SQL to check the disk usage of the database / table, kill the process and terminate the connection in tidb

1、 view the database / Table disk usage

--  Check the memory usage of the entire library ：
select concat(truncate(sum(data_length)/1024/1024,2),'MB') as data_size,
          concat(truncate(sum(index_length)/1024/1024,2),'MB') as index_size
  from information_schema.tables
where TABLE_SCHEMA = 'tablename';

--  The memory occupation of the query table ：
select concat(truncate(sum(data_length)/1024/1024,2),'MB') as data_size,
          concat(truncate(sum(index_length)/1024/1024,2),'MB') as index_size
  from information_schema.tables
where TABLE_NAME = 'tablesname';

• TABLE_SCHEMA： The name of the schema to which the table belongs .
  TABLE_NAME： The name of the table .
  DATA_LENGTH： Data length .DATA_LENGTH= TABLE_ROWS * The sum of the storage lengths of the columns in a tuple . Not thinking about TiKV Copy of .
  INDEX_LENGTH： Index length .INDEX_LENGTH= TABLE_ROWS * The sum of the length of the columns in the index tuple . Not thinking about TiKV Copy of .

Reference resources tidb

2、KILL TIDB Statement is used to terminate TiDB Connection in .

SHOW PROCESSLIST;

+------+------+-----------+------+---------+------+-------+------------------+
| Id   | User | Host      | db   | Command | Time | State | Info             |
+------+------+-----------+------+---------+------+-------+------------------+
|    1 | root | 127.0.0.1 | test | Query   |    0 | 2     | SHOW PROCESSLIST |
|    2 | root | 127.0.0.1 |      | Sleep   |    4 | 2     |                  |
+------+------+-----------+------+---------+------+-------+------------------+
2 rows in set (0.00 sec)

KILL TIDB 2;

according to the design ,KILL TIDB Statement default and MySQL Are not compatible . The load balancer is usually followed by multiple TiDB The server , This default incompatibility helps prevent errors in TiDB Terminate connection on server .

mysql Usage method ：

KILL [CONNECTION | QUERY] thread_id

Reference resources tidb Official website