MySQL Tipps und Tricks
From Lolly's Wiki
Oneliner
All grants
# mysql --skip-column-names --batch --execute 'select concat_ws("@",user,host) from mysql.user' | xargs -n 1 -i mysql --execute 'show grants for {}'
InnoDB space
Per database
mysql> select table_schema as database_name, sum(round(data_length/1024/1024,2)) as total_size_mb from information_schema.tables where engine like 'innodb' group by table_schema order by total_size_mb;
Per table
mysql> select table_schema as database_name,table_name,round(data_length/1024/1024,2) as size_mb from information_schema.tables order by size_mb;
Logging
Enable/disable general logging
mysql> SET GLOBAL general_log_file = '/var/lib/mysql/general.log';
Query OK, 0 rows affected (0.00 sec)
mysql> SET GLOBAL general_log = 'ON';
Query OK, 0 rows affected (0.00 sec)
mysql> SET GLOBAL general_log = 'OFF';
Query OK, 0 rows affected (0.00 sec)
Enable/disable general logging
mysql> SET GLOBAL slow_query_log_file = '/var/lib/mysql/general.log';
Query OK, 0 rows affected (0.00 sec)
mysql> SET GLOBAL slow_query_log = 'ON';
Query OK, 0 rows affected (0.00 sec)
mysql> SET GLOBAL slow_query_log = 'OFF';
Query OK, 0 rows affected (0.00 sec)