PostgreSQL is an Object-Relational Database Management System (ORDBMS) that has been developed in various forms since 1977. It began as a project at the University of California at Berkeley project named Ingres. 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 from a team of Open Source developers and contributors, worldwide.
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/or 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 that 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 is free from distribution restrictions, that 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.
There are two primary companies that provide commercial PostgreSQL products. These companies have re-branded PostgreSQL to fit into their own product lines. They are Great Bridge, LLC, and Red Hat, Inc.
The Great Bridge version of PostgreSQL is at 7.1, and is currently the same version of PostgreSQL distributed from the community. Like most Open Source companies, Great Bridge specializes in consulting, training and support for their product. If you purchase Great Bridge PostgreSQL, you will receive 30 days of installation support in addition to the software. This product is available for both Linux and Solaris.
The Red Hat version of PostgreSQL is called Red Hat Database, and is a very new product to the database market. Red Hat Database is based on the currently distributed Open Source version, PostgreSQL 7.1. Red Hat Database currently supports Linux only, and preferably Red Hat Linux 7.1.
The Open Source version of PostgreSQL only includes the database management system and the associated programming interfaces. The Great Bridge and Red Hat versions of PostgreSQL each include a graphical installer and limited support for the installation.
If you want to use Great Bridge PostgreSQL, but feel that you will not need support, you can also download Great Bridge PostgreSQL from their website at http://www.greatbridge.com.
The main factor in deciding whether or not to use the Open Source version of PostgreSQL or one of the commercially available versions should be your business requirements. If you have a knowledgeable on-site technical support staff, the community version may do well for you. However, if you need installation, configuration, and management support, you may be better served by purchasing a commercial version of PostgreSQL.
If you prefer to do business with smaller consulting companies, we have compiled a modest list of professional companies providing support for PostgreSQL in the section called Commercial Support.
Marketing would suggest that the commercial versions of PostgreSQL are somehow objectively superior to the Open Source versions of PostgreSQL. In reality, this is not the case. When deciding what version of PostgreSQL you are going to run, you need only be aware of your own needs.
For example, are you going to need installation support? Is a graphical installation important to you? If they are, then you should probably purchase a commercial version of PostgreSQL. However, if you or one of your staff are comfortable with compiling and configuring source code, the Open Source version could be more applicable to you.
There are two additional questions you may want to ask. Do you wish printed documentation and are you willing to pay for PostgreSQL? Both of the commercial distributions come with printed documentation. However, if you are currently reading this book, we hope you may not need the additional documentation. The other question relates to cost. Great Bridge PostgreSQL, as of August 2001, is priced at 495.00 USD. The Red Hat Database is priced at 2,295.00 USD.
The most important thing to remember when deciding on which version of PostgreSQL to use is this, from a perspective of general usage and feature availability, there is no practical difference between the Open Source versions, and the Commercial versions.
Outside of Great Bridge and Red Hat, there are many companies that provide consulting services to the PostgreSQL community. The following is a small list of consultancies providing commercial support for PostgreSQL.
Command Prompt, Inc. is located on the web at: http://www.commandprompt.com/
Command Prompt is a Linux managed services and PostgreSQL support company. They provide Linux and PostgreSQL support, including custom programming featuring PostgreSQL, C++, PHP, Perl, and their own LXP application server for PostgreSQL.
Command Prompt, Inc, you might have noticed, also authored this book.
Cybertec Geschwinde & Schvnig OEG is located on the web at: http://postgres.cybertec.at/
Cybertec provides training courses, support, consulting, and cost effective high-end systems. Cybertec services the German speaking region (Austria, Germany, Switzerland).
dbExperts is located on the web at: http://www.dbexperts.com.br/
dbExperts offers training courses, specialized support for development and commercial products for PostgreSQL. dbExperts is located in Brazil and provides services in the Portuguese language.
PostgreSQL, Inc. is located on the web at: http://www.pgsql.com/
PostgreSQL, Inc. offers support for PostgreSQL, database hosting, and promotional materials.
Software Research Associates is located on the web at: http://osb.sra.co.jp/
Software Research Associates offers a range of services to aid customers with Open Source software based systems. Support from this company is also available in Japanese.
The PostgreSQL community provides active support to users of PostgreSQL via a number of mailing lists. There are several user mailing lists that you can subscribe to, segregated by topic (e.g., pgsql-general, pgsql-hackers, etc). The mailing lists for PostgreSQL users are quite thorough, and cover everything from general discussion, to support on developing with one of the many PostgreSQL programming interfaces. For a complete list of mailing lists with associated descriptions please visit the PostgreSQL website at: http://www.postgresql.org/