No one so far has ripped out a clustered Oracle 9i database on multiprocessor Sun servers and replaced it with a free, open source database downloaded from the Web, running on a bunch of Intel-based Linux servers.

But a growing number of network executives are pioneering these freely available data managers. They're finding that open source databases are reaching a state where they can become the latest addition to their inventory of open source tools, including the Linux operating system, the Apache Web server and the Tomcat Java servlet engine.

Users say the attractions include:

• Very fast performance, especially in read-only applications.
• No or nominal, licensing costs.
• Low administrative and operational costs.

Burlington Coat Factory Warehouse is a Linux user looking at the open source database technology. The Burlington, N.J., company deployed Linux servers in its retail stores nationwide a few years ago.

"We're not sure about embracing open source databases yet," says Brad Friedman, the company's vice president of information servers. "But we will probably do so in our retail locations. As to the back-end servers, we're still ingrained with Oracle, which has a fair amount of support for Linux."

Friedman's comment shows a typical pattern in companies that are weighing, or experimenting with open source databases. High-volume database updates, which are the essence of transaction-processing applications, remain anchored on products such as Oracle's 9i and IBM's DB2 Universal Database, and increasingly Microsoft's SQL Server. But there are a host of new application areas that don't require the complex, and expensive, features found in these massive products.

"Some of our groups that use Oracle never were wedded to Oracle's high-priced features," says Jeremy Zawodny, technical Yahoo, for Yahoo, Inc., in Sunnyvale, Calif. "If you don't need these features, you probably don't have to pay the price for them [with an open source alternative]."

At Yahoo, the MySQL open source database, from MySQL AB of Sweden, has "spread from being used by a few groups to the core infrastructure" of the Internet portal, Zawodny says. MySQL handles vast amounts of data from hundreds of daily news feeds, such as Associated Press and Reuters, stock market tickers and so on. The data is stored, marked up and posted in Web pages in response to mouse clicks by Yahoo visitors.