Linux Server Setup: Part 6 - Database Management

Updated: September 10, 2010

Database Management Systems

A server uses a database management system to determine the method of data storage, access, and retrieval. The following are some common database systems. Some require a database server (system service or daemon) to run at all times, in order to function. Others require only the data files themselves.

MySQL is one of the most popular relational database management systems and is open source and cross-platform. All server Linux distributions offer binary packages for MySQL, and there are numerous MySQL graphical frontend tools for the desktop and the web. Ownership of the MySQL trademark has changed hands more than once, and the future of its open source license is uncertain. There are also other forks with similar goals in mind. MySQL is part of the famous LAMP stack, and is used by small and large organizations.

PostgreSQL is an object-relational database management system, which is free and open source. Many Linux distributions distribute binary packages for it, and most dynamic web applications that support MySQL also have support for it. PostgreSQL, like MySQL, has many graphical frontends. It has won numerous awards for its performance and is used by many large websites.

SQLite is an embedded database management system that is housed inside a set of system libraries, rather than a database server. The code for SQLite has been released into the public domain. The SQLite library must be linked into the web application running it, which differs considerably from database servers, which run independent processes. Because it is small and lighter in terms of power required to run it, SQLite is used on mobile platforms and other embedded systems, but not frequently used on web servers.

Cassandra is described by its developers as a "highly-scalable second-generation distributed database." It was originally developed by Facebook and then released as open source in 2008. It is now maintained by Apache developers. Many prominent social media websites, such as Digg, Twitter, and Reddit have recently migrated to Cassandra. It is designed to answer some of the scalability problems large websites had with traditional RDMS.

NoSQL refers to any database that serves as an alternative to the traditional relational databases. Cassandra is the latest headline-making example, while Google's BigTable and Amazon's Dynamo are other popular examples. Because the term is broad and there are far more than a handful of databases in this category, it truly a category for a broad spectrum of non-relational databases, rather than specifically non-SQL.

Oracle Database is a proprietary relational database system produced by Oracle Corporation. Although the license is proprietary, Oracle does distribute a no-cost version on its website called Oracle Database Express Edition. It is available for most major Linux distributions.