• --max-record-length= len 

Skip rows larger than the given length if myisamchk  cannot allocate memory to hold them. 

• --parallel-recover , -p 

Use the same technique as -r  and -n , but create all the keys in parallel, using different threads. This is beta-quality code. Use at your own risk! 

• --quick , -q 

Achieve a faster repair by modifying only the index file, not the data file. You can specify this option twice to force myisamchk  to modify the original data file in case of duplicate keys. 

• --recover , -r 

Do a repair that can fix almost any problem except unique keys that are not unique (which is an extremely unlikely error with MyISAM  tables). If you want to recover a table, this is the option to try first. You should try --safe-recover  only if myisamchk  reports that the table cannot be recovered using --recover . (In the unlikely case that --recover  fails, the data file remains intact.) 

If you have lots of memory, you should increase the value of myisam_sort_buffer_size . 

• --safe-recover , -o 

Do a repair using an old recovery method that reads through all rows in order and updates all index trees based on the rows found. This is an order of magnitude slower than --recover , but can handle a couple of very unlikely cases that --recover  cannot. This recovery method also uses much less disk space than --recover . Normally, you should repair first using --recover , and then with --safe- recover  only if --recover  fails. 

If you have lots of memory, you should increase the value of key_buffer_size . 

• --set-collation= name 

Specify the collation to use for sorting table indexes. The character set name is implied by the first part of the collation name. 

• --sort-recover , -n 

Force myisamchk  to use sorting to resolve the keys even if the temporary files would be very large. 

• --tmpdir= dir_name , -t dir_name 

The path of the directory to be used for storing temporary files. If this is not set, myisamchk  uses the value of the TMPDIR  environment variable. --tmpdir  can be set to a list of directory paths that are used successively in round-robin fashion for creating temporary files. The separator character between directory names is the colon ( : ) on Unix and the semicolon ( ; ) on Windows. 

## 4.6.4.4 Other myisamchk Options 

• --unpack , -u 

Unpack a table that was packed with myisampack . 

myisamchk  supports the following options for actions other than table checks and repairs: 

• --analyze , -a 

