Failed to execute the SQL query

select  i.title,  c.title, c.id, i.unread, i.url, i.enclosure, i.author, i.description, c.icon,  unix_timestamp(ifnull(i.pubdate,i.added)) as ts,  i.pubdate is not null as ispubdate, i.id  , null  from  gre__item  i  inner join  gre__channels  c on (c.id = i.cid)  inner join  gre__folders  f on (f.id = c.parent)  where  not(c.mode & 8) and  not(i.unread & 8) and  not(i.unread & 4) and i.unread & 1 and  1=1  order by  ts desc, f.position asc, c.position asc , ts desc, i.id asc limit  0, 75

Error 126: Incorrect key file for table '/tmp/#sql_56f2_2.MYI'; try to repair it