PostgreSQL is a relational database manager system based on postgres version 4,2, developed in the department of Computer Sciences in the University of California at Berkeley. Postgres was a pioneer in many concepts that appeared much later in some of the commercial database systems.
PostgreSQL is a open source descendant of the original code of Berkeley. It supports SQL92 and SQL99 in addition to other modern characteristics, among them:
Also, PostgreSQL can be extended by the user in several forms, for example adding:
- Complex queries
- Foreign keys.
- Transactional integrity.
- Concurrency control multi-version.
And because of its license, PostgreSQL can be used, modified and distributed by anyone free of position for any intention, private, commercial or academic.
- Data types
- Aggregation functions.
- Procedure languages.