More than 10 years ago, when I began my career as a database professional, the list of major client-server database companies included IBM, Oracle, Sybase, and Informix. (My working definition of major is "likely to be chosen for a new client-server project.") Over time, IBM and Oracle thrived as database vendors, Sybase became a nonplayer, and a new player—Microsoft—became a serious competitor.

Historically, Informix has had excellent leading-edge technology but it has squandered its advantages through inept management and marketing. IBM recently saved Informix from its misery when IBM announced plans to purchase Informix's database assets for $1 billion. So now we're down to three major database vendors.

Informix had and still has great technology. But I don't think IBM bought Informix for its technology. IBM bought Informix's customer base, about 100,000 companies. According to Steve Mills, senior vice president and group executive of IBM's software division, the acquisition essentially doubles the size of IBM's business in databases that run on UNIX and Windows.

What does the acquisition mean for Informix customers? "No customer will be forced to move to DB2," says Janet Perna, general manager of IBM's data-management division. Reality becomes clearer when you consider two key points. First, IBM says it plans to continue to sell and enhance Informix's database products, but the company will integrate key features and technologies from the existing Informix product line into DB2 Universal Database (UDB). Second, IBM says that the goal of development on Informix's next-generation database (code-named Arrowhead) won't be to create a new database product that integrates disparate Informix technologies into one product. Rather, IBM will roll new feature development into DB2 UDB. So if you're an Informix customer, you won't have to upgrade if you're content with today's Informix products. But don't expect anything new and exciting down the road unless you move to DB2.

What if you aren't an Informix customer or professional? It's important to keep abreast of the competitive landscape, and the acquisition could have repercussions for you.

IBM's investment in Informix's customer base is worthless unless IBM can convince Informix customers to stay in the family fold and upgrade to DB2. That goal will require a robust, sophisticated, yet easy-to-use "upgrade and migration strategy" for moving from Informix to DB2. What works for migrating Informix customers to DB2 can be applied to other migration paths, so I fully expect IBM to create compelling migration offerings to entice Oracle and Microsoft customers. Oracle and Microsoft will respond in kind, leading to a war of attrition among the database vendors as they fight heart and soul to capture your database dollars.

IBM says it's on the anti-Oracle warpath. The company stresses that the motivation behind the Informix acquisition is all-out competition. "We're bulking up; we're significantly increasing the size of our army," says Perna. "We're dead serious about winning this. We're playing for first place."

IBM discounts Microsoft as a serious competitor in the database market, citing SQL Server's Windows-only restriction. (Although the last time I checked, SQL Server held the world's fastest Transaction Processing Performance Council's TPC-C benchmark score.) Acknowledging Microsoft as a serious competitive threat gives SQL Server inherent credibility, something IBM tries to avoid. Nevertheless, you can expect trench warfare in the database market. Only three database vendors are left, and they all want your business.