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• myisamchk  marks tables as checked if you run it with the --update-state  option. myisamchk -- fast  checks only those tables that don’t have this mark. 

• myisamchk --analyze  stores statistics for portions of keys, as well as for entire keys. 

• myisampack  can pack BLOB  and VARCHAR  columns. 

MyISAM  also supports the following features: 

•Support for a true VARCHAR  type; a VARCHAR  column starts with a length stored in one or two bytes. 

•Tables with VARCHAR  columns may have fixed or dynamic row length. 

•The sum of the lengths of the VARCHAR  and CHAR  columns in a table may be up to 64KB. 

## Additional Resources 

•Arbitrary length UNIQUE  constraints. 

•A forum dedicated to the MyISAM  storage engine is available at https://forums.mysql.com/list.php?21. 

## 16.2.1 MyISAM Startup Options 

The following options to mysqld  can be used to change the behavior of MyISAM  tables. For additional information, see Section 5.1.7, “Server Command Options” . 

<img src='content_image/743520.jpg'>

The following system variables affect the behavior of MyISAM  tables. For additional information, see Section 5.1.8, “Server System Variables” . 

• bulk_insert_buffer_size 

