Archive for the ‘MySQL’ Category

TokyuDB live query reports

I’ve just started to have a peek at TokuDB for MySQL today. I’m running a few statements to turn some existing MyISAM tables over to the TokuDB storage engine. Here’s what you see with a SHOW PROCESSLIST command. Id: 6 User: root Host: localhost:42944 db: test_db Command: Query Time: 658 State: Loading of data about […]

MySQL Partitioning & OPTIMIZE TABLE

MySQL table Partitioning can be used in various way to improve performance. I wanted to get some idea of how this would affect database maintenance operations like OPTIMIZE TABLE. For these tests I used a default install of MySQL 5.6.15, with a key_buffer_size of 2GB, and executed OPTIMIZE TABLE table_name after a series of actions […]

[Warning] User entry ‘username’@’hostname’ has an empty plugin value. The user will be ignored and no one can login with this user anymore.

After upgrading an instance of MySQL to 5.7 I was unable to login and had several of the following entries in the error log. [Warning] User entry ‘username’@’hostname’ has an empty plugin value. The user will be ignored and no one can login with this user anymore. This is explained the the release notes. Here’s […]

ERROR Failed to open the relay log ‘7’ (relay_log_pos 0)

I received the following error when I upgraded modified a slave from MySQL 5.6.14 to MariaDB 5.5.33 and executing “START SLAVE;”. 131106 11:12:31 [ERROR] Failed to open the relay log ‘7’ (relay_log_pos 0) I checked my relay-log.info file and it looked like below… 7 /logs/relay/hostname-relaylog.000046 661930553 hostname-masterlog.000019 661930383 0 0 0 Obviously there a difference […]

Native table ‘performance_schema’.’threads’ has the wrong structure

After upgrading a MySQL slave from 5.5 to 5.6.14 I attempted to execute the following query… ?View Code MYSQLSELECT * FROM performance_schema.threads; Despite the error log not reporting any issues I received the following error… Native table ‘performance_schema’.’threads’ has the wrong structure This was simply resolved by executing… ?View Code BASHmysql_upgrade -h localhost -u root […]