Users of the open-source MySQL database appeared unworried after the announcement Tuesday of Oracle's purchase of Sleepycat Software.

BerkeleyDB, the popular embedded open-source database for which Emeryville, Calif.-based Sleepycat provides commercial support, is one of the many choices MySQL users have as the storage engine for their data.

After Oracle's purchase last fall of InnoBase OY, the Finnish maker of InnoDB, another MySQL storage engine, many users fretted that Oracle bought the company simply as a hostile move against MySQL, said John Abbott, an analyst at New York-based consulting firm The 451 Group. The market for large relational databases, for which Oracle and IBM share leadership, has been eroded in recent years as companies gravitate toward lighter-weight, easier-to-use databases such as MySQL.

"It was hard to see why Oracle did it other than to screw up MySQL," Abbott said.

BerkeleyDB is also popular, with Sleepycat claiming that it has been deployed more than 200 million times. It is embedded in several well-known open-source products, including the Linux and BSD Unix operating systems, Apache Web server, OpenLDAP directory and OpenOffice productivity suite.

Despite its popularity elsewhere, BerkeleyDB isn't widely used by MySQL users, said Jeremy Cole, a former MySQL employee who now helps oversee about 8,000 MySQL databases used worldwide by Yahoo Inc.

"Basically, the BDB storage engine was added to MySQL in the early days as a prototype for adding transactional support to MySQL," Cole said. "Once BDB was working with MySQL, InnoDB came along shortly afterwards and quickly surpassed BDB in usefulness, speed and features. No one has looked back since."

Boyd Hemphill, an Austin-based MySQL administrator for the state of Texas, concurred.

BerkeleyDB "was never fully supported, and I am unaware of anyone using it in production," Hemphill said. "Oracle's purchase of InnoDB was much more shocking [and] troubling because it was a much better supported engine."

Christof Wittig, CEO of db4objects, a San Mateo, California-based open-source embedded database maker, said that Oracle might "quietly dead-end BerkeleyDB," a possibility that he said has already garnered inquiries to his company from Sleepycat customers.

But Noel Yuhanna, an analyst at Forrester Research, said Oracle is trying to embrace embedded and open-source databases -- markets it formerly avoided as distracting or cannibalizing its core Oracle database sales.

"Oracle is very unlikely to change its licensing terms and prices, because it defeats the purpose of these acquisitions, which is to offer more options and tap into the open-source market," Yuhanna said. "Both of the technologies have been successful because of their low cost and reliability in the product. What we find is that the No. 1 concern that the majority of Oracle customers have today is pricing/licensing, so if they increase the Sleepycat-InnoDB prices, they would be shooting themselves in the foot."

The real impact of the Sleepycat deal is that it could start a wave of consolidation that could "open the door for a possible acquisition of MySQL," Yuhanna said. "As open-source databases start to penetrate even further in the closed-source database market, there will be two options available to DBMS vendors. One would be to go head-on against open-source databases; the other, to join hands. The latter would be the more logical path, given that open-source databases have become unstoppable."