write hotspot of TiFlash #3900 • TiFlash – Add operators: MOD / %, LIKE – Add string functions: ASCII(), COALESCE(), LENGTH(), POSITION(), TRIM() – Add mathematical functions: CONV(), CRC32(), DEGREES() GIS/GEOMETRY) functions, data types and indexes #6347 62 • Character sets other than utf8, utf8mb4, ascii, latin1 and binary • SYS schema • Optimizer trace • XML Functions • X-Protocol #1109 • Savepoints corresponding option in the MySQL LOAD DATA statement. [mydumper.csv] ### Separator between fields. Must be ASCII characters. It is not �→ recommended to use the default ','. It is recommended to use '\|+\|' �→

transaction #24741 – Fix the issue of writing the wrong prefix index value when the collation is ascii_bin or latin1_bin #24569 – Fix the issue that the ongoing transaction might be interrupted by the GIS/GEOMETRY) functions, data types and indexes #6347 63 • Character sets other than utf8, utf8mb4, ascii, latin1 and binary • SYS schema • Optimizer trace • XML Functions • X-Protocol #1109 • Savepoints represent them in a double-quoted string ("…"). For example, separator = "\u001f" means using the ASCII character 0x1F as separator. Additionally, you can use single-quoted strings ('…') to suppress backslash

GIS/GEOMETRY) functions, data types and indexes #6347 • Character sets other than utf8, utf8mb4, ascii, latin1 and binary • SYS schema • Optimizer trace • XML Functions • X-Protocol #1109 • Savepoints corresponding option in the MySQL LOAD DATA statement. [mydumper.csv] ### Separator between fields. Must be ASCII characters. It is not �→ recommended to use the default ','. It is recommended to use '\|+\|' �→ represent them in a double- quoted string ("…"). For example, separator = "\u001f" means using the ASCII character 0x1F as separator. Additionally, you can use single-quoted strings ('…') to suppress backslash

+--------------------|----------------------|-----------------------|--------+ 5. | ascii | ascii_general_ci | US ASCII | 1 | 6. | binary | binary | Binary 书栈(BookStack.CN) 构建 3. SELECT _utf8'some text'; 转义字符： \0: ASCII NUL (X’00’) 字符 \‘: 单引号 \“: 双引号 \b: 退格符号 \n: 换行符 \r: 回车符 \t: tab 符（制表符） \z: ASCII 26 (Ctrl + Z) \\: 反斜杠 \ \%: \% \: \ 如果要在 string literal 中使用 ACTION ADD (R) ADDDATE ADMIN AFTER ALL (R) ALTER (R) ALWAYS ANALYZE(R) AND (R) ANY AS (R) ASC (R) ASCII AUTO_INCREMENT AVG AVG_ROW_LENGTH BEGIN BETWEEN (R) BIGINT (R) BINARY (R) BINLOG BIT BIT_XOR BLOB

#24716 #24717 – 修复了 point get 的 prepare plan cache 被事务中的 point get 语句不正确使用的问题 #24741 – 修复了当排序规则为 ascii_bin 或 latin1_bin 时，写入错误的前缀索引值的问题 #24569 – 修复了正在执行的事务被 GC worker 中断的问题 #24591) – 修复了当 new-collation 自定义函数 • 外键约束 #18209 • 临时表 #1248 • 全文语法与索引 #1793 • 空间类型的函数（即 GIS/GEOMETRY）、数据类型和索引 #6347 • 非 ascii/latin1/binary/utf8/utf8mb4 的字符集 • SYS schema • MySQL 追踪优化器 • XML 函数 • X-Protocol #1109 • Savepoints LOAD DATA 语句中 都有对应的项目。 [mydumper.csv] ### 字段分隔符，必须为 ASCII 字符。如果数据中可能有逗号， �→ 建议源文件导出时分隔符使用非常见组合字符例如'|+|'。 separator = ',' ### 引用定界符，可以为 ASCII 字符或空字符。 delimiter = '"' ### CSV 文件是否包含表头。 ### 如果为 true，首行将会被跳过。

features 2.2.2.1 SQL • TiDB supports the GBK character set since v5.4.0 Before v5.4.0, TiDB supports ascii, binary, latin1, utf8, and utf8mb4 character sets. To better support Chinese users, TiDB supports (also known as GIS/GEOMETRY) functions, data types and indexes #6347 • Character sets other than ascii, latin1, binary, utf8, utf8mb4, and gbk. • SYS schema • Optimizer trace • XML Functions • X-Protocol such as: • digits (0 to 9) 1344 • letters (a to z, A to Z) • $ • _ • non ASCII characters (U+0080 to U+10FFFF) All other ASCII characters are reserved. Some punctuations have special meanings, as described

(also known as GIS/GEOMETRY) functions, data types and indexes #6347 • Character sets other than ascii, latin1, binary, utf8, utf8mb4, and gbk. • SYS schema • Optimizer trace • XML Functions 88 • X-Protocol character sets: Character Client-side default collation Server-side default collation ascii ascii_general_ci ascii_bin latin1 latin1_swedish_ci latin1_bin utf8mb4 utf8mb4_0900_ai_ci utf8mb4_bin Way Compiled | Sortlen | +--------------------+---------+-----+---------+----------+---------+ | ascii_bin | ascii | 65 | Yes | Yes | 1 | | binary | binary | 63 | Yes | Yes | 1 | | gbk_bin | gbk | 87 | | Yes

869 – 热点调度支持对 TiFlash 的写热点进行调度 #3900 32 • TiFlash – 新增若干运算符的支持：MOD / %, LIKE – 新增若干字符串函数的支持：ASCII(), COALESCE(), LENGTH(), POSITION(), TRIM() – 新增若干数学函数的支持：CONV(), CRC32(), DEGREES(), EXP(), LN() 自定义函数 • 外键约束 #18209 • 临时表 #1248 • 全文语法与索引 #1793 • 空间类型的函数（即 GIS/GEOMETRY）、数据类型和索引 #6347 • 非 ascii/latin1/binary/utf8/utf8mb4 的字符集 • SYS schema • MySQL 追踪优化器 • XML 函数 • X-Protocol #1109 • Savepoints 等取值为字符串的配置项，如果需要设置的字符串中包含特 殊字符，可以通过使用反斜杠 \ 转义的方式进行输入，输入的转义序列必须被包含在一对双引号 " 之间。例 如，设置 separator = "\u001f" 表示使用 ASCII 字符 0X1F 作为字符串定界符。另外，也可以使用单引号字符 串 '...' 禁止对字符进行转义。另外，设置 separator = '\n' 表示使用两个字符 \ + n 作为字符串定界符，而

grant-hot-leader-scheduler #4903 @lhy1024 • TiFlash • Optimize the execution efficiency of LENGTH() and ASCII() functions #9344 @xzhangxian1008 • Reduce the number of threads that TiFlash needs to create when (also known as GIS/GEOMETRY) functions, data types and indexes #6347 • Character sets other than ascii, latin1, binary, utf8, utf8mb4, and gbk. • Optimizer trace • XML Functions • X-Protocol #1109 108 utf8 or utf8mb4, subtasks are split only based on the range of visible ASCII characters. If many primary key values have the same ASCII prefix, it might cause uneven task splitting. • For tables that do

grant-hot-leader-scheduler #4903 @lhy1024 • TiFlash • Optimize the execution efficiency of LENGTH() and ASCII() functions #9344 @xzhangxian1008 • Reduce the number of threads that TiFlash needs to create when (also known as GIS/GEOMETRY) functions, data types and indexes #6347 • Character sets other than ascii, latin1, binary, utf8, utf8mb4, and gbk. • Optimizer trace • XML Functions • X-Protocol #1109 103 utf8 or utf8mb4, subtasks are split only based on the range of visible ASCII characters. If many primary key values have the same ASCII prefix, it might cause uneven task splitting. • For tables that do