LIMIT语句优化
原语句：SELECT * FROM table ORDER BY id DESC LIMIT 190000,10000
优化后：SELECT * FROM table WHERE id < (SELECT MIN(alias.id) FROM (SELECT id FROM table ORDER BY id DESC LIMIT 190000) alias) ORDER BY id DESC LIMIT 10000
原文：http://www.cnblogs.com/leehope/p/4531490.html