PostgreSQL is an Object-Relational Database Management System (ORDBMS) that has been
developed in various forms since 1977. It began as a project named Ingres at the University of California at
Berkeley. Ingres itself was later developed commercially by Relational
Technologies/Ingres Corporation.
In 1986 another team led by Michael Stonebraker from Berkeley continued the development of
the Ingres code to create an object-relational database system called Postgres. In 1996, due to a
new open source effort and the enhanced functionality of the software, Postgres was renamed to
PostgreSQL, after a brief stint as Postgres95. The PostgreSQL project is still under very active
development worldwide from a team of open source developers and contributors.
PostgreSQL is widely considered to be the most advanced open source database system in the
world. It provides many features (which are discussed in more detail in the Section called PostgreSQL Feature Set
") that
are traditionally seen only in enterprise-caliber commercial products.
PostgreSQL is an open source project. Open source by definition means that you can obtain
the source code, use the program, and modify it freely without the confines of proprietary
software. In the database world, open source means that you have honest access to benchmarking
numbers and performance statistics, which companies such as Oracle prohibit. Open source also
means that you are free to modify PostgreSQL to fit your particular needs.
However, there is a misconception that since open source software is free from distribution
restrictions, it is always free of cost to your company. This is not necessarily the case.
It is true that you can, without external cost, download and install open source software, but
there will always be costs associated with the time and energy your company puts into support
and research of the application. As such, if you do not have those resources to spend, there
are several commercial vendors and consultants who deal specifically with PostgreSQL.
