Configuration Check · · · · · · · · · · · · · · · · · · · · · 99 4.2.1 Mount the data disk ext4 filesystem with options on the target ma- chines that deploy TiKV· · · · · · · · · · · · · · · · · · · · · 1 Mount the data disk ext4 filesystem with options on the target machines that deploy TiKV For production deployments, it is recommended to use NVMe SSD of EXT4 filesystem to store TiKV data. This configuration using the root user account. Format your data disks to the ext4 filesystem and add the nodelalloc and noatime mount options to the filesystem. It is required to add the nodelalloc option, or else the TiUP

Configuration Check · · · · · · · · · · · · · · · · · · · · · 119 4.2.1 Mount the data disk ext4 filesystem with options on the target ma- chines that deploy TiKV· · · · · · · · · · · · · · · · · · · · · 1 Mount the data disk ext4 filesystem with options on the target machines that deploy TiKV For production deployments, it is recommended to use NVMe SSD of EXT4 filesystem to store TiKV data. This configuration using the root user account. Format your data disks to the ext4 filesystem and add the nodelalloc and noatime mount options to the filesystem. It is required to add the nodelalloc option, or else the TiUP

Configuration Check · · · · · · · · · · · · · · · · · · · · · 107 4.2.1 Mount the data disk ext4 filesystem with options on the target ma- chines that deploy TiKV· · · · · · · · · · · · · · · · · · · · · 1 Mount the data disk ext4 filesystem with options on the target machines that deploy TiKV For production deployments, it is recommended to use NVMe SSD of EXT4 filesystem to store TiKV data. This configuration using the root user account. Format your data disks to the ext4 filesystem and add the nodelalloc and noatime mount options to the filesystem. It is required to add the nodelalloc option, or else the TiUP

Engine void MaterializeMetadata::transaction(const MySQLReplication::Position & position, const std::function & fun) { String persistent_tmp_path = persistent_path + ".tmp"; { out); out.next(); out.sync(); out.close(); } commitMetadata(std::move(fun), persistent_tmp_path, persistent_path); } Select history data MaterializeMySQL Database iterator->second, query_context, database_name, comment); /// create table. auto out = std::make_shared(getTableOutput(database_name, table_name, query_context));

медленные за счет дополнительных фетчей из памяти Метод цепочек 13 13 Метод цепочек 14 14 Пример: std::unordered_map 1. Стабильность указателей на ключ, значение 2. Возможность хранить большие объекты Хеш-таблица Время ClickHouse HashMap 7.366 сек. Google DenseMap 10.089 сек. Abseil HashMap 9.011 сек. std::unordered_map 44.758 сек. Бенчмарки 28 28 perf stat -e cache-misses:u ./integer_hash_tables_and_hashes Cache misses ClickHouse HashMap 329,664,616 Google DenseMap 383,350,820 Abseil HashMap 415,869,669 std::unordered_map 1,939,811,017 Бенчмарки 29 29 http://norvig.com/21-days.html#answers Бенчмарки

Configuration Check · · · · · · · · · · · · · · · · · · · · · 123 4.2.1 Mount the data disk ext4 filesystem with options on the target ma- chines that deploy TiKV· · · · · · · · · · · · · · · · · · · · · 1 Mount the data disk ext4 filesystem with options on the target machines that deploy TiKV For production deployments, it is recommended to use NVMe SSD of EXT4 filesystem to store TiKV data. This configuration using the root user account. Format your data disks to the ext4 filesystem and add the nodelalloc and noatime mount options to the filesystem. It is required to add the nodelalloc option, or else the TiUP

Configuration Check · · · · · · · · · · · · · · · · · · · · · 551 5.2.1 Mount the data disk ext4 filesystem with options on the target ma- chines that deploy TiKV· · · · · · · · · · · · · · · · · · · · · 1 Mount the data disk ext4 filesystem with options on the target machines that deploy TiKV For production deployments, it is recommended to use NVMe SSD of EXT4 filesystem to store TiKV data. This configuration using the root user account. Format your data disks to the ext4 filesystem and add the nodelalloc and noatime mount options to the filesystem. It is required to add the nodelalloc option, or else the TiUP

Configuration Check · · · · · · · · · · · · · · · · · · · · · 617 5.2.1 Mount the data disk ext4 filesystem with options on the target ma- chines that deploy TiKV· · · · · · · · · · · · · · · · · · · · · 1 Mount the data disk ext4 filesystem with options on the target machines that deploy TiKV For production deployments, it is recommended to use NVMe SSD of EXT4 filesystem to store TiKV data. This configuration using the root user account. Format your data disks to the ext4 filesystem and add the nodelalloc and noatime mount options to the filesystem. It is required to add the nodelalloc option, or else the TiUP

26 Going Further Begin Content Area = 16,30 27 Inline C++ in SQL SELECT udsf(' std::string udsf(std::string s) { return "hello, " + s; } ', 'world') • Compiled and linked

Configuration Check · · · · · · · · · · · · · · · · · · · · · 635 5.2.1 Mount the data disk ext4 filesystem with options on the target ma- chines that deploy TiKV· · · · · · · · · · · · · · · · · · · · · 1 Mount the data disk ext4 filesystem with options on the target machines that deploy TiKV For production deployments, it is recommended to use NVMe SSD of EXT4 filesystem to store TiKV data. This configuration using the root user account. Format your data disks to the ext4 filesystem and add the nodelalloc and noatime mount options to the filesystem. It is required to add the nodelalloc option, or else the TiUP