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From Pinaki Poddar <ppod...@apache.org>
Subject Re: Replication Question
Date Mon, 16 Mar 2009 20:33:49 GMT

Hi,
> A will have its list field contain many instances of class X. When I
> persist it, the first DB contains the 
> complete number of X instances and the A instance that's holding the list.
> The second DB on the other 
> hand, only contains the A entity without the X entities.

This is a consequence of "collocation constraint" imposed by Slice. When A
is persisted in slice1, all the related X instances are persisted in slice1
as well automatically by Slice. If A is the 'root' instance (i.e. the
explict argument to persist() call) then Slice checks if A is a replicated.
But it does not check if anything reachable from A i.e. the list of X is
replicated or not. 

This automatic decision can be relaxed and a JIRA issue OPENJPA-981 [1] has
been created. I hope to fix it shortly. Is it possible for you to work with
our nightly builds or you also need this change in earlier branches?

[1] https://issues.apache.org/jira/browse/OPENJPA-981



Teodoro Cue wrote:
> 
> Hi,
> 
> I'm using org.apache.openjpa.slice.ReplicationPolicy.Default to replicate
> all my entities into a backup DB.
> Here is my class structure with flat inheritance strategy:
> Interface C
> 
> @Entity
> @Replicated
> Abstract Class AC implements C
> 
> @Entity
> @Replicated
> Class A extends AC
>     @OneToMany
>     List<C> list;
> 
> @Entity
> @Replicated
> Class X extends AC
> 
> During runtime, an instance of class A will have its list field contain
> many
> instances of class X. When I persist it, the first DB contains the
> complete
> number of X instances and the A instance that's holding the list. The
> second
> DB on the other hand, only contains the A entity without the X entities.
> 
> Am I doing something wrong?
> By the way, the DB that I'm using is Embedded Derby for testing purposes.
> 
> 
> -Teody
> 
> 

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