"Lost connection to MySQL server during query" error

Question

I have MySQL 5.5.20 and this table:

mysql> desc country;
+----------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+----------------+-------------+------+-----+---------+-------+
| id | int(255) | NO | PRI | NULL | |
| iso | varchar(2) | NO | | NULL | |
| name | varchar(80) | NO | | NULL | |
| printable_name | varchar(80) | NO | | NULL | |
| iso3 | varchar(3) | YES | | NULL | |
| numcode | smallint(6) | YES | | NULL | |
+----------------+-------------+------+-----+---------+-------+

If I run a query like this

SELECT country.ID, country.ISO, country.NAME,
 country.PRINTABLE_NAME, country.ISO3, country.NUMCODE
FROM country;

It returns:

ERROR 2013 (HY000): Lost connection to MySQL server during query

If I change the order of the columns (ISO3 before PRINTABLE_NAME for example) like this:

SELECT country.ID, country.ISO, country.NAME,
 country.PRINTABLE_NAME, country.NUMCODE, country.ISO3
FROM country;

It works fine!

Or if I rewrite the query using lower-case letters for columns, it works as well.

This issue appears from time to time (about once a month) and the only solution to fix it is to restart MySQL! i have checked error log and nothing added to error log upon this error!! I am really confused and don't know why this happens! Any ideas on how this could be fixed?

• Alaa: yes... but nothing beneficial,,, it says: 130310 11:01:23 [Warning] /usr/sbin/mysqld: Forcing close of thread 401108 user: 'root'
• Mat: (Side note: please capitalize your "I"s. It's always written in uppercase in English, never "i".)
• borrel: maybe a good time to update MySQL as you are hitting bugs with an old version

Answer 1

I am running MySQL 5.7.26 on Windows and when doing just a simple query from the MySQL command line client I get that same error you describing. I found out it only occurs when the query length is exact 64 characters! Just by adding a space fixed the problem for me.
It doesn't matter if it's a select or insert/delete/update query.
I have run 66.000 queries on my server and only the queries with exact 64 characters failed.
I checked the database for corruption. But I could also reproduce same problem when making a new database and table on that server.
I could only reproduce this problem on that production server. I created a new server with same version with exact same settings as a VMWare machine but could not recreate. Used the same MySQL client.