Redis Learning (1) Introduction to-nosql

NoSQL (nosql=not only sql), meaning the SQL movement, is a new revolutionary movement of the database, which was first suggested in the early days that the trend is growing to 2009, which refers to the non-relational database , With the rise of Internet Web2.0 Web site, the traditional relational database in dealing with Web2.0 website, especially the super-large-scale and high-concurrency SNS type Web2.0 Pure dynamic website has appeared to be inadequate, exposing a lot of difficult problems to overcome, The non-relational database has been developed very rapidly because of its own characteristics.

NoSQL is stored in key-value form, unlike traditional relational databases, and does not necessarily follow some of the basic requirements of traditional databases, such as adherence to SQL Standards ,ACID Properties , Table structure , and so on, this kind of database mainly has the following characteristics: non-relational, distributed, open-source, level extensible.

NoSQL Features
1. Handling ultra-large amounts of data
2. Run on a cheap PC server cluster
3. Smash Performance Bottlenecks

NoSQL Application Scenarios
1. High concurrency for data read and write
2. Efficient storage and access to massive amounts of data
3. High scalability and high availability of data

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NoSQL representative for Redis introduction

Website Introduction:

Redis is a open source, BSD licensed, Advanced Key-value cache and store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets, sorted SE TS, bitmaps and hyperloglogs.

It doesn't matter if you can't read (Hee ^_^)

Redis is an open source, BSD certificate, Advanced Key-value storage. It is commonly referred to as a data structure server because keys can contain strings, hashes, linked lists, collections, ordered collections, bitmaps, and counters.

Redis is a key-value storage system. It supports a large number of stored value types, including string (string) list (linked list), set (set), Zset (ordered collection), which support Push/pop, Add/remove, and fetch intersection and set and richer operations, Redis supports a variety of different ways of ordering, in order to ensure efficiency, the data is cached in memory it can also periodically write updated data to disk or write modifications to the appended log file

Sina is the world's largest Redis user

Usage One: The application accesses the Redis server directly

Usage Two: The application accesses Redis directly and only accesses MySQL if Redis access fails

Redis Application Scenarios:
1. Take the latest N data operation
2. Leaderboard application, Top n operation
3. Applications that need to set the expiration time accurately
4. Counter Application
5.Uniq operation to get all data rows for a certain period of time
6. Real-time system, anti-spam system
7.pub/sub Building a real-time messaging system
8. Build a queue system
9. Caching

Redis MySQL and MongoDB differences

Redis and MongoDB have no fields, MySQL has

MongoDB is a collection, MySQL table, Redis no

Redis Learning (1) Introduction to-nosql