Database structure:

+------------------+----------------------+------+-----+---------+-------+
| Field            | Type                 | Null | Key | Default | Extra |
+------------------+----------------------+------+-----+---------+-------+
| agent            | varchar(255)         | YES  |     | NULL    |       |
| bytes_sent       | int(10) unsigned     | YES  |     | NULL    |       |
| child_pid        | smallint(5) unsigned | YES  |     | NULL    |       |
| cookie           | varchar(255)         | YES  |     | NULL    |       |
| request_file     | longtext             | YES  |     | NULL    |       |
| referer          | longtext             | YES  |     | NULL    |       |
| remote_host      | varchar(50)          | YES  |     | NULL    |       |
| remote_logname   | varchar(50)          | YES  |     | NULL    |       |
| remote_user      | varchar(50)          | YES  |     | NULL    |       |
| request_duration | smallint(5) unsigned | YES  |     | NULL    |       |
| request_line     | longtext             | YES  |     | NULL    |       |
| request_method   | varchar(6)           | YES  |     | NULL    |       |
| request_protocol | varchar(10)          | YES  |     | NULL    |       |
| request_time     | varchar(28)          | YES  |     | NULL    |       |
| request_uri      | longtext             | YES  |     | NULL    |       |
| server_port      | smallint(5) unsigned | YES  |     | NULL    |       |
| ssl_cipher       | varchar(25)          | YES  |     | NULL    |       |
| ssl_keysize      | smallint(5) unsigned | YES  |     | NULL    |       |
| ssl_maxkeysize   | smallint(5) unsigned | YES  |     | NULL    |       |
| status           | smallint(5) unsigned | YES  |     | NULL    |       |
| time_stamp       | int(10) unsigned     | YES  |     | NULL    |       |
| virtual_host     | varchar(50)          | YES  |     | NULL    |       |
+------------------+----------------------+------+-----+---------+-------+

alter columns:

alter table access_default modify column request_uri longtext;
alter table access_default modify column request_line longtext;
alter table access_default modify column referer longtext;
alter table access_default modify column request_file longtext;