server层统计
权限问题：
1、所有用户都有访问information_schema下的表权限(但只能看到这些表中用户具有访问权限的对象相对应的数据行)，但只能访问Server层的部分数据字典表. 2、Server层中的部分数据字典表以及InnoDB层的数据字典表需要额外授权才能访问，如果用户权限不足，当查询Server层数据字典表时将不会返回任何数据，或者某个列没有权限访问时，该列返回NULL值。 3、当查询InnoDB数据字典表时将直接拒绝访问(要访问这些表需要有process权限，注意不是select权限) 4、从information_schema中查询相关数据需要的权限也适用于SHOW语句。无论使用哪种查询方式，都必须拥有某个对象的权限才能看到相关的数据。 #################### process和show
所有数据库详情
1 mysql> select * from SCHEMATA; 2 +--------------+--------------------+----------------------------+------------------------+----------+ 3 | CATALOG_NAME | SCHEMA_NAME | DEFAULT_CHARACTER_SET_NAME | DEFAULT_COLLATION_NAME | SQL_PATH | 4 +--------------+--------------------+----------------------------+------------------------+----------+ 5 | def | information_schema | utf8 | utf8_general_ci | NULL | 6 | def | apple | utf8mb4 | utf8mb4_general_ci | NULL | 7 | def | mysql | utf8mb4 | utf8mb4_general_ci | NULL | 8 | def | performance_schema | utf8 | utf8_general_ci | NULL | 9 | def | sys | utf8 | utf8_general_ci | NULL | 10 +--------------+--------------------+----------------------------+------------------------+----------+ 11 5 rows in set (0.05 sec) 12 13 mysql>
tables表：
ser@hostname (information_schema) > desc tables; +-----------------+---------------------+------+-----+---------+-------+ | field | type | null | key | default | extra | +-----------------+---------------------+------+-----+---------+-------+ | table_catalog | varchar(512) | no | | | | | table_schema | varchar(64) | no | | | | 数据库名称 | table_name | varchar(64) | no | | | | 表名称 | table_type | varchar(64) | no | | | | 表类型 | engine | varchar(64) | yes | | null | | 存储引擎 | version | bigint(21) unsigned | yes | | null | | | row_format | varchar(20) | yes | | null | | | table_rows | bigint(21) unsigned | yes | | null | | 行数 | avg_row_length | bigint(21) unsigned | yes | | null | | | data_length | bigint(21) unsigned | yes | | null | | 数据大小 | max_data_length | bigint(21) unsigned | yes | | null | | | index_length | bigint(21) unsigned | yes | | null | | 索引大小 | data_free | bigint(21) unsigned | yes | | null | | | auto_increment | bigint(21) unsigned | yes | | null | | 自增长度 | create_time | datetime | yes | | null | | 创建时间 | update_time | datetime | yes | | null | | 更新时间 | check_time | datetime | yes | | null | | | table_collation | varchar(32) | yes | | null | | | checksum | bigint(21) unsigned | yes | | null | | | create_options | varchar(255) | yes | | null | | | table_comment | varchar(2048) | no | | | | 注释 +-----------------+---------------------+------+-----+---------+-------+ 21 rows in set (0.00 sec)
*************************** 19. row *************************** TABLE_CATALOG: def TABLE_SCHEMA: statistics TABLE_NAME: user_2019_08 TABLE_TYPE: BASE TABLE ENGINE: InnoDB VERSION: 10 ROW_FORMAT: Compressed TABLE_ROWS: 351716565 AVG_ROW_LENGTH: 37 DATA_LENGTH: 13293322240 MAX_DATA_LENGTH: 0 INDEX_LENGTH: 10047455232 DATA_FREE: 3670016 AUTO_INCREMENT: 381762867 CREATE_TIME: 2019-09-10 22:59:33 UPDATE_TIME: NULL CHECK_TIME: NULL TABLE_COLLATION: utf8_general_ci CHECKSUM: NULL CREATE_OPTIONS: row_format=COMPRESSED TABLE_COMMENT: 原来的表已经很大了，新指标做在这张表里
所有存储引擎详情
1 mysql> select * from ENGINES order by ENGINE; 2 +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+ 3 | ENGINE | SUPPORT | COMMENT | TRANSACTIONS | XA | SAVEPOINTS | 4 +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+ 5 | ARCHIVE | YES | Archive storage engine | NO | NO | NO | 6 | BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO | 7 | CSV | YES | CSV storage engine | NO | NO | NO | 8 | FEDERATED | NO | Federated MySQL storage engine | NULL | NULL | NULL | 9 | InnoDB | DEFAULT | Supports transactions, row-level locking, and foreign keys | YES | YES | YES | 10 | MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO | 11 | MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO | 12 | MyISAM | YES | MyISAM storage engine | NO | NO | NO | 13 | PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO | 14 +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+ 15 9 rows in set (0.01 sec) 16 17 mysql>
innodb层
锁、事务
1 mysql> show create table innodb_locksG; 2 *************************** 1. row *************************** 3 Table: INNODB_LOCKS 4 Create Table: CREATE TEMPORARY TABLE `INNODB_LOCKS` ( 5 `lock_id` varchar(81) NOT NULL DEFAULT '', 6 `lock_trx_id` varchar(18) NOT NULL DEFAULT '', 7 `lock_mode` varchar(32) NOT NULL DEFAULT '', 8 `lock_type` varchar(32) NOT NULL DEFAULT '', 9 `lock_table` varchar(1024) NOT NULL DEFAULT '', 10 `lock_index` varchar(1024) DEFAULT NULL, 11 `lock_space` bigint(21) unsigned DEFAULT NULL, 12 `lock_page` bigint(21) unsigned DEFAULT NULL, 13 `lock_rec` bigint(21) unsigned DEFAULT NULL, 14 `lock_data` varchar(8192) DEFAULT NULL 15 ) ENGINE=MEMORY DEFAULT CHARSET=utf8 16 1 row in set (0.00 sec) 17 18 ERROR: 19 No query specified 20 21 mysql>