Why Use DB2?
Like Oracle, the DB2 RDBMS can handle huge data warehouses (aka databases). IBM's DB2 product has a long history in the mainframe world and a growing reputation in the Unix and Windows worlds. Many organizations standardize on DB2 across the enterprise because they're familiar with using it on one platform (mainframes, for example), and the learning curve is smaller to just learn the administration and development differences on a different computer/operating system platform than to learn a completely new database. Additionally, when an organization is using IBM computer hardware and (in some cases) an IBM operating system (such as AIX, IBM's version of Unix), using a database provided by IBM means that when technical support is needed on any aspect of that system, there is only one vendor to call-IBM.
As one of the top-tier databases, DB2 is constantly battling other enterprise databases on benchmark results. In fact, DB2 may be chosen in some organizations for its excellent performance in a particular situation. (As with Oracle, specific benchmarks won't be discussed in this article because database software performance is continually being adjusted by vendors.) Because of DB2's years of presence in the database arena, and its IBM support, many IT organizations consider it to be another "safe" option, especially for large databases. As a company with many decades of experience in mainframe data processing, IBM has shown that it knows how to create software that can handle significant workloads, and that its staff can provide a very high level of support to mission-critical IT environments.
Job Demand
Job demand for those proficient in using DB2 is very high. Searches of several popular employment sites, such as www.monsterboard.com, showed that many large companies and consulting firms are interested in those with DB2 expertise. Again, more than 1000 openings appeared in the search results at each site. The DB2 Universal Database (UDB) platform is gaining in popularity as it becomes available on more platforms. As a result, job demand for DB2 professionals is expected to continue to grow in the future.
Training Options and Resources
Because DB2 is an enterprise database, many DB2 professionals work in larger business environments that value certifications. As of this writing, IBM offers DB2 certifications on two different versions of the product and includes two tracks: administration and design.The exams are fairly DB2 specific, and both the administration and design exams require SQL proficiency in addition to knowledge of the DB2 UDB product itself.
Courses and Certifications
IBM Certified Solutions Expert in DB2 UDB Database Administration for Unix, Windows, and OS/2 and IBM Certified Solutions Expert in Database Development for Unix, Windows, and OS/2 are IBM's two basic certifications.The first is for those specializing in DB2 database administration, and the second is for those specializing in DB2 database design and development. There are separate versions of each certification for different versions of the DB2 product. Currently, DB2 version 6.1 is the latest release. Each of these tracks requires passing two exams-a "fundamentals" exam, and then a second exam specific to either administration or development. IBM also offers advanced level certifications on topics such as data replication and using DB2 in a clustered system environment. For more information on DB2 certification, you can check out the DB2 section of IBM's certification site at www.ibm.coni/education/certify/certs/db_index.phtnil.You can also find information on IBM's DB2 administration and development classes including IBM's new DB2 classes for Linux users at www-3.ibm.com/services/learning/.
Self-Study Options
You can start learning DB2 by downloading a trial version of the product from www.ibm.com/db2.Then, acquire an introductory DB2 book or two (some of these are mentioned in the "Books" section later in this article), install the product, and work with the product. To augment your studies, check out some of the Web sites listed in this article, particularly the list of DB2 links, for the latest information on DB2.
Additional Resources
The following sections provide you with some additional information about database administration and design, including related terminology, books, and newsgroups.
Jargon Buster
The following terms pick up where the previous "Jargon Buster" section left off. Again, these terms are spoken and understood by database professional regardless of the database in which they specialize.
- SELECT-The SQL statement used to perform database queries, retrieving a specified set of columns in a specified set of rows from one or more database tables. For example, "SELECT CustomerName FROM Customer WHERE CustomerID=< 14682':" would retrieve the name of the customer whose Customer ID is 14682.
- INSERT-The SQL statement used to add rows of data to a table in the database.
- UPDATE-The SQL statement used to update one or more columns in existing rows of a table.
- DELETE-The SQL statement used to delete rows of data from a table.
- Normalization-The process of organizing a database design in a way that results in tables and relationships that adhere to the relational model, which is a set of rules of how to structure data in relational databases. The different levels of relational model compliance are known as "Normal Forms," and normalization is performed by applying rules, such as "No repeating groups of data items are allowed in a single row of a table."
- Locking-The process of restricting access to certain pieces of a database, generally because a transaction (or perhaps a program that is not formally a transaction in database terms) is updating or accessing those parts of the database and doesn't want another process to change the data until it is finished. There are many different types of locking, and not all are implemented by every database.
