Re: [eclipselink-users] most optimal wy to persisted list?

[Phillip Ross <phillip.ross@xxxxxxxxx>]

Thanks James.  I've been reading through all of the EclipseLink relational and JPA docs and trying to figure out the best way to do this.

Since the 1.0.2 build is the one downloadable from the eclipselink website I'm assuming 1.1 and 2.0 builds are not ready for primetime.  Or maybe the site wasnt updated and there actually is a 1.1 release I'm missing?  I have seem the eclipse wiki not being completely up-to-date in the past, but I usually see some announcement after a release somewhere.

Anyway, I think I'll have to go with the third method and define another intermediate class with an index field.  Luckily the requirements for this specific case do not require the exact semantics of an array list or anything that holds their exact index.  Just an ordered list I think will meet the requirements.

Thanks again
- Phillip



----- Original Message ----
> From: James Sutherland <jamesssss@xxxxxxxxx>
> To: eclipselink-users@xxxxxxxxxxx
> Sent: Monday, March 2, 2009 9:57:19 AM
> Subject: Re: [eclipselink-users] most optimal wy to persisted list?
> 
> 
> JPA 2.0 and EclipseLink 2.0 will support ordered lists using an index column
> in the database.  BasicCollections will also be standardized as
> ElementCollection mappings in JPA 2.0.  The EclipseLink 2.0 builds already
> have this functionality, and some of the functionality was in the 1.1
> release.
> 
> The drawback with serializing is that you cannot query on the list values. 
> However, if you don't need to query the values, then there is probably
> nothing wrong with serializing the list.
> 
> You can also map the list as a OneToMany in JPA 1.0, and define a class for
> the value that also contains an index field to order the list by.
> 
> 
> Phillip Ross-3 wrote:
> > 
> > 
> > Hi all...
> > 
> > I'm just wondering, for EclipseLink, what is the most optimal way to
> > persist List fields of an entity.  The @BasicCollection does not include
> > persisting the index of the List elements (as far as I can tell) so when
> > the EntityManager is cleared or a new one which does not alreayd know
> > about the in-memory version of the List is used... the index values are
> > lost.  In the current implementation, there are lists being serialized to
> > byte arrays and stored as LOB columns which is not... optimal :)
> > 
> > Any advice on this?  Portability to other JPA providers is of little
> > concern, if any.
> > 
> > Thanks!
> > - Phillip
> > 
> > _______________________________________________
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> > eclipselink-users@xxxxxxxxxxx
> > https://dev.eclipse.org/mailman/listinfo/eclipselink-users
> > 
> > 
> 
> 
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