All data in redis is stored in memory and is an in-memory database. It is an open source, high-performance, NOSQL database developed in C language that stores data in key-value pairs.
Main features of redis
1. Advanced data structure
Provides five possible data types for values
Strings, lists, sets, hashes and sorted sets. Operations unique to these data types are provided and have well-documented time complexity (Big O notation).
2. High Performance
Due to its in-memory characteristics, the project maintainers' commitment to keeping complexity to a minimum, and the event-based programming model, Redis has excellent performance in read and write operations. .
3. Lightweight with no dependencies
Written in ANSI C, no external dependencies. Works in all POSIX environments. Windows is not officially supported, but Microsoft offers an experimental version.
4. High availability
Built-in support for asynchronous, non-blocking, master/slave replication to ensure high availability of data. There is a high availability solution called Redis Sentinel that is currently available but is still considered a work in progress.
redis application scenarios
1. Used for caching (ehcache/memcached) - all redis data is placed in memory (in-memory database)
2. Can replace traditional databases in some specific application scenarios - such as social applications
3. In some large systems, some specific functions can be cleverly implemented: session sharing, shopping Che
As long as you have a rich imagination, redis can be used to give you unlimited surprises...
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