Mastering Flask Web Development - Second Edition

Speed and scale

A common misconception is that the ACID principle makes RDBMSes slow and unable to scale. This is only half true—it is completely possible for an RDBMS to scale. For example, an Oracle database configured by a professional database administrator can handle tens of thousands of complex queries a second. Huge companies, such as Facebook, Twitter, Tumblr, and Yahoo!, are using MySQL to great effect, and PostgreSQL is emerging as a favorite of many programmers because of its speed advantage over MySQL.