[JDO-674] Support a way of defining inheritance strategy that results in a table per class with the table containing columns for all fields in the class (inc superclasses)

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: JDO 3 (3.0)
• Fix Version/s: JDO 3.1-rc1
• Component/s: api, specification, tck
• Assignee: Craig L Russell
• Reporter: Andy Jefferson
• Created: 28/Jan/11 18:38
• Updated: 12/Jun/15 12:49
• Resolved: 19/Oct/12 16:19

Description

JPA provides an inheritance strategy "TABLE PER CLASS". In JPA this is defined in the root of an inheritance tree and implies that all classes in the inheritance tree have their own table that contains columns for all fields (inc fields in superclasses). There is currently no way to achieve this with JDO's strategy specification capability.

Propose we provide one of the following
1. Just have a strategy "complete-table" specified in the root of the inheritance hierarchy that implies the same as the JPA situation. This is the simplest to define.

2. Have a strategy "complete-table" that can be specified on any class with the result that this class has a table containing columns for all fields (inc superclasses). There are difficulties in defining what happens in the case of a subclass - can it take any of the standard inheritance strategy settings ?