OODBMS.ORG announced the addition of a "Persistent Patterns" section to its collection of resources for educators and practitioners. Three collections (as .pdf documents) of patterns comprise the initial set of resources. Also announced was a "Best Pattern Award" with any pattern added to the site prior to May 29,2009 being eligible for the Award. Voting will take place from May 29 until June 20, 2009.
ODBMS.ORG was Launched in 2005 to provide up-to-date, and free, information and materials on object database technology. The target audience for the site includes faculty and students and OO software developers in the open source community or at commercial companies. Although object databases have been available for decades, and are a recognized solution to the infamous "impedance mismatch" problem that arises between object programming and relational database persistence; until recently most developers have not had the opportunity to use them and therefore are likely unaware of best practices in this area. Persistence patterns will be a valuable resource for this community.
Three contributors have provide an initial set of patterns:
- Adrian Marriott, Principal Consultant, Progress Software Inc., contributes 14 patterns (one of which is an anti-pattern, including: "Persistent Singleton," "Bespoke Indexes," "Transaction Memo," and "Persistent Queue."
- Eugenia Stathopoulou and Panos Vassiliadis offer Design Patterns for Relational Databases in the context of a full discussion of the theoretical problem of persistence and the mapping of conceptual data models to physical, relational, models.
- Takenori Sato's introduces the idea of a Probabilistic Graph Model and uses an extension of the Composite Pattern to provide patterns applicable to search and RESTful design.
The Marriot paper is the most straightforward of the three, and the one with a format that will be most familiar to the Patterns Community. The other two papers are more oriented to academics and include valuable context and background information on persistence along with their patterns.
An Award for Best Persistent Pattern was announced and details of the call and the Award are available here.