操作数据库(database) 步骤包括:连接数据库、打开数据库、操作数据、关闭数据库 1.连接数据库 默认为 mysql -u root -p -u 登录用户名,默认root -p 密码,默认无 -h 服务器地址 -P 端口号,一般默认3366 2.打开数据库 use 库名; 3.操作数据库 查看数据库 show databases; 创建数据库 create database 库...
mysql sys database can't select data when use utf8mb4_general_ci,I found that changing the collation rules of sys can solve the problem. Can I rebuild the collation rules of the sys database? What would be the impact if I did this? eg: 1、 $ mysqldump --user=root --default-chara...
由于Azure Database for MySQL 灵活服务器可根据存储缩放 IO,将预配存储增大到 1 TB 后,IO 延迟减小为 571 毫秒。 sys.schema_tables_with_full_table_scans 尽管经过认真规划,但许多查询仍可能导致全表扫描。 有关索引类型以及如何优化索引的详细信息,请参阅此文:使用 EXPLAIN 分析 Azure Database for MySQL ...
方案1:使用mysql_upgrade修复sys库 适用于sys库已经损坏的情况下。 删除sys库: DROPDATABASEsys; 执行mysql_upgrade: mysql_upgrade --upgrade-system-tables --skip-verbose --force 注意:mysql_upgrade在修理sys库的同时,还修理mysql库和用户库表(期间加锁且速度一般),有极小可能会误伤; ...
MySQL 9.2 Reference Manual / MySQL sys Schema / Using the sys Schema 30.2 Using the sys Schema You can make the sys schema the default schema so that references to its objects need not be qualified with the schema name: mysql> USE sys; Database changed mysql> SELECT * FROM version; +...
Bug #113016 sys database can't select when use utf8mb4_general_ci Submitted: 9 Nov 2023 6:22Modified: 9 Nov 2023 11:49 Reporter: chong zhang Email Updates: Status: Duplicate Impact on me: None Category: MySQL Server: SYS SchemaSeverity: S1 (Critical) Version: 8.0.25OS: Any ...
mysql> use sysDatabasechanged mysql> select * from schema_object_overview where db='sys'; +---+---+---+ | db | object_type | count | +---+---+---+ | sys |PROCEDURE|26| | sys |VIEW|100| | sys |BASETABLE|1| | sys |INDEX...
(root@localhost) [sys]>showdatabases;+---+|Database|+---+|information_schema||mysql||performance_schema||sys||ztest|+---+5rowsinset(0.01sec) (root@localhost) [sys]>use sys Database changed (root@localhost) [sys]>showtables;+---+|Tables_in_sys|+...
1 row in set (0.00 sec) mysql> use sys; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed mysql> select * from version; +---+---+ | sys_version | mysql_version |...
2、每个库(database)占用多少 buffer pool 3、统计 innodb 引擎的 innodb 缓存 pages 是指在 buffer pool 中的 page 数量;pages_old 指在 LRU 列表中处于后37%位置的 page。当出现 buffer page 不够用时,就会征用这些 page 所占的空间。37%是默认位置,具体可以自定义。