[hibernate-dev] Mutable natural key caching?

[Elias Ross]

On Wed, Sep 17, 2008 at 9:12 PM, Steve Ebersole <steve at hibernate.org> wrote:
> http://opensource.atlassian.com/projects/hibernate/browse/HHH-2879 ???
>

If you use Hibernate EntityManager, get the Hibernate Session and use
Criteria to query by natural ID and the entity was deleted, you end up
with an EntityNotFoundException. I reported the issue as: HHH-3478

I have a patch which fixes this problem, but it's a hack. From the issue:

In StandardQueryCache, there is a "catch" which handles
"UnresolvableObjectException" but not "EntityNotFoundException"

catch ( UnresolvableObjectException uoe ) {
  if ( isNaturalKeyLookup ) {
  //TODO: not really completely correct, since
  // the uoe could occur while resolving
  log.debug( "could not reassemble cached result set" );
  cacheRegion.evict( key );
  return null;
}

I'm thinking that by keeping an association mapped in the query cache
-- but I'm thinking that's not the right spot --
EntityManager/Session.remove() could trigger a removal of any natural
ID criteria query as well. And so could any update, if the natural IDs
were mutable. Anyway, you'd get rid of this hack, possibly.