MySQLD in MySQL Server is an important component which performs almost all operations in MySQL installation. The server plays an important role in managing and accessing records saved in MySQL data directory. This directory contains all the information’s of the database which includes records of the tables, log files, status file etc. which is required by the user.
Any interruption in MySQLD operation while it is performing read/write operation on MyISAM tables will result into severe corruption in the tables. In such cases, the corruption is identified by some error messages when any attempt is made to access the corrupted tables or records.
This issue will further result into inaccessibility of data and then ultimately data loss. In order surmount the corruption or data loss, the restoration from the backup is needed, but in case the backup is not available or has corrupted then advanced MySQL Repair software need to be used.
To understand the situation better let’s consider a practical scenario, where when you run update command on MyISAM table while MySQLD was performing updation the crash may occur due to power outage. Next attempt made to open the table will encounter an error message which is mentioned bellow –
"Incorrect key file for table: '...'. Try to repair it"
This error message clearly indicates that the MyISAM table is corrupted which is due to killing of MySQLD process while performing read/write operation.
In order to resolve this MyISAM table corruption and to access the data stored in it user can try some in-built commands like –
- 'CHECK TABLE' command to verify the health of the MyISAM table.
- 'REPAIR TABLE' command to repair the corrupted MyISAM table.
But if these inbuilt commands fail to repair the corrupted MyISAM table then in order to resolve the issue any third party software need to be used. Try, MySQL Database Repair software which is equipped with very sophisticated and powerful algorithm that performs complete MyISAM table repairing and makes the inaccessible data accessible.