What is it?
PostgreSQL is an open source object-relational database management package. It is one of the pillars of Sun Microsystems' alternative to the Lamp (Linux, Apache, MySQL, Perl/Python/PHP) stack, with Solaris standing in for the Linux platform and PostgreSQL in place of MySQL.
In the two years since Sun began shipping the open source database, it has progressively integrated it with key features of its operating system, such as Predictive Self-Healing, Service Management Facility (SMF) and dynamic tracing.
Sun also offers support subscriptions for organisations too conservative to trust the help on offer from the open source software community.
With origins in the same team that produced the Ingres database package, PostgreSQL is a serious enterprise-class database. It supports storage of binary large objects, including images, sound and video.
PostgreSQL is shipped with both Solaris 10 and with the freely downloadable Solaris Express Developer Edition.
Where did it originate?
Sun Microsystems announced support for PostgreSQL in 2005, and shipped PostgreSQL 8.1.3 integrated with Solaris 10 6/06 the following June, having already released it with OpenSolaris.
Michael Stonebraker, creator of Ingres, began work on PostgreSQL in 1986 at Berkeley in California.
What is it for?
PostgreSQL has many of the features of commercial enterprise systems, including multi-version concurrency control, point-in-time recovery, asynchronous replication, hot back-ups and fault tolerance.
It offers single and multiple table inheritance, which uses object technology to enable tables to be derived from other tables.
Its query language, echoing Oracle's, is PL/pgSQL, and it runs stored procedures in other languages - including Java, Perl, Python, Ruby, TCL and C/C++ - for which it also has native programming interfaces. Its standard function library includes Oracle compatibility.
What makes it special?
Because of the nature of PostgreSQL's original user community, it is designed to have lower maintenance and tuning requirements than proprietary database systems. Under the terms of its open source licence, it can be downloaded and deployed as widely as required without incurring any cost.
Otherwise, the claim made for PostgreSQL is modest: "faster than other databases for some things, slower for others".
The integration with Solaris provides additional robustness. SMF, for example, enables application services to be restarted automatically if they are accidentally terminated or interrupted because of programming errors or hardware problems.
How difficult is it to master?
There are opportunities for developers in the many supported languages, although you will require some understanding of SQL. Experienced SQL database administrators can retrain for PostgreSQL competence in as little as two days.
Where is it used?
Sun is just one of many IT suppliers that use PostgreSQL. Others include Fujitsu, Red Hat, Apple and Cisco. Included among the declared users - a fraction of those who download and run it undeclared - are telecom providers Telstra and Skype, UN agencies, US government departments, and many universities.
What systems does it run on?
Solaris, including releases earlier than 10, although more work is involved for this, Linux, all flavours of Unix, Mac OS X and Windows.
What is coming up?
There are major releases of Postgres annually. Integration with Solaris follows after a few months, with OpenSolaris getting the new features first.
Build your own free PostrgreSQL training from resources on the websites listed below, or buy it from Sun Microsystems, Red Hat and many smaller (and cheaper) independent suppliers.
Sun occasionally holds showcases of free technology, such as PostgreSQL, but none are due in the UK.