Warning: [mysql error 1] Can't create/write to file '/tmp/#sql_20c_0.MYI' (Errcode: 122)

SELECT
    author,
    id
  FROM piwigo_images AS i
    JOIN piwigo_image_category AS ic ON ic.image_id = i.id
   WHERE  (category_id NOT IN (5))
    AND author IS NOT NULL
  GROUP BY author, id
  ORDER BY author
; in /var/www/vhosts/der-orca.de/httpdocs/include/dblayer/functions_mysqli.inc.php on line 830
Fatal error: Call to a member function fetch_assoc() on a non-object in /var/www/vhosts/der-orca.de/httpdocs/include/dblayer/functions_mysqli.inc.php on line 211