Fix ‘Unsupported Extension used for Table’ Error in MySQL

In order to avail new and improved features and functionalities, upgrading to newer version of application and system is opted by users, likewise is the case for MySQL database. So as to have enhanced privileges, upgradation of MySql tables is done, which is usually referred to as mysql_upgrade. Along with the advantage of addition of several function, it sometimes do lead to loss of data from the tables on whole or partially. So, if backup is in place data restore task could be carried in easy manner. Unavailability of backup or failed database restoration attempt using backup and alike arouses the need to fix corrupt table structure using MySql database repair software for the purpose.

Taking instance of a particular upgradation in which, sql database rev 4.0.13 is upgraded to 4.0.14 and after the process completes successfully, some or all of the tables may be found to be damaged and inaccessible. This become more known with generation of errors unsupported extension used for table, when trying to open tables

“E-systemusr/local/mysql/bin#. /myisamchk –a


Myisamchk: error: 138 when opening MyISAM-table



This leads to inaccessibility of data saved in MySql tables, which is the result of either improper upgradation or crop up of such other errors at the time of upgradation that interrupts the process.

For resolving the unsupported extension error and fixing the encountered error, corruption of the table is to be repaired first of all, following the described steps

  • Use check table tablename command for detecting and correcting issue
  • Now execute repair table tablename for the error to be repaired
  • Alternatively, use REPAIR table Tablename USE_FRM, it may not help as it finds the tables empty

If all these methods are found incapable of resolving the issue, MySql repair software is to be used for resolving the associated corruption cause and allows usual access to database tables and records, with the data restored on efficiently to it. It does systematic analysis and scanning of the damaged database so as to resolve all or any howsoever severe sort of corruption it may be.