Table Maintenance Statements If you use the  EXTENDED  option, MySQL creates the index row by row instead of creating one index at a time with sorting. This type of repair is like that done by  myisamchk --safe-recover . The  USE_FRM  option is available for use if the  .MYI  index file is missing or if its header is corrupted. This option tells MySQL not to trust the information in the  .MYI  file header and to re-create it using information from the data dictionary. This kind of repair cannot be done with  myisamchk . Use the  USE_FRM  option  only  if you cannot use regular  REPAIR  modes. Telling the server to ignore the  .MYI  file makes important table metadata stored in the  .MYI  unavailable to the repair process, which can have deleterious consequences: If you use  USE_FRM  for a table that was created by a different version of the MySQL server than the one you are currently running,  REPAIR TABLE  does not attempt to repair the table. In this case, the result set returned by  REPAIR TABLE  contains a line with a  Msg_type  value of  error  and a  Msg_text  value of  Failed repairing incompatible .FRM file . If  USE_FRM  is used,  REPAIR TABLE  does not check the table to see whether an upgrade is required. REPAIR TABLE  returns a result set with the columns shown in the following table. The  REPAIR TABLE  statement might produce many rows of information for each repaired table. The last row has a  Msg_type  value of  status  and  Msg_test  normally should be  OK . For a  MyISAM  table, if you do not get  OK , you should try repairing it with  myisamchk --safe-recover . ( REPAIR TABLE  does not implement all the options of  myisamchk . With  myisamchk --safe-recover , you can also use options that  REPAIR TABLE  does not support, such as  --max-record-length .) REPAIR TABLE  table catches and throws any errors that occur while copying table statistics from the old corrupted file to the newly created file. For example. if the user ID of the owner of the  .MYD  or  .MYI  file is • USE_FRM •The current  AUTO_INCREMENT  value is lost. •The link to deleted records in the table is lost, which means that free space for deleted records remains unoccupied thereafter. •The  .MYI  header indicates whether the table is compressed. If the server ignores this information, it cannot tell that a table is compressed and repair can cause change or loss of table contents. This means that  USE_FRM  should not be used with compressed tables. That should not be necessary, anyway: Compressed tables are read only, so they should not become corrupt. Caution REPAIR TABLE Output Column Value Table The table name Op Always  repair Msg_type status ,  error ,  info ,  note , or  warning Msg_text An informational message 2899