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Java, .Net object DB rev’d

Jun 5, 2008 — by Eric Brown — from the LinuxDevices Archive — 1 views

McObject has upgraded its embedded, open source, object-oriented database management system (OODBMS) for Java and .NET environments. Perst 3.0 adds full-text search, embedded Java compression, improved documentation, and .NET native language querying (LINQ), says McObject.

With a core consisting of a mere 5,000 lines of code, Perst is said to pose very little impact on system resources. Because Perst stores data directly in Java objects, says McObject, there is no need for data-packing or unpacking code to map between the application's data model and the database's data model. Perst's specialized collection classes optimized for different data layouts and access patterns are said to ease the process of accessing objects.

In January, McObject announced that Perst was verified Android compliant by the Open Handset Alliance (OHA), the industry group overseeing the Google-backed, Linux-based phone stack. In the open source database realm, the dual-licensed Perst competes with the Java- and .NET-compatible DB4Objects' db4o, which was released under the GPL in 2004.

Perst 3.0's new full-text search feature uses a standard b-tree to store an inverse index of keywords, says McObject, and it adds only “a few kilobytes” to the small footprint software. By improving the software's integration with the open source Apache Lucene information retrieval library, users no longer need to install the “several hundred kilobyte” Lucene .jar file, says the company.

The.NET version of Perst adds support for LINQ, a Microsoft .NET Framework component that adds SQL-like querying capabilities to languages such as C# and Visual Basic. McObject's “micro-footprint” Perst Lite for Java ME has also been upgraded to version 3.0. Already some 30 percent smaller in size than Perst, with the new on-the-fly compression capability, Perst Lite can reduce stored data's size by an average of three to five times, says McObject.

Perst 3.0's documentation has been improved, as well. It now offers a concise, illustrated tutorial, says the company, and Perst 3.0 for .NET's API guide has been updated to the MSDN-like formatting familiar to .NET programmers.

McObject also sells a more traditional, Linux-compatible ExtremeDB embedded database that maintains a code footprint as small as 50KB, enabling it to run in memory for most embedded applications. The company sells a high availability version of ExtremeDB, and it recently announced a new kernel-mode version.


An open source evaluation version of Perst version 3.0 is available for free download with complete source code, here. McObject also offers a commercial license for Perst.

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