This page in other versions: Unsupported versions: 6.3
PostgreSQL
Prev Chapter 1. Introduction Next

What is Postgres?

Traditional relational database management systems (DBMSs) support a data model consisting of a collection of named relations, containing attributes of a specific type. In current commercial systems, possible types include floating point numbers, integers, character strings, money, and dates. It is commonly recognized that this model is inadequate for future data processing applications. The relational model successfully replaced previous models in part because of its "Spartan simplicity". However, as mentioned, this simplicity often makes the implementation of certain applications very difficult. Postgres offers substantial additional power by incorporating the following four additional basic concepts in such a way that users can easily extend the system:

classes
inheritance
types
functions

Other features provide additional power and flexibility:

constraints
triggers
rules
transaction integrity

These features put Postgres into the category of databases referred to as object-relational. Note that this is distinct from those referred to as object-oriented, which in general are not as well suited to supporting the traditional relational database languages. So, although Postgres has some object-oriented features, it is firmly in the relational database world. In fact, some commercial databases have recently incorporated features pioneered by Postgres.


Prev Home Next
Introduction Up A Short History of Postgres
Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group