Eighth Chapter key Value database

8.1 What is a key-value database

The simplest NoSQL database for key-value databases.

The value of what is stored is not important, just a block, and the application is responsible for understanding the meaning of the stored data.

Redis can store data structures such as List,set,hash, and support the acquisition of values within a range, such as intersection, and complement sets.

8.2 Key-Value database features

When discussing the characteristics of each NoSQL database, you need to understand consistency , transactions , query characteristics, data structures, and extensibility.

　8.2.1 Consistency

Only actions for a single key are "consistent".

8.2.2 Transactions

8.2.3 Query

Only by the keyword query, if you want to query according to the column, then can not be completed with the database, the application to read out their own values, to determine whether it is the value to query.

8.2.4 Data structure

Does not care for values in key-value pairs.

8.2.5 Scalability

8.3 Applicable cases

8.3.1 Storing session information

8.3.2 User Configuration information

8.3.3 Shopping Cart Data

Bind the contents of the shopping cart to the UserID.

8.4 Non-applicable occasions　

8.4.1 Relationship between data

8.4.2 transactions that contain multiple operations

8.4.3 Querying data

Searches for a keyword based on some of the values in value.

8.4.4 Operation Keyword Collection

　　　　

　　　　

　　

Eighth Chapter key Value database