What is redis? Why redis?
redis is a high-performance key-value database, it is completely open source free, and redis NOSQL is a type of database, database solutions in order to solve a series of problems of high concurrency, high scalability, and large data storage generated, It is a non-relational database. However, it is not a substitute for a relational database, only as an extension under certain circumstances.
redis database is structured in a key-value store of the server, which supports the type of data structure comprising: a string (String), lists (Lists), a hash table (the hash), set (SET), an ordered set (zset )Wait. In order to ensure the efficiency of reading, redis data objects are stored in the memory of them, it can support periodic updates of the data is written to a disk file. But it also provides the intersection and union, as well as a number of different ways of sorting operation.
redis advantages and characteristics?
. 1, redis very fast read and write data, the data as it is read into memory operation, and redis is written in C language, is the "closest", "the language of the operating system, the execution speed is relatively fast.
2, redis although data are read in memory of them, but ultimately it is persisted to disk data to support them.
3, redis provides a rich data structure.
4, redis all operations are atomic, transactional, so-called atomic changes to the data that is either all executed or not executed all.
5, redis support replication from the master, the host will automatically synchronize data to the slave, separate read and write may be performed.