The new features are designed to improve performance, availability and ease-of-use for developers of the open-source database.

One of the major goodies in the update is the ability of developers to upgrade the database without bringing it down.

The nonstop upgrades feature is aimed at customers that have to have 99.999 percent system uptime.

As far as the multi-version concurrency control goes, the new functionality gives each user a database snapshot.

Designed to improve performance of highly concurrent systems with mixed read/write, it allows administrators to manage changes coming in from many users simultaneously.

Another biggie in the update is a replication framework: a place in which users can access pre-built functions to build replicated or highly available systems.

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Oracle purchased the purveyor of Berkeley DB—Sleepycat Software— in February 2006.

At the time, Robert Shimp, vice president of technology marketing at Oracle, said that the Redwood Shores, Calif., database king purchased Sleepycat due to its popularity on edge-based devices like network switches, on all kinds of embedded storage systems, and on application security systems.

Oracle has been in the embedded database market for some time, with its Oracle Lite database for mobile devices and its TimesTen, designed for high-performance, in-memory database applications.

With those two products at the low end and the high end, respectively, Berkeley DB would serve to fill an important gap in the middle, Shimp said at the time of the purchase.

Berkeley DB's having open-source code is vital for customers in the mid-market, Shimp said, given their need to customize database code in embedded devices—each of which has its particular constraints.

Of course, further penetrating the open-source community—and making money off it—was an equally compelling cause for Oracle to snap up the database.

With the release of R4.5, Oracle's showing its commitment to that open-source developer community, as well as to its commercial customers, said former Sleepycat Vice President of Marketing Rex Wang—now VP of embedded systems marketing at Oracle—in a statement.

"The latest release of Oracle Berkeley DB reflects Oracle's commitment to providing both open-source and commercial developers with choice and flexibility, through the continued innovation and development of this open source, embeddable database," Wang said in the statement.

"This version adds compelling new features, reduces complexity and helps developers build and deploy applications requiring fast, reliable storage without human administration."

Oracle's statement also quoted stats from a June 2006 report on the open-source database market by Forrester researcher Noel Yuhanna.

According to Yuhanna, that market now measures about $400 million, including support, services and licenses.

Forrester predicts it will more than double, hitting $1 billion, by the end of 2008.

Oracle Berkeley DB Release 4.5 is generally available under the same dual license that Sleepycat had before the Oracle purchase.

To wit: A no-cost open-source license permits redistribution if the application using Oracle Berkeley DB is open source.

A commercial license is available for redistribution of proprietary applications. Oracle Berkeley DB is available for download here.

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