MySQL and MariaDB (note: for brevity, I’ll be referring to “MySQL” from now on, but everything here applies to both and, indeed, these days I use MariaDB exclusively on my own servers) are very popular as database servers, but in my experience are rarely properly configured to take advantage of the server’s resources. While I’m not a database administrator (DBA), as a sysadmin I often have to diagnose performance problems in servers I maintain, and MySQL is a common culprit; it seems that most MySQL DBAs are well-versed in SQL, but the my.cnf configuration file seems to be a mostly unexplored mystery to them: either it’s untouched from the default configuration (which is conservatively set to work on the barest of machines), or they limit the memory usage to some 3% of the server’s available RAM(!) , or else they go in the other direction and try to use more resources than are available.
Redis is an in-memory key-value store known for its flexibility, performance, and wide language support. In this guide, we will demonstrate how to install and configure Redis on an Ubuntu 16.04 server.
MongoDB is a free and open-source NoSQL document database used commonly in modern web applications. This tutorial will help you set up MongoDB on your server for a production application environment.
What is a Database?
A database is a separate application that stores a collection of data. Each database has one or more distinct APIs for creating, accessing, managing, searching and replicating the data it holds.
Other kinds of data stores can also be used, such as files on the file system or large hash tables in memory but data fetching and writing would not be so fast and easy with those type of systems.
Nowadays, we use relational database management systems (RDBMS) to store and manage huge volume of data. This is called relational database because all the data is stored into different tables and relations are established using primary keys or other keys known as Foreign Keys.