[CAY-1025] Do something about to-many prefetch limitations

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2 branch, 2.0 branch, 3.0
• Fix Version/s: 3.0 beta 1, 3.0
• Component/s: Core Library
• Assignee: Andrus Adamchik
• Reporter: Andrus Adamchik
• Created: 08/Apr/08 18:10
• Updated: 08/May/10 10:31
• Resolved: 07/Sep/09 23:32

Description

http://cayenne.apache.org/doc/prefetching.html

"PREFETCH LIMITATION: To-many relationships should not be prefetched if a query qualifier can potentially reduce a number of related objects, resulting in incorrect relationship list."

This can bite an unsuspecting user... So we either

1. Address the core limitation by building a correct prefetch query (use subselect?)
2. Detect these cases and throw an exception
3. Detect these cases and silently drop a prefetch

I should note that debugging these problems is very hard, as they look totally random until you get to the cause.