redis可以存儲多少key？

官方說單例能處理key：2.5億個，參考鏈接:https://Redis.io/topics/faq，以下是原話：

What is the maximum number of keys a single Redis instance can hold? and what the max number of elements in a Hash, List, Set, Sorted Set?

Redis can handle up to 2^32 keys, and was tested in practice to handle at least 250 million keys per instance.

Every hash, list, set, and sorted set, can hold 2^32 elements.

In other words your limit is likely the available memory in your system.

不同的數據類型存儲量會有差異：

原文地址：https://redis.io/topics/data-types

Strings類型：一個String類型的value最大可以存儲512M

Lists類型：list的元素個數最多為2^32-1個，也就是4294967295個。

Sets類型：元素個數最多為2^32-1個，也就是4294967295個。

Hashes類型：鍵值對個數最多為2^32-1個，也就是4294967295個。

Sorted sets類型：跟Sets類型相似。