Redis学习笔记1-Redis的介绍和认识

说明:文章内容来自百度百科和redis官方对redis的介绍

      Redis是一个开源的使用ANSI C语言编写、支持网络、可基于内存亦可持久化的日志型、Key-Value数据库，并提供多种语言的API

redis是一个key-value存储系统。和Memcached类似，它支持存储的value类型相对很多其它，包含string(字符串)、list(链表)、set(集合)、zset(sorted set --有序集合)和hash（哈希类型）。这些数据类型都支持push/pop、add/remove及取交集并集和差集及更丰富的操作，并且这些操作都是原子性的。

在此基础上，redis支持各种不同方式的排序。与memcached一样。为了保证效率，数据都是缓存在内存中。差别的是redis会周期性的把更新的数据写入磁盘或者把改动操作写入追加的记录文件，并且在此基础上实现了master-slave(主从)同步。

Redis 是一个高性能的key-value数据库。 redis的出现。非常大程度补偿了memcached这类key/value存储的不足，在部 分场合能够对关系数据库起到非常好的补充作用。

它提供了Python。Ruby，Erlang，PHPclient，使用非常方便。

Redis支持主从同步。数据能够从主server向随意数量的从server上同步，从server能够是关联其它从server的主server。这使得Redis可运行单层树复制。从盘能够有意无意的对数据进行写操作。因为全然实现了公布/订阅机制，使得从数据库在不论什么地方同步树时，可订阅一个频道并接收主server完整的消息公布记录。同步对读取操作的可扩展性和数据冗余非常有帮助。

官方英文原文介绍Redis

Introduction to Redis

Redis is an open source, BSD licensed, advanced key-value store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets and sorted sets.

You can run atomic operations on these types, like appending to a string; incrementing the value in a hash; pushing to a list; computing set intersection, union and difference; or getting the member with highest ranking in a sorted set.

In order to achieve its outstanding performance, Redis works with an in-memory dataset. Depending on your use case, you can persist it either by dumping the dataset to disk every once in a while, or by appending each command to a log.

Redis also supports trivial-to-setup master-slave replication, with very fast non-blocking first synchronization, auto-reconnection on net split and so forth.

Other features include Transactions, Pub/Sub, Lua scripting, Keys with a limited time-to-live, and configuration settings to make Redis behave like a cache.

You can use Redis from most programming languages out there.

Redis is written in ANSI C and works in most POSIX systems like Linux, *BSD, OS X without external dependencies. Linux and OSX are the two operating systems where Redis is developed and more tested, and we recommend using Linux for deploying. Redis may work in Solaris-derived systems like SmartOS, but the support is best effort. There is no official support for Windows builds, but Microsoft develops and maintains a Win32-64 experimental version of Redis.

学习redis最好的资料就是官方站点的文档http://redis.io/