PostgreSQL is an object-relational
database management system (ORDBMS) based on
POSTGRES, Version 4.2,
developed at the University of California at Berkeley Computer Science
Department. POSTGRES pioneered many concepts that only became
available in some commercial database systems much later.
PostgreSQL is an open-source descendant
of this original Berkeley code. It supports a large part of the SQL
standard and offers many modern features:
- complex queries
- foreign keys
- triggers
- views
- transactional integrity
- multiversion concurrency control
Also, PostgreSQL can be extended by the
user in many ways, for example by adding new
- data types
- functions
- operators
- aggregate functions
- index methods
- procedural languages
And because of the liberal license,
PostgreSQL can be used, modified, and
distributed by everyone free of charge for any purpose, be it
private, commercial, or academic.
