The ARCHIVE storage engine is used for storing large amounts of data without indexes in a very small footprint.
When you create an ARCHIVE table, the server creates a table format file in the database directory. The file begins with the table name and has an .frm extension. The storage engine creates other files, all having names beginning with the table name. The data and metadata files have extensions of .ARZ and .ARM, respectively. An .ARN file may appear during optimization operations.
The ARCHIVE engine supports INSERT and SELECT, but not DELETE, REPLACE, or UPDATE. It does support ORDER BY operations, BLOB columns