SQL and NoSQL

First, relational database (RDB)

As a traditional database, relational database supports complete ACID attributes, in which the declarative SQL syntax shields the underlying implementation details, and the relational data model also accords with people's normal thinking logic, so relational database occupies a dominant position in all kinds of applications. Common RDB databases include Mysql,Oracle,Sql server,PgSql,SQLite,Mysql branch MariaDB and so on.

Relational database has many advantages, but its disadvantages are gradually exposed in today's Internet environment, including:

Unable to store data structure

The table structure is fixed and the expansibility is poor.

Poor performance of Istroke O with large amount of data

Full-text retrieval function is weak.

Second, non-relational database (NoSQL)

NoSQL means Not Only SQL, and non-relational databases discard one or more of the ACID attributes, so NoSQL is not a silver bullet, but can only be used as a supplement to relational databases, or suitable for specific business scenarios.

Common NoSQL includes the following categories, which are basically generated to supplement the shortcomings of RDB databases:

Kmurv database: solves the malpractice that RDB database can not store data structure, represented by Redis

Document database: solves the problem of poor expansibility of RDB database table structure, represented by MongoDB

Column database: solved the performance problem of RDB database in big data scenario, represented by HBase

Full-text search engine: complements the full-text retrieval capability of RDB database, represented by ES

Third, distributed storage system (DRDB)

For observation, official website

Fourth, the historical track of NoSQL

To borrow a picture on the Internet,

Now it's time to add New SQL.