C++20 ❤ SQL John R Bandela, MDOverview u SQL u C++ Example u Implementation techniques u fixed_string u meta_struct u Parsing compile time strings into meta_structsOverview v SQL v C++ Example {price_from_user};Avoiding SQL Injection Attacks SELECT orders.id, name, item, price, discount_code FROM orders JOIN customers ON customers.id = customerid WHERE price > ?;SQL Library Options u Traditional Lots of information available u Vulnerable to sql injection of developer not careful u Use dynamic typingDomain Specific Language u Use types to encode SQL u Looks more like regular C++ u Typically requires

TiDB 数据库管理 TiDB 服务 TiDB 进程启动参数 TiDB 系统数据库 TiDB 系统变量 TiDB 专用系统变量和语法 TiDB 访问权限管理 TiDB 用户账户管理 使用加密连接 SQL 优化 理解 TiDB 执行计划 统计信息 语言结构 字面值 数据库、表、索引、列和别名 关键字和保留字 用户变量 表达式语法 注释语法 字符集和时区 字符集支持 字符集配置 时区 数据类型 日期和时间类型 日期和时间函数 位函数和操作符 Cast 函数和操作符 加密和压缩函数 信息函数 JSON 函数 GROUP BY 聚合函数 其他函数 精度数学 SQL 语句语法 数据定义语句 (DDL) 数据操作语句 (DML) 事务语句 数据库管理语句 Prepared SQL 语句语法 实用工具语句 JSON 支持 Connectors 和 API TiDB 事务隔离级别 错误码与故障诊断 与 MySQL 兼容性对比 TiDB 进程启动参数 TiDB 数据目录 TiDB 系统数据库 TiDB 系统变量 TiDB 专用系统变量和语法 TiDB 服务器日志文件 TiDB 访问权限管理 TiDB 用户账户管理 使用加密连接 SQL 优化 理解 TiDB 执行计划 统计信息 语言结构 字面值 数据库、表、索引、列和别名 关键字和保留字 用户变量 表达式语法 注释语法 字符集和时区 字符集支持 字符集配置 时区 数据类型 数值类型

设置为 utf8mb4 的效果是否⼀样 Q10: TiDB 加个联合索引会锁表吗 Q11:TiDB默认时区 Q12:查看TiDB创建索引的过程是否已经结束 Q13：TiDB 最⼤连接数 Q14: SQL执⾏时间突然变⻓ Q15: 如何通过tableID 查找表名 Q16: 如何查看当前版本 ⽬录 分布式NewSQL数据库 TiDB Copyright © 2012-2021 UCloud 优刻得 7/120 Hadoop 体系太复杂，运维、存储成本太⾼⽆法满⾜⽤⼾ 的需求。与 Hadoop 相⽐，TiDB 就简单得多，业务通过 ETL ⼯具或者 TiDB 的同步⼯具将数据同步到 TiDB，在 TiDB 中可通过 SQL 直接⽣成报表 真正⾦融级⾼可⽤ 真正⾦融级⾼可⽤ 相⽐于传统主从 (M-S) 复制⽅案，基于 Raft 的多数派选举协议可以提供⾦融级的 100% 数据强⼀致性保证，且在不丢失⼤多数副本的前提下，可以实现故障的⾃动恢复 | root | | time:83.8372ms, loops:2 | funcs:count(1)->Column#4 | 372 Bytes | N/A | | └─TableReader_17 | 1.00 | 1 | root | | time:83.7776ms, loops:2, rpc num: 1, rpc time:83.5701ms, proc keys:0 | data:TableFullScan_16

on CppCon Discord https://aka.ms/cppcon/discord • Meet the Microsoft C++ team • Ask any questions • Discuss the latest announcements Take our survey: https://aka.ms/cppcon/vscodeMicrosoft C++ 1 Check out the recording of: “What’s New in Visual Studio” – David Li & Mryam Girmay Download at aka.ms/vscodeMicrosoft C++ What extensions do you need as a C++ Developer? Recommended Extensions for C++: open-source libraries of any C++ package manager - Bring your own libraries or use these! Learn more at aka.ms/vcpkgMicrosoft C++ GitHub Codespaces Compilers, debuggers & extensions are already installed and

Scalable read Cons: ● Single point write (if you want to scale out writer, you still need sharding) ● SQL layer is not designed for complex query ● Reader is eventual consistency ● Memory size and storage Node TiDB Node TiDB Node Key-Value or Co-processor API calls ... ... ... TiDB servers, stateless, SQL engine PD PD PD MySQL/MariaDB clients, ORMs, JDBC/ODBC, Applications ... MySQL Wire Protocol heartbeat Auto MySQL Compatibility Low High Max Capacity (Good performance) Few TBs 200 TB+ TiDB architecture SQL NoSQL Mapping MySQL wire protocol TiDB Server TiKV Server Storage Physical Stack Highly layered TiKV

Support Those with Large Databases (2TB+ Tables) Those with High Write Rates (Less than 20ms) Already use SQL databases Require high consistency A DATABASE SOLUTION TIDB 4 FEATURES SPEED SCALE Core GUARANTEES ON DATA READS AND WRITES MySQL compatibility for TiDB means existing queries work with this SQL database out of the box, and with little to no need for adaptation. It also means existing tools cluster.) 03 EXPENSIVE IF NOT EXPLOITED Change Data Capture (CDC) tools and processes that rely on the SQL layer, have some issues since TiCDC only receives changes at a higher TiKV level. There are workarounds

conversion. • Timing errors: for example, delivering a result in 1.2ms to a device supposedly responding to an external event in 1ms. • Allocation unpredictability: for example, ban on free store allocation break-ins • Spies (insider attacks) • Spear phishing • Door rattling • Denial of service attacks • SQL injection • Corrupted input/Data • Rule of thumb: always first attack the weakest link Stroustrup conversion. • Timing errors: for example, delivering a result in 1.2ms to a device supposedly responding to an external event in 1ms. • Allocation unpredictability: for example, ban on free store allocation

文件名：src/main.rs 398/562Rust 程序设计语言 简体中文版 fn slow(name: &str, ms: u64) { thread::sleep(Duration::from_millis(ms)); println!("'{name}' ran for {ms}ms"); } 在示例 17-22 中，我们使用 slow 在几个 future 中模拟这类 CPU 密集型工作。首先，每个 如果运行代码，你会看到这些输出： 'a' started. 'a' ran for 30ms 'a' ran for 10ms 'a' ran for 20ms 'b' started. 'b' ran for 75ms 'b' ran for 10ms 'b' ran for 15ms 'b' ran for 350ms 'a' finished. 与上一个示例一样，race 仍然在 a 完成后就立刻结束了。两个 程序设计语言 简体中文版 let one_ms = Duration::from_millis(1); let a = async { println!("'a' started."); slow("a", 30); trpl::sleep(one_ms).await; slow("a"

manages the tree structure with the two fields parent and position using SQL Common Table Expressions (CTE) which allow recursive SQL statements. Consequently all model fields originating with treebeard are and ‘force_update’ parameters can be used to insist that the “save” must be an SQL insert or update (or equivalent for non-SQL backends), respectively. Normally, they should not be set. save_base(*args, and ‘force_update’ parameters can be used to insist that the “save” must be an SQL insert or update (or equivalent for non-SQL backends), respectively. Normally, they should not be set. Admin class cms.extensions

any character whatsoever, even a newline, which normally it would not match. Used together, as r""ms, they let the "." match any character whatsoever, while still allowing "^" and "$" to match, respectively missing object, which is the singleton instance of the type Missing. missing is equivalent to NULL in SQL and NA in R, and behaves like them in most situations. 21.1 Propagation of Missing Values missing This follows the well-established rules of three-valued logic which are implemented by e.g. NULL in SQL and NA in R. This abstract definition corresponds to a relatively natural behavior which is best explained