Common open source databases under Linux, how many do you know?

As the name suggests, a database is a place to store data. Its storage space is very large, and it can store millions, tens of thousands, and hundreds of millions of pieces of data. It is the cornerstone to ensure the stable operation of a computer system.SoWhat are the open source databases in Linux? This article will introduce them to you.
1. MySQL
MySQL is an open source relational database management system, a product of Oracle Corporation.It supports multiple storage engines, clusters, full-text indexing, multi-threading, full utilization of CPU resources, multi-user support, and many other very professional functions.
MySQL has become the most popular open source database due to its high performance, low cost and good reliability, and is widely used in web applications and other small and medium-sized projects.Everything from WordPress to Movable Type uses MySQL as the default database.In addition, since Oracle acquired MySQL, it has closed the potential risk of MySQL, so the community adopts the method of branching to avoid this risk, and develops and operates the MariaDB database that is fully compatible with MySQL.
2. MongoDB
MongoDB is an open source, document-oriented and the most popular Nosql database at the moment. It is also a product between relational and non-relational databases.The biggest feature of Mongo is that the query language it supports is very powerful, and its syntax is somewhat similar to an object-oriented query language. It can implement most of the functions similar to single-table query in relational databases, and it also supports indexing of data.It also has the characteristics of high performance, easy deployment, easy use, and convenient data storage.
3. Hadoop
Hadoop is an open source, distributed database based on the column store model.Apache is part of the Hadoop project, and the development language isjava.
Hadoop is different from general relational databases, it is a database suitable for unstructured data storage.Another difference is that Hadoop is column-based rather than row-based.And it is a distributed database with high reliability, high performance, scalability, and based on the relational model.
4. Redis
Redis is an open source, web-enabled, in-memory, key-value store database.Developers can dump entire hashes, lists, sets, and other complex result stores without storing numbers and strings. In addition, Redis provides features such as replication/synchronization and persistence.
Redis is a high-performance key-value database.The emergence of Redis has largely compensated for the insufficiency of key/value storage such as memcached, and can be a good complement to relational databases in some occasions.
5. MariaDB
MariaDB database management system is a fork of MySQL, fully compatible with MySQL, including API and command line, making it an easy replacement for MySQL.In terms of storage engine, XtraDB is used instead of MySQL's InnoDB.Additional functionality has been added to support local non-blocking operations and progress reporting.This means that all connectors, libraries and applications using MySQL will also work under MariaDB.