Re: [DISCUSS] Named PMF proposal (JDOHelper enhancements)

[Craig L Russell]

On Feb 28, 2007, at 8:38 AM, Matthew Adams wrote:

Inline...

Call it what you want -- I only proposed these names.  I

wouldn't call

it persistence.xml, as the contents are not the same as the

are of course interpretable by the JDO implementation

JPA-specified content. If the persistence.xml is found, its contents

according to our

JPA alignment verbage defined in JDO 2.1.

ok. So a JDO2.1 impl has to understand both "persistence.xml"
(JPA format) and
this "jdo.xml" ? No problem if that is the case but just want
to understand
what we're specifying here since not everyone was on this conf call.

Yes, this is correct. I guess since JPA, which uses the base namespace "javax.persistence" and calls the file "persistence.xml", then we should

probably call JDO bootstrap file "jdo.xml".  Done.

I like it.

We could use the
same boot idea as JPA and have a

META-INF/services/javax.jdo.XXX file

defining the PMF(s) available, and it takes the one that
claims it supports
the required "persistence-unit" (or PMF)

I like this suggestion!  I assume the following would be

true -- please

correct where I've got it wrong.

* The name of this file is
"META-INF/services/javax.jdo.PersistenceManagerFactory"
        * This is a text file
        * The contents of the file would be the name of the provider's
implementation class of javax.jdo.PersistenceManagerFactory

Yes. See a mail by Erik to the lists on 19/01/2007 called
"Proposal for
Service Discovery". JDOHelper would then have the job of
finding all services
files of this name ("javax.jdo.PersistenceManagerFactory"),
and from the
contents finding the relevant PMF to instantiate for a
particular PMF name.

Ok.

Since this appears to be an extension to JDO and not the
simple mapping across
of terminology JDO-JPA (being able to read a
"persistence.xml"), I'd ask are
we just confusing users by having "persistenceUnitName" and
"transactionType"
for when a JDO impl reads a "persistence.xml", yet here we
also have a PMF
name (which is the same as a persistence-unit name) for when
we use this
file.

This was brought up on the conference call. A "persistence unit" is the

same thing as a "named PMF".

Yes.

We decided that we won't use the term
"named PMF" in the specification -- we'll just go with "persistence
unit".  There will be a JPA flavor (already specified) and a


As far as transaction type, I think they're the same.

corresponding JDO flavor (adding a name to a PMF, the getName() method).

Craig

There is nothing in JDO 2.0 that corresponds to JPA TransactionType. We're adding it to JDO 2.1. So there is no ambiguity and no reason I can think of to create a different name.

Craig, can you
please comment on transaction type?

-matthew

Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!

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