Redis is an open source, advanced key-value store and a fit-for-purpose solution for building high-performance, scalable web applications.
Redis has three main features that make it superior to other key-value data stores.
l Redis keeps its database completely in memory and only uses disk for persistence
l Compared with other key-value data stores, Redis has a relatively rich set of data types
l Redis can replicate data to any number of slaves.
Redis advantages: fast speed, support for rich data types, atomic operation, multi-utility tools.
Redis and other key-value storage systems: Redis is a different evolutionary route of key-value database systems. Its values can contain more complex data types, and atomic operations can be defined on these data types.
Redis is an in-memory database but is persistent on disk databases and thus represents a different trade-off, in this case achieving very high read and write speeds within the constraints of datasets no larger than memory.
The advantage of an in-memory database is that it is easier to manipulate the storage representation of complex data structures in memory than on-disk data structures.
Redis collection: a unique string unordered collection, the unique value indicates that duplicate data in the key is not allowed in the collection.
Setting up adding, removing and testing the existence of members in Redis.
Redis transactions, which allow a set of commands to be executed in a single step, all commands in the transaction are executed as a single isolated operation and executed in sequence, and a request to another client cannot be issued in the middle of a Redis transaction. Transactions are also atomic. Atomic means either process all commands or none.