Database Administration
更新时间：2024-11-25 11:03:09
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在 Database Administration 语法上， RadonDB 与 MySQL 兼容。
CHECKSUM
校验表的数据一致性。
语法
CHECKSUM TABLE [database_name.]table_name示例
mysql> checksum table test.t1;
+----------+------------+
| Table | Checksum |
+----------+------------+
| test.t1 | 2464930879 |
+----------+------------+
1 row in set (0.00 sec)KILL
KILL 某个连接，包含终止连接正在执行的语句。
语法
KILL processlist_id示例
mysql> show processlist;
+------+------+-----------------+------+---------+------+-------+------+-----------+---------------+
| Id | User | Host | db | Command | Time | State | Info | Rows_sent | Rows_examined |
+------+------+-----------------+------+---------+------+-------+------+-----------+---------------+
| 11 | mock | 127.0.0.1:43028 | test | Sleep | 291 | | | 0 | 0 |
+------+------+-----------------+------+---------+------+-------+------+-----------+---------------+
1 row in set (0.00 sec)
mysql> kill 11;
ERROR 2013 (HY000): Lost connection to MySQL server during querySET
-
为了兼容 JDBC/mydumper 。
-
SET 是一个空操作，除了
autocommit 和 radon_streaming_fetch其他操作并不生效，请勿直接使用。
SHOW
SHOW 具有许多形式，可提供有关 database，table，columns 或有关服务器状态的信息。
SHOW CHARSET
该语句列出所有可用的字符集。
语法
SHOW CHARSET示例
mysql> show charset; +----------+---------------------------------+---------------------+--------+ | Charset | Description | Default collation | Maxlen | +----------+---------------------------------+---------------------+--------+ | big5 | Big5 Traditional Chinese | big5_chinese_ci | 2 | | dec8 | DEC West European | dec8_swedish_ci | 1 | | cp850 | DOS West European | cp850_general_ci | 1 | | hp8 | HP West European | hp8_english_ci | 1 | | koi8r | KOI8-R Relcom Russian | koi8r_general_ci | 1 | | latin1 | cp1252 West European | latin1_swedish_ci | 1 | | latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 | | swe7 | 7bit Swedish | swe7_swedish_ci | 1 | ... ... 41 rows in set (0.02 sec)
SHOW COLLATION
该语句列出所有支持的校验字符集。
语法
SHOW COLLATION示例
mysql> SHOW COLLATION; +--------------------------+----------+-----+---------+----------+---------+ | Collation | Charset | Id | Default | Compiled | Sortlen | +--------------------------+----------+-----+---------+----------+---------+ | big5_chinese_ci | big5 | 1 | Yes | Yes | 1 | | big5_bin | big5 | 84 | | Yes | 1 | | dec8_swedish_ci | dec8 | 3 | Yes | Yes | 1 | | dec8_bin | dec8 | 69 | | Yes | 1 | | cp850_general_ci | cp850 | 4 | Yes | Yes | 1 | | cp850_bin | cp850 | 80 | | Yes | 1 | | hp8_english_ci | hp8 | 6 | Yes | Yes | 1 | | hp8_bin | hp8 | 72 | | Yes | 1 | | koi8r_general_ci | koi8r | 7 | Yes | Yes | 1 | ... ... 222 rows in set (0.05 sec)
SHOW ENGINES
后端分区 MySQL 支持的引擎列表。
语法
SHOW ENGINES示例
mysql> SHOW ENGINES;
+--------------------+---------+----------------------------------------------------------------------------+--------------+------+------------+
| Engine | Support | Comment | Transactions | XA | Savepoints |
+--------------------+---------+----------------------------------------------------------------------------+--------------+------+------------+
| MyISAM | YES | MyISAM storage engine | NO | NO | NO |
| MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO |
| InnoDB | DEFAULT | Percona-XtraDB, Supports transactions, row-level locking, and foreign keys | YES | YES | YES |
| BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |
| CSV | YES | CSV storage engine | NO | NO | NO |
| PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO |
| ARCHIVE | YES | Archive storage engine | NO | NO | NO |
| TokuDB | YES | Percona TokuDB Storage Engine with Fractal Tree(tm) Technology | YES | YES | YES |
| FEDERATED | NO | Federated MySQL storage engine | NULL | NULL | NULL |
| MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |
+--------------------+---------+----------------------------------------------------------------------------+--------------+------+------------+
10 rows in set (0.00 sec)SHOW DATABASES
包含系统 DB，比如 mysql，information_schema。
语法
SHOW DATABASES示例
mysql> SHOW DATABASES;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sbtest1 |
| sys |
+--------------------+
5 rows in set (0.00 sec)SHOW TABLES
如果未指定 db_name，则返回当前 DB 下的表。
语法
SHOW [FULL] TABLES
[FROM db_name]
[LIKE 'pattern' | WHERE expr]示例
mysql> SHOW TABLES;
+----------------+
| Tables_in_test |
+----------------+
| t1 |
| t2 |
+----------------+
2 rows in set (0.00 sec)SHOW TABLE STATUS
若未指定 db_name，则返回当前 DB 下的表。
语法
SHOW TABLE STATUS
[FROM db_name]示例
mysql> show table status;
+--------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+-----------------+----------+----------------+---------+
| Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment |
+--------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+-----------------+----------+----------------+---------+
| b | InnoDB | 10 | Dynamic | 6 | 16384 | 16384 | 0 | 0 | 0 | NULL | 2018-12-24 08:26:24 | 2019-01-22 08:31:47 | NULL | utf8_general_ci | NULL | | |
| g | InnoDB | 10 | Dynamic | 1 | 16384 | 16384 | 0 | 0 | 0 | NULL | 2018-12-24 08:26:24 | 2019-02-28 03:20:46 | NULL | utf8_general_ci | NULL | | |
+--------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+---------------------+------------+-----------------+----------+----------------+---------+
2 rows in set (0.08 sec)SHOW COLUMNS
获取表的列定义。
语法
SHOW [FULL] {COLUMNS | FIELDS}
FROM [db_name.]table_name
[LIKE 'pattern' | WHERE expr]示例
mysql> CREATE TABLE T1(A INT, B VARCHAR(10)) PARTITION BY HASH(A);
Query OK, 0 rows affected (0.52 sec)
mysql> SHOW COLUMNS FROM T1;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| A | int(11) | YES | | NULL | |
| B | varchar(10) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.01 sec)SHOW CREATE TABLE
语法
SHOW CREATE TABLE table_name示例
mysql> SHOW CREATE TABLE t1\G;
*************************** 1. row ***************************
Table: t1
Create Table: CREATE TABLE `t1` (
`id` int(11) DEFAULT NULL,
`b` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)SHOW PROCESSLIST
显示的为 client 到 RadonDB 的连接情况，并非后端分区 MySQL。
语法
SHOW PROCESSLIST示例
mysql> SHOW PROCESSLIST;
+------+------+-------------------+------+---------+------+-------+------+-----------+---------------+
| Id | User | Host | db | Command | Time | State | Info | Rows_sent | Rows_examined |
+------+------+-------------------+------+---------+------+-------+------+-----------+---------------+
| 1 | mock | 192.168.0.3:35346 | test | Sleep | 379 | | | 0 | 0 |
+------+------+-------------------+------+---------+------+-------+------+-----------+---------------+
1 row in set (0.00 sec)SHOW VARIABLES
-
为了兼容 JDBC/mydumper 。
-
SHOW VARIABLES命令会发往后端分区 MySQL (随机分区)获取并返回。
语法
SHOW VARIABLES
[LIKE 'pattern' | WHERE expr]USE DATABASE
切换当前分区 的 Database。
语法
USE db_name示例
mysql> use test;
Database changed