A Short History of Postgres

The Object-Relational Database Management System now known as PostgreSQL (and briefly called Postgres95) is derived from the Postgres package written at Berkeley. With over a decade of development behind it, PostgreSQL is the most advanced open-source database available anywhere, offering multi-version concurrency control, supporting almost all SQL constructs (including subselects, transactions, and user-defined types and functions), and having a wide range of language bindings available (including C, C++, Java, perl, tcl, and python).

The Berkeley Postgres Project

Implementation of the Postgres DBMS began in 1986. The initial concepts for the system were presented in The Design of Postgres and the definition of the initial data model appeared in The Postgres Data Model. The design of the rule system at that time was described in The Design of the Postgres Rules System. The rationale and architecture of the storage manager were detailed in The Postgres Storage System.

Postgres has undergone several major releases since then. The first "demoware" system became operational in 1987 and was shown at the 1988 ACM-SIGMOD Conference. We released Version 1, described in The Implementation of Postgres, to a few external users in June 1989. In response to a critique of the first rule system (A Commentary on the Postgres Rules System), the rule system was redesigned (On Rules, Procedures, Caching and Views in Database Systems) and Version 2 was released in June 1990 with the new rule system. Version 3 appeared in 1991 and added support for multiple storage managers, an improved query executor, and a rewritten rewrite rule system. For the most part, releases until Postgres95 (see below) focused on portability and reliability.

Postgres has been used to implement many different research and production applications. These include: a financial data analysis system, a jet engine performance monitoring package, an asteroid tracking database, a medical information database, and several geographic information systems. Postgres has also been used as an educational tool at several universities. Finally, Illustra Information Technologies (since merged into Informix) picked up the code and commercialized it. Postgres became the primary data manager for the Sequoia 2000 scientific computing project in late 1992.

The size of the external user community nearly doubled during 1993. It became increasingly obvious that maintenance of the prototype code and support was taking up large amounts of time that should have been devoted to database research. In an effort to reduce this support burden, the project officially ended with Version 4.2.


In 1994, Andrew Yu and Jolly Chen added a SQL language interpreter to Postgres. Postgres95 was subsequently released to the Web to find its own way in the world as an open-source descendant of the original Postgres Berkeley code.

Postgres95 code was completely ANSI C and trimmed in size by 25%. Many internal changes improved performance and maintainability. Postgres95 v1.0.x ran about 30-50% faster on the Wisconsin Benchmark compared to Postgres v4.2. Apart from bug fixes, these were the major enhancements:


By 1996, it became clear that the name "Postgres95" would not stand the test of time. We chose a new name, PostgreSQL, to reflect the relationship between the original Postgres and the more recent versions with SQL capability. At the same time, we set the version numbering to start at 6.0, putting the numbers back into the sequence originally begun by the Postgres Project.

The emphasis during development of Postgres95 was on identifying and understanding existing problems in the backend code. With PostgreSQL, the emphasis has shifted to augmenting features and capabilities, although work continues in all areas.

Major enhancements in PostgreSQL include: