Small ants Learn Redis notes (1)--redis Introduction, application scenario, Comparison

Nosql = not only SQL anti-SQL motion, non-relational database

NoSQL is stored in the form of Key-value, and contrasts with traditional relational databases.

NoSQL has the following features: non-relational, distributed, open-source, level-scalable.

Advantages:

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

Scenarios for NoSQL:

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

PS: Good extensibility is mainly manifested in the absence of a fixed table structure.

Introduction to Redis:

An open source, in key-value storage, is often called a data structure server. Keys can contain strings, hashes, linked lists, collections, and ordered collections.

The largest user of Redis is Sina Weibo, and its deployment scenario is broadly divided into two categories:

1. The application accesses the Redis database directly.

2. The application accesses Redis directly and only accesses MySQL if the Redis access fails.

Redis Application Scenarios:

1. Take out the latest N data operation

2. Leaderboard application, remove top n operation

3. Applications that need to set the expiration time accurately

4. Counter Application

5. Uniq operation, get a period of time all data exclude duplicate values

6. Real-time system, anti-spam system

7. Pub/sub build the real-time messaging system. Redis exclusive features, publish/Subscribe

8. Build a queue system

9. Caching

Comparison of Redis, Mysal, Mongo db

Redis Mysql MongoDB

Concept of library                  have                                        has                                             has

Concept of table                  none                                        has                                             Collection

The concept of a field does not have any

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Small ants Learn Redis notes (1)--redis Introduction, application scenario, Comparison