EclipseLink/DesignDocs/214661

Functional Specification: VM managed Entity detachment

ER 214661

Project overview

Allowing a Persistence Context to reference managed objects in a weak manner would provide Rich Clients an automatic memory management mechanism.

Currently JPA clients must manage memory foot print manually by controlling the lifetime of the PersistenceContext as well as the contents of the Persistence Context.

Within a Rich Client environment it is much easier for application developers to simply use the managed objects as the UI backing objects and leverage transparent persistence instead of creating a DOA layer.

Currently the only limitation with this approach is memory management. Persistence Contexts tend to grow and detaching objects is problematic. With this feature memory management can be delegated to the VMs garbage collection functionality through the use of weak references. End users must be aware of certain side effects of unpredictable detachment from the Persistence Context but as long as developers are aware of the limitations the feature should provide the needed functionality.

Goals:

Open Issues

This section lists the open issues that are still pending that must be decided prior to fully implementing this project's requirements.

Date	Author	Version Description & Notes

Decisions

This section lists decisions made. These are intended to document the resolution of open issues or constraints added to the project that are important.

Issue #	Owner	Description / Notes

Future Considerations

Issue #	Description / Notes	Decision