McObject Perst 4.0 Embedded Database

McObject Perst 4.0 is the latest version of their open source, object-oriented embedded database for Java and .NET. Perst 4.0 expands Perst’s usefulness in a broad range of applications by enabling it to add persistence to any object — including objects created by other programs, those for which source code is unavailable, and even objects created in different programming languages. Perst 4.0 also adds rich new tools for developing mobile and embedded applications in both Java ME and in Google’s Android environment. For Perst Lite (the Java ME edition of Perst), version 4.0 adds seamless integration with the popular EclipseME integrated development environment, as well as improved handling of memory and storage.

In the new version of Perst, “foreign” objects or objects derived from any class can be stored in the database, increasing Perst’s usability with external programs. As a result, Perst can be added as storage for existing applications such as commercial or open source class frameworks, including GUI classes, object-request brokers, and industry-specific solutions; UML modeling tools that generate classes from wizards; and programs whose source code is not available.

Perst 4.0′s enhancements for mobile and embedded application developers include a new example application (called PIMindex for Java ME, and ContactsIndex for Android) that builds on the embedded database’s full-text search to provide a local search engine for contact management files on a cell phone or other device. The example software, which is provided with full source code, could be extended to provide search capabilities for PDF, word processing, HTML and other stored files. Both PIMindex and ContactsIndex are included in the Perst 4.0 for Java distribution (which also includes both Perst and Perst Lite).

Perst Lite 4.0 Features

  • EclipseME Support
    Perst Lite 4.0 now works with EclipseME, the Java ME plug-in to IBM’s free Eclipse development framework.
  • Full-text Search
    Perst Lite stores an inverse index of keywords, with parsing and stemming of indexed text performed either by user-defined code or by Perst’s default simple parser and stemmer. This feature supports logical operators and calculates search results’ relevance to a query.
  • Automatic Determination of Storage Type
    Perst Lite now chooses the correct storage layer implementation from among Java ME Connected Device Configuration (CDC) file interfaces: JSR-75, which allows access to file systems on certain devices; or Java ME’s Record Management System (RMS) persistent storage mechanism.
  • Support for Weak References
    This simplifies the object caching process by allowing objects to be claimed by Java ME’s garbage collection, thus eliminating the need for developers to explicitly control cache size.

More info: Perst Open Source Java Database / .NET