PostgreSQL is a powerful, object-relational open-source database system. PostgreSQL runs on all common operating systems, has been ACID-compliant since 2001, and has powerful add-ons such as the PostGIS geodatabase extension. PostgreSQL adheres to the SQL standard and was developed by an open-source community. It also includes a server-client architecture. PostgreSQL can be tested free of charge. For this, PostgreSQL is available for free and is free from licenses.