What is it?
DB2 is IBM's relational database, first used for MVS mainframe environments. Since 1997, when database suppliers were investing heavily - and prematurely - in object-relational capabilities, it has been known as DB2 Universal Database (UDB). Two years ago, IBM took over former relational database management system competitor Informix and acquired 2,000 database experts and 120,000 customers.
DB2 holds the top of the RDBMS market with Oracle (depending on whether you read analyst reports from Gartner or IDC, and how you cut the market), but it is undoubtedly the leader on Linux.
Where did it originate?
DB2 was a result of the work done by Codd and Date at IBM's San Jose Labs. In 1981, IBM released its first SQL database, SQL/DS. This was followed in 1983 by DB/2, which was essentially SQL/DS rewritten for MVS. However, Oracle pipped IBM to market with the first RDBMS, released in 1979.
What is it for?
In a 2003 review, Bloor Research said its capabilities made it suitable for very large datawarehouse and online transaction processing/e-commerce transactions, although it is also available in Mid-range and Personal (and Personal Developer's) Editions.
What makes it special?
Stability and reliability, derived from its origin on the mainframe. Although the codebase for Windows, Unix and Linux is different to the version for z/OS and OS/400, DB2 is still a datacentre-strength product, not a desktop filing system like some of its competitors. Both versions have the same look and feel.
Bloor Research said its parallel capabilities were as good or better than any competitor. IBM has surrounded DB2 with middleware products, offering gateways to most other databases and making it possible to build consolidated and "federated" databases on and around DB2.
This contrasts with Oracle's centralised approach - which has its own advantages. DB2 has its own business intelligence capabilities - DB2 Olap Server and Dataminer - but is also optimised for other online analytical processing tools.
How difficult is it to master?
IBM is working towards self-configuring, self-healing and self-optimising systems. In the meantime, life for developers and database administrators is easier than it used to be, thanks to a new generation of graphical tools and wizards which came out with version 8.1 in 2003.
Where is it used?
IBM rules the large enterprise space, but it has been less successful at displacing Microsoft from the lower end.
What systems does it run on?
z/OS, OS/400, Windows, AIX, Linux, Solaris, HP-UX, and some mobile operating systems (for DB2 Everyplace).
Not many people know that...
US commentator Howard Fosdick, who analysed DB2 skill requirements in a white paper, said DB2 certification costs about half as much as SQL Server or Oracle, and involves fewer supplier revenue-generating exams.
What is coming up?
Version 8.1 is available for Linux, Unix and Windows; z/OS and OS/400 are following.
DB2 classroom training, online courses and CD-Roms are available from IBM, as well as free material on IBM's Developerworks site. Most big independent training companies and many small specialists offer DB2 courses. There is also a DB2 magazine and user group.
Rates of pay
Salaries for database administrators start at £30,000, rising to £45,000 to £50,000 in the City. Analyst programmers can expect £25,000 to £35,000. There is still plenty of work for the Cobol/Cics/DB2 combination. Newer skills being asked for include Cics, Linux, Java and XML.