摘要： 原查询：select tid, fid, subject, author, authorid from dz_forum_thread where authorid in (select uid from dz_common_member where groupid in (1, 3, 23)) and dateline > 1395663240 and highlight 40 （用时10s）优化后：select tid, fid, subject, author, authorid from dz_common_member as m, dz_forum_thread as t wh 阅读全文