users@jpa-spec.java.net

[jpa-spec users] [jsr338-experts] outer fetch joins with on-conditions

From: Linda DeMichiel <linda.demichiel_at_oracle.com>
Date: Wed, 31 Oct 2012 12:51:29 -0700

I've been having an interesting discussion with a user on the JPA JIRA with
regard to outer fetch joins. See the issue http://java.net/jira/browse/JPA_SPEC-40

The issue is basically whether an outer fetch join with on-condition
can result in an entity whose state/relationships have been inconsistently
fetched.

Since we don't currently support the use of identification variables on
the right hand side, I believe that we currently do not have a problem.
Please double-check whether you agree with me on this or not.

However, the ability to specify identification variables here has also be requested,
and is something that we could plausibly add in future. See the issue
http://java.net/jira/browse/JPA_SPEC-28

I'd like input from the group with regard to these issue, and whether
we should consider:

1) not supporting outer fetch joins with on-conditions
2) not (i.e., never) supporting outer fetch joins with the use of identification
    variables on the right hand side
3) not supporting the use of on-conditions with outer fetch joins that use
    identification variables on the right hand side.
4) other??

-Linda