=zh-en" class="text-reset text-decoration-none" rel="external nofollow noreferrer" target="_blank">
+                <a href="https://blog.cloudflare.com/http-analytics-for-6m-requests-per-second-using-clickhouse/" class="text-reset text-decoration-none" rel="external nofollow noreferrer" target="_blank">
                     <div class="card py-3 dots-rb">
                         <div class="card-body">
-                            <h4 class="card-title">OLAP contest victory</h4>
-                            <p class="card-text text-muted">by Analysys</p>
+                            <h4 class="card-title">HTTP and DNS analytics</h4>
+                            <p class="card-text text-muted">at Cloudflare</p>
                         </div>
                     </div>
                 </a>
             </div>
             <div class="col-lg-4 py-3">
-                <a href="https://translate.yandex.com/translate?url=http%3A%2F%2Fsouslecapot.net%2F2018%2F11%2F21%2Fpatrick-chatain-vp-engineering-chez-contentsquare-penser-davantage-amelioration-continue-que-revolution-constante%2F&lang=fr-en" class="text-reset text-decoration-none" rel="external nofollow noreferrer" target="_blank">
+                <a href="https://www.slideshare.net/glebus/using-clickhouse-for-experimentation-104247173" class="text-reset text-decoration-none" rel="external nofollow noreferrer" target="_blank">
                     <div class="card py-3 dots-rhb">
                         <div class="card-body">
-                            <h4 class="card-title">Digital experience analytics</h4>
-                            <p class="card-text text-muted">by ContentSquare</p>
+                            <h4 class="card-title">Experimentation</h4>
+                            <p class="card-text text-muted">at Spotify</p>
                         </div>
                     </div>
                 </a>
             </div>
             <div class="col-lg-4 py-3">
-                <a href="https://translate.yandex.com/translate?url=https%3A%2F%2Ftech.geniee.co.jp%2Fentry%2F2017%2F07%2F20%2F160100" class="text-reset text-decoration-none" rel="external nofollow noreferrer" target="_blank">
+                <a href="https://bigdatadays.ru/wp-content/uploads/2019/10/D2-H3-3_Yakunin-Goihburg.pdf" class="text-reset text-decoration-none" rel="external nofollow noreferrer" target="_blank">
                     <div class="card py-3 dots-lb">
                         <div class="card-body">
-                            <h4 class="card-title">Speeding up Report API</h4>
-                            <p class="card-text text-muted">at Geniee</p>
+                            <h4 class="card-title">Business Intelligence</h4>
+                            <p class="card-text text-muted">at Deutsche Bank</p>
                         </div>
                     </div>
                 </a>