When you want to import a large MyISAM table from a file and the table has many indexes, this may help you.

1. Create the table properly (with index)
2. Flush table

   $ mysqladmin flush-tables -u a_db_user -p

3. Removes all use of indexes for the table

   $ sudo myisamchk --keys-used=0 -rq /var/lib/mysql/dbName/tblName

4. LOAD DATA LOCAL INFILE. Adjust the parameters corresponding to your csv file.

   $ mysql -u your_user_name -p mysql> use your_db_name; mysql> LOAD DATA LOCAL INFILE 'your_data_file.csv' INTO TABLE `your_tbl_name` FIELDS TERMINATED BY ';' ENCLOSED BY '"' ESCAPED BY '\\' LINES TERMINATED BY '\n' IGNORE 1 LINES;

5. Re-create the indexes

   $ sudo myisamchk --key_buffer_size=1024M --sort_buffer_size=1024M -rq /var/lib/mysql/dbName/tblName

6. Flush table

   $ mysqladmin flush-tables -u a_db_user -p

LOAD DATA example

LOAD DATA LOCAL INFILE '/home/xxx/data.csv'
    INTO TABLE mydb.mytable -- make sure the table name is correct!
    FIELDS TERMINATED BY ';'
        OPTIONALLY ENCLOSED BY '"'
        ESCAPED BY '\\'
    LINES TERMINATED BY '\n'
    (@id, field_a, field_b, @flag, @filetime)
    SET
        id = @id+10000,
        filetime = FROM_UNIXTIME(@filetime),
        flag=IFNULL(@flag,0);   

Refer to mysql.com and syntax for more details.