Oracle updates free Berkeley DB
Oracle has released revised versions of the three editions of its embedded Berkeley DB database. For the first time, Berkeley DB 4.7 supports the real time QNX RTOS operating system and reportedly makes better use of cache. For replication in high-availability applications, it has a "cycling master", though no details were included either in the product announcements, or the release notes. Another change in 4.7 is support for Direct Persistence Layers (PDF file), which first appeared in the Berkeley DB Java edition version 3. These layers allow direct, permanent, storage of Java objects. Java annotations are used to add meta-information, such as the primary and secondary key, and for persistence in the class definition.
The XML variety of the database implements the XQuery update function proposed by W3C for the adding, deletion, and editing of nodes in XML documents; it also reportedly provides greater speed with a cost-oriented optimizer and includes XQilla for the handling of XQuery requests. Oracle, says that primarily, it has improved scalability and performance; support for Google's Android and Apache Maven has also been added.
Berkeley DB is available under a free license. It does not use a client/server architecture, but rather provides a application programming interface (API). Because it takes up much less space than a full-grown server, it can be used in environments with limited resources.