in SELECT … FINAL The improvements in TiDB v6.2 PageStorage before 6.2 V1 V2 PageStorage in 6.2 V3 PageStorage in 6.2 In a typical HTAP workload, • AP QPS improves 30% • Peak CPU usage decreases

那么需 要手动加上 CAST转换 : CAST(.. AS UNSIGNED) ： 1. mysql> SELECT @v1, @v2, @v3; 2. +------+------+------+ 3. | @v1 | @v2 | @v3 | 4. +------+------+------+ 5. | A | 65 | 65 | 6. +------+------+------+ 14. 15. mysql> SET @v3 = CAST(b'1000001' AS UNSIGNED); 16. Query OK, 0 rows affected (0.00 sec) 用户自定义变量 用户变量 - 80 - 本文档使用 书栈(BookStack.CN) 构建 17. 18. mysql> SELECT @v1, @v2, @v3; 19. +------+------+------+ +------+------+------+ 20. | @v1 | @v2 | @v3 | 21. +------+------+------+ 22. | A | 65 | 65 | 23. +------+------+------+ 24. 1 row in set (0.00 sec) 如果获取一个没有设置过的变量，会返回一个 NULL： 1. mysql> select @not_exist; 2

8.1.4.2 From v5.x or v6.0 to v6.2 In TiDB v6.2, TiFlash upgrades its data storage format to the V3 version. Therefore, when you upgrade TiFlash from v5.x or v6.0 to v6.2, besides functional changes functional change in PageStorage. 8.1.4.2.1 PageStorage By default, TiFlash v6.2.0 uses PageStorage V3 version format_version = 4. This new data format significantly reduces the peak write I/O traffic. excessive CPU usage caused by TiFlash data GC. Meanwhile, compared with the earlier storage format, the V3 version significantly reduces space amplification and resource consumption. • After an upgrade to

8.1.4.3 From v5.x or v6.0 to v6.2 In TiDB v6.2, TiFlash upgrades its data storage format to the V3 version. Therefore, when you upgrade TiFlash from v5.x or v6.0 to v6.2, besides functional changes functional change in PageStorage. 8.1.4.3.1 PageStorage By default, TiFlash v6.2.0 uses PageStorage V3 version format_version = 4. This new data format significantly reduces the peak write I/O traffic. excessive CPU usage caused by TiFlash data GC. Meanwhile, compared with the earlier storage format, the V3 version significantly reduces space amplification and resource consumption. • After an upgrade to

8.2.4.3 From v5.x or v6.0 to v6.2 In TiDB v6.2, TiFlash upgrades its data storage format to the V3 version. Therefore, when you upgrade TiFlash from v5.x or v6.0 to v6.2, besides functional changes functional change in PageStorage. 8.2.4.3.1 PageStorage By default, TiFlash v6.2.0 uses PageStorage V3 version format_version = 4. This new data format significantly reduces the peak write I/O traffic. excessive CPU usage caused by TiFlash data GC. Meanwhile, compared with the earlier storage format, the V3 version significantly reduces space amplification and resource consumption. • After an upgrade to

8.2.4.3 From v5.x or v6.0 to v6.2 In TiDB v6.2, TiFlash upgrades its data storage format to the V3 version. Therefore, when you upgrade TiFlash from v5.x or v6.0 to v6.2, besides functional changes functional change in PageStorage. 8.2.4.3.1 PageStorage By default, TiFlash v6.2.0 uses PageStorage V3 version format_version = 4. This new data format significantly reduces the peak write I/O traffic. excessive CPU usage caused by TiFlash data GC. Meanwhile, compared with the earlier storage format, the V3 version significantly reduces space amplification and resource consumption. • After an upgrade to

8.2.4.3 From v5.x or v6.0 to v6.2 In TiDB v6.2, TiFlash upgrades its data storage format to the V3 version. Therefore, when you upgrade TiFlash from v5.x or v6.0 to v6.2, besides functional changes functional change in PageStorage. 8.2.4.3.1 PageStorage By default, TiFlash v6.2.0 uses PageStorage V3 version format_version = 4. This new data format significantly reduces the peak write I/O traffic. excessive CPU usage caused by TiFlash data GC. Meanwhile, compared with the earlier storage format, the V3 version significantly reduces space amplification and resource consumption. • After an upgrade to

8.2.4.3 From v5.x or v6.0 to v6.2 In TiDB v6.2, TiFlash upgrades its data storage format to the V3 version. Therefore, when you upgrade TiFlash from v5.x or v6.0 to v6.2, besides functional changes functional change in PageStorage. 8.2.4.3.1 PageStorage By default, TiFlash v6.2.0 uses PageStorage V3 version format_version = 4. This new data format significantly reduces the peak write I/O traffic. excessive CPU usage caused by TiFlash data GC. Meanwhile, compared with the earlier storage format, the V3 version significantly reduces space amplification and resource consumption. • After an upgrade to

840 8.1.4.3 From v5.x or v6.0 to v6.2 In TiDB v6.2, TiFlash upgrades its data storage format to the V3 version. Therefore, when you upgrade TiFlash from v5.x or v6.0 to v6.2, besides functional changes functional change in PageStorage. 8.1.4.3.1 PageStorage By default, TiFlash v6.2.0 uses PageStorage V3 version format_version = 4. This new data format significantly reduces the peak write I/O traffic. excessive CPU usage caused by TiFlash data GC. Meanwhile, compared with the earlier storage format, the V3 version significantly reduces space amplification and resource consumption. • After an upgrade to

868 8.1.4.3 From v5.x or v6.0 to v6.2 In TiDB v6.2, TiFlash upgrades its data storage format to the V3 version. Therefore, when you upgrade TiFlash from v5.x or v6.0 to v6.2, besides functional changes functional change in PageStorage. 8.1.4.3.1 PageStorage By default, TiFlash v6.2.0 uses PageStorage V3 version format_version = 4. This new data format significantly reduces the peak write I/O traffic. excessive CPU usage caused by TiFlash data GC. Meanwhile, compared with the earlier storage format, the V3 version significantly reduces space amplification and resource consumption. • After an upgrade to