Difference between revisions of "EclipseLink/Features/Core"

Revision as of 21:00, 9 October 2007

EclipseLink Core Functionality

These core infrastructure features are leveraged by multiple persistence services.

Mapping

EclipseLink offers developers the ability to map a persistent POJO domain model. These persistent object types known as entities allow developers to design and implement a domain model without coupling to a particular persistence service. EclipseLink allows the domin model to be implemented without:

• inheriting from a common persistent superclass
• implementing a common persistence interface
• implement any persistence functionality within the entity classes

Class Descriptor

The ClassDescriptor represents the mapping of a single class to one or more data source artifacts. The core functionality of the ClassDescriptor provides default support for constructing and accessing the attributes of an entity throgh the use of reflection.

• Instantiation Policy
• Clone/Copy Policy

Transactions

• Transaction Modes
  • LOCAL
  • JTA
• UnitOfWork
  • Transaction isolated cache
  • Registration of objects
    • Register: New or existing objects
    • Register New Object
    • Register Existing Object
  • Merge
    • Deep Merge
    • Shallow Merge
    • Merge with relationships
  • Change Tracking
    • Deferred: Changes are detected at commit/flush by comparing working copy against backup copy made when object is registered into UnitOfWork
    • Object mark-dirty
    • Attribute Change Tracking

• • Nested UnitOfWork

Sessions

• Server Session
• Database Session
• Session Broker

Caching

• Shared Cache per Server/Database Session
• Isolated Cache per client
• Cache Type and initial/default size
  • SOFT-WEAK
  • HARD-WEAK
  • WEAK
  • FULL
  • NONE
• Query cache usage
  • Check cache by primary key
  • Check cache only
  • Check cache then database
  • Check cache only

UnitOfWork

• Change Tracking
  • Deferred
  • Object-Level Mark Dirty
  • Attribute Change Tracking