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From "Christophe Lombart" <christophe.lomb...@gmail.com>
Subject Re: OCM:To Path or Not to Path
Date Wed, 08 Oct 2008 12:57:20 GMT
Personally, I like the rule 7 made by David.
http://wiki.apache.org/jackrabbit/DavidsModel#head-79ca455cb5a0f371923912cc1418831f0e68f674

In all cases, OCM can manage UUID but please understand that many content
applications can live without that.

2008/10/8 Aleksei Lukin <lukin@stu.cn.ua>

> Wednesday 08 October 2008 10:16:07 Boni Gopalan (BioImagene) написав:
> > Let me take a challenge I am facing right now to give the context of why
> > identities other than UUID is important - may be this is something
> specific
> > to the OCM interpretation.
> >
> > I mapped Foo , with mix:referenceable and by specifying an UUID field on
> > the the bean. I saved an instance of Foo. After some time I archived that
> > Instance (A normal enterprise requirement).  After some more time user
> > requests a restore.  Now if I restore using the same OCM layer I am going
> > to get a different UUID.  It is not desirable at all.  I would like the
> > state of the object to be restored just as it was before: including the
> > jcr:uuid.
> >
>
> Lets decide what realluy we  backup and restore.
> If you backup you make copy of object therefore you make ANOTHER object
> that lives on it's own and original object lives on it's own.
> So it is 2 different objects in any meaning.
> If repository does a copy it changes UUID for copy. If you do backup
> somewhere outside repository you can not use UUID of a copy anymore as
> primary key, you must save old UUID
> somewhere in backup copy as reference to original object and create new one
> for a copy.  Thus your restore code must handle UUID specially. JCR
> import/export code has options
> for UUIDs that allows to use UUIDS from system XML view or ignore them at
> import.
>
> We can think of UUIDs as a C/C++ pointers in infinite abstract memory. Each
> object lives somewhere and we can say to universe-wide MMU :) to find it.
>
> > So the simple notion of UUID being unique alone is not sufficient.  What
> > about a notion of UUID : <scope = "usecurrentifprovided">?
> >
> > OCM fully acknowledges this and has provided the notion of "id" through
> > "id=true" attribute.  I feel, for the completeness of such a notion we
> need
> > the ability to attach an ID generator with the intelligence of not
> > generating a new ID if one is provided.
>
> Do not think that id purpose to be some unique key. OCM just creates node
> with such name.
> May be Christphe needs it for collection mapping or whatever else...
> >
> > Thanks
> > Boni
>
>
> --
> SY, Alex Lukin
> RIPE NIC HDL: LEXA1-RIPE
>
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