Redis Introduction

Redis is completely open source, adheres to the BSD protocol, and is a high-performance key-value database.

Redis and other key - The following are the three characteristics of the value caching product:

Redis supports data persistence, which can save memory data to disk, and can be loaded and used again when restarted.
Redis not only supports simple key-value type data, and also provides list, set, zset, hash and other data structure storage.
Redis supports data backup, that is, master-data backup in slave mode.

Redis Advantages

Performance is extremely high - Redis can read at a speed of110000 times/s, the writing speed is81000 times/s.
Rich data types - Redis supports binary case Strings, Lists, Hashes, Sets, and Ordered Sets data type operations.
Atomic - All operations in Redis are atomic, meaning they either execute successfully or fail to execute at all. Single operations are atomic. Multiple operations also support transactions, i.e., atomicity, by wrapping them with the MULTI and EXEC commands.
Rich features - Redis also supports publish/subscribe, notifications, key expiration, and other features.

Redis has more complex data structures and provides atomic operations for them, which is a different evolutionary path from other databases. Redis data types are all based on basic data structures while being transparent to programmers, without the need for additional abstraction.
Redis runs in memory but can be persisted to disk, so when performing high-speed read and write operations on different datasets, memory needs to be balanced because the data volume cannot exceed the hardware memory. Another advantage of in-memory databases is that, compared to the same complex data structures on disk, operations in memory are very simple, allowing Redis to do many things with strong internal complexity. At the same time, they are compactly generated in an append-only manner because they do not require random access.