Database error

Invalid SQL: select u.* from blogs_visits v join blogs_users u on u.id = v.user_id where u.rank = 'dj' and v.date > 943308000 group by v.user_id order by count(v.id) desc limit 4 
Error: Can't create/write to file '/var/tmp/#sql_283_0.MYI' (Errcode: 28) 
Error number: 1 
Date: Friday 18th 2019f October 2019 06:37:29 AM
File: http://blogs.prosto.fm/index.php