sql优化

原语句：SELECT id, catid, title, keywords, description, inputtime

FROM news
WHERE catid = 5827117610
ORDER BY id DESC LIMIT 1250, 50

优化后：SELECT id, catid, title, keywords, description, inputtime
FROM news
inner join (select id
               from news
              where catid = 5827117610
              ORDER BY id DESC LIMIT 1250, 50) as lim
 using (id);