mysql - order by rand 的查询问题

Question

$totalrows = 10;

$sql = "SELECT 
 posts.Tags as tags, 
 posts.OwnerUserId as postsid, 
 posts.Id as postid, 
 posts.Body as body, 
 posts.Title as title, 
 users.Id as userid, 
 users.DisplayName as usersname  
FROM posts 
JOIN users ON posts.OwnerUserId = users.Id 
WHERE posts.Title != '' order by rand() asc limit " .  $totalrows;

$r = mysql_query($sql) or die(mysql_error());

有什么加速 php 的建议吗？

Answer 1

请参阅 Bill Karwin 的演示文稿。幻灯片 142 及以后。

http://www.slideshare.net/billkarwin/sql-antipatterns-strike-back