What is "ingres"

Ingres Database is a commercially supported, open-source SQL relational database management system intended to support large commercial and government applications. Ingres Database is fully open source with a global community of contributors. However, Actian Corporation controls the development of Ingres and makes certified binaries available for download, as well as providing worldwide support.

Ingres began as a research project at the University of California, Berkeley, starting in the early 1970s and ending in 1985. The original code, like that from other projects at Berkeley, was available at minimal cost under a version of the BSD license. Ingres spawned a number of commercial database applications, including Sybase, Microsoft SQL Server, NonStop SQL and a number of others. Postgres (Post Ingres), a project which started in the mid-1980s, later evolved into PostgreSQL. It is ACID compatible and is fully transactional (including all DDL statements) and is part of the Lisog open-source stack initiative.