Redis Introduction
Redis is completely free open source, BSD comply with the agreement, it is a high-performance key-value database.
Redis and other key - value caching product has the following three characteristics:
- Redis supports data persistence, data in memory can be saved to disk, reboot to load when you can be reused.
- Redis only supports simple key-value data types, while also providing a storage list, set, zset, hash and other data structures.
- Redis supports backup data, i.e., data backup master-slave mode.
redis features
Efficiency : speed reading is 110,000 times Redis / s, write speed is 81000 times / s
Atomicity : All operations are atomic Redis, while Redis also supports the full implementation of atomic and several operations.
It supports a variety of data structures: String (String); List (list); the hash (hash), set (set); zset (ordered set)
Stability : persistence, master-slave replication (cluster)
Other features: support expiration time, support services, message subscription.
Redis and other key-value store What is the difference?
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Redis has a more complex data structure and provide atomic operations on them, which is different from the other databases evolutionary path. Meanwhile Redis data types are based on the basic data structure transparent to the programmer, without the need for additional abstraction.
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Redis running in memory, but can be persisted to disk, so that when the high-speed read and write memory tradeoffs different data sets because the data can not be greater than the amount of hardware memory. Another advantage of in-memory databases are, compared to the same complex data structures, operate in a very simple memory on the disk, so you can do a lot of internal Redis highly complex matter. Meanwhile, in terms of their compact disk format to generate additional way, because they do not require random access.
