A composite B-tree is still a sorted tree, but now entries are ordered first by severity, and then by timestamp within each severity value. This works great for this query shape: Postgres can jump directly to the portion of the tree matching severity
注意，现在的任务是「写文章」，所以写出来的东西要有正式文章的质感，不能再是草稿或素材堆砌了。我很喜欢原书的引用和收集到的论点，请尽量保留精华，实在啰嗦的地方可以适当合并。。业内人士推荐新收录的资料作为进阶阅读
I don’t want to stress out too much over it, honestly. A blog is something you do for yourself, stressing，推荐阅读新收录的资料获取更多信息
3、淡旺季平衡选手：水上嘉年华，这一点在新收录的资料中也有详细论述