What is it?
IBM's DB2 is a relational database management system (RDBMS), widely used in enterprises. In recent years, IBM has been working to widen the range of platforms its flagship relational database runs on, and also to deepen its capabilities. Recent additions to DB2 9.5 included substantial enhancements to DB2 Data Warehouse Edition (DB2 DWE). Combined with IBM's recent purchase of Cognos, the surge of activity in data warehousing signals a new focus on business intelligence.
With DB2 9.1, IBM introduced pureXML, turning DB2 into a hybrid relational/XML database. IBM has also been increasing support for other suppliers' implementations of SQL to meet the competition from both traditional suppliers such as Oracle and Microsoft, and open source databases such as MySQL.
IBM is progressively introducing automation, such as "autonomic" tuning, to assist with the administration of DB2, but the company has certainly not yet deskilled the job of the database administrator: DB2 DBA certification is widely regarded as among the most challenging that IBM offers.
Where did it originate?
DB2 was arguably the first commercially available database to build on Ted Codd's relational model, which was developed at IBM in the 1970s. Oracle, first shipped in 1979 with basic SQL functionality, is sometimes claimed to be the first commercial RDBMS. DB2 was first made available on MVS mainframes in 1983. In 1996, DB2 was transformed into the object-relational DB2 Universal Database, and support for Windows, Solaris and HP-UX was added, followed by Linux.
What's it for?
XML data can be queried using either SQL or XQuery, and applications can access and store XML and relational data. DB2 has application programming interfaces for old and new languages: RRexx, PL/I, Cobol, RPG, Fortran, C and C++, Java, Python, Perl, PHP and Ruby, with support for Microsoft's .net Common Language infrastructure.
DB2 9.5 increases support for Perl, PHP and the Ruby on Rails framework: for example, the DB2 Perl driver now supports pureXML. There is a new IBM Data Studio to replace the DB2 Developer Workbench, as well as integration with the IBM-backed Eclipse integrated development environment, and Microsoft's Visual Studio and other .net IDEs.
What makes it special?
Version 9.5 introduced the IBM Data Server Driver for ODBC, CLI, and .net to simplify mass application deployment on Windows.
How difficult is it to master?
Basic DB2 certification will take five days of training for those already familiar with SQL databases, and up to 20 days for beginners. There are various routes in for developers with C, Java and other languages.
DB2 9.5 brought in more autonomic functionality to simplify administration. There is a GUI for administrators that uses lots of wizards, but old hands use the far more flexible and scriptable command-line interface.
What systems does it run on?
As well as the Linux, Unix, Windows (LUW) version, DB2 is available for IBM's mainframe operating system z/OS, with some features exclusive to the mission-critical mainframe environment. DB2 LUW comes in a full-feature Enterprise Edition and reduced-feature editions for workgroups and developers (DB2 Express, which is available as a further reduced free download, DB2 Express-C, for Linux or Windows.
Rates of Pay
Database administrators earn £30,000 to £40,000. A premium is paid for DB2 data warehousing skills.
IBM's own range of classroom and online training can be found on its UK site. The big generalist training companies provide DB2 courses, as do many small specialists. For experienced database specialists, more in-depth information on installation, administration, troubleshooting and application development can be found on IBM's developer site, and also on IBM's developerworks.