Quite similar to the other databases, the InnoDB database also gets corrupted very easily due to many unexpected reasons like logical crashing, virus infection, application corruption, operating system corruption and human errors. After corruption data stored in the database becomes completely inaccessible and any attempt was made to fetch data from the database. The inaccessibility of data primarily occurs when the ‘InnoDB background operations’ or ‘select command’ crashes. In fact in some cases the inaccessibility of data can also be cause due to InnoDB roll-forward recovery. In order to recover the database after InnoDB corruption systematically, you need the backup of InnoDB database, in case the backup files are not available or have corrupted then you need to use MySQL Database Repair using InnoDB Force Recovery command.

The repair command will prevent all the background processes from executing and will allow you to dump all tables. The repair command needs to be added to the MySQL section before restarting the server:

[mysqld]
innodb_force_recovery = 4.

This repairing option is pretty safe and only some data from the corrupt page will be lost. The command mentioned above is competent enough to repair the database which is corrupted due to logical corruption. The command will prevent various operations like insertion, deletion and updation of files to the corrupted InnoDB database. But if the value is changed to 6 then the database pages are left in obsolete stat and it will result into the more corruption of the MySQL database structure.

[mysql]
innodb_force_recovery = 6

So, to prevent data loss after using above command, it is always advisable that you restore the database from the updated backup. But if the updated backup is not available or has corrupted some how, then you are not left with any other option, other than using any advanced MySQL Repair third-party tool. This tool is incorporated with advanced repair technique that has created in InnoDB database engine and easy to use software to make its handling easy.