您可以在会话中存储任意数量的数据.所有会话都存储在服务器上.您可以达到的唯一限制是脚本一次可以消耗的最大内存，默认情况下为 128MB.

You can store as much data as you like within in sessions. All sessions are stored on the server. The only limits you can reach is the maximum memory a script can consume at one time, which by default is 128MB.

(类似答案:理想的 PHP 会话大小? - 一些有用的评论)

(Similar answers: Ideal PHP Session Size? - some useful comments)