user warning: Incorrect key file for table '/tmp/#sql_a02_2.MYI'; try to repair it query: SELECT n.title AS topictitle, r.title AS replytitle, r.time timestamp, r.type AS replytype, n.type AS topictype, n.nid AS topicid, t.tid, r.cid AS cid, r.uid, u.name FROM node AS n INNER JOIN ( (SELECT title, created AS time, nid, uid, type, 'cid' AS cid FROM node ) UNION (SELECT subject, timestamp, nid, uid, 'comment', cid FROM comments WHERE comments.status = 0 ) ORDER BY time DESC ) AS r ON n.nid=r.nid INNER JOIN term_node AS t ON n.nid = t.nid INNER JOIN users AS u ON r.uid = u.uid WHERE n.status = 1 GROUP BY tid; in /var/www/html/includes/database.mysql.inc on line 172.