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From "Patrick Linskey" <plins...@bea.com>
Subject RE: Using query hints for mapping extensions in orm.xml
Date Thu, 25 Jan 2007 18:07:35 GMT
... and option 4 is:

- user creates an orm.xml using the Sun XSD. This contains only
JPA-standard options, and is thus portable.

- user also creates an openjpa-orm.xml file using the OpenJPA XSD as
discussed already (or potentially a new OpenJPA-only XSD). This contains
only OpenJPA extension options. Again, the application is therefore
portable -- other vendors will clearly ignore the openjpa-orm.xsd file.

-Patrick

-- 
Patrick Linskey
BEA Systems, Inc. 

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> -----Original Message-----
> From: Albert Lee [mailto:allee8285@gmail.com] 
> Sent: Thursday, January 25, 2007 9:26 AM
> To: open-jpa-dev@incubator.apache.org
> Subject: Re: Using query hints for mapping extensions in orm.xml
> 
> Let's put this into a more concrete terms:
> 
> Given:
> 1) Existing JPA orm schema in
>           http://java.sun.com/xml/ns/persistence/orm_1_0.xsd
> 
> 2) OpenJPA supports its version of the orm schema in
> 
> http://incubator.apache.org/openjpa/xml/ns/persistence/openjpa
> _orm_1_0.xsd
>        Note: we need to find a more permanent home for this 
> schema other
> than putting it in incubator.apache.org. Suggestions?
> 
> 3) xml name space for both schema are:
>                      
> xmlns="http://java.sun.com/xml/ns/persistence/orm"
>          xmlns:openjpa="http://java.sun.com/xml/ns/persistence/orm"
>        Note: Both schema MUST be in the same name space due to schma
> redefine restriction.
> 
> Use cases:
> 1) application specifies orm_1_0.xsd in the orm.xml
>     - portable to other providers
>     - no openjpa specific functions allow.
> 
> 2) application specifies openjpa_orm_1_0.xsd in orm.xml
>     - only "guarantee" to work with openjpa provider.
>     - openjpa functions must be specified according to openjpa orm
> additional schema.
>     - Can use the combination of persistence.xml <provider> and
> orm.xml<entity-mappings xsi:schemaLocation=..openjpa_orm_1_0.xsd>
> stanza to enforce
> the orm must be applied using openjpa provider.
> 
>           persistence.xml
>              <persistence ....... >
>                  <persistence-unit name="MyEmployeePU">
>                      <provider>
> org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
>                       
> <mapping-file>META-INF/openjpa_orm.xml</mapping-file>
>                         ......
>           openjpa_orm.xml
>              <entity-mappings .....
>                 xsi:schemaLocation="
> http://java.sun.com/xml/ns/persistence/orm
> 
> http://incubator.apache.org/openjpa/xml/ns/persistence/openjpa
> _orm_1_0.xsd">
>                  ........
> 
> 3) No schema is specified in the orm.xml (least desirable option)
>     - openjpa functions may be added to orm.xml. OpenJPA 
> tolerates this
> option
>     - There is no validation on the stanza, hence may be 
> problematic in
> processing/handling of the stanza.
>     - No guarantee this will work in other providers.
>     - But this option is the least restrictive in orm usage
> 
> All three options are available for use by an application, in order of
> compliance and portability preferences.
> 
> Albert Lee.
> 
> On 1/24/07, Patrick Linskey <plinskey@bea.com> wrote:
> >
> > Firstly, thanks for putting this together.
> >
> > I don't think that portability is a huge problem. I agree 
> with the three
> > scenarios that Albert mentioned, but I think that we can refine #1:
> >
> > > 1) if an application wants to be fully portable between 
> providers, the
> > > standard orm.xsd must be specified. This will inhibit the use
> > > of openjpa
> > > features.
> >
> > I would revise this as follows:
> >
> > 1) if an application wants to be fully portable between 
> providers, the
> > standard orm.xsd must be specified. This will inhibit the 
> use of OpenJPA
> > features in that file, so a parallel openjpa-orm.xml file 
> must be used
> > which conforms to the OpenJPA XSD and adds the additional 
> information.
> >
> > We could even create a second XSD for that situation that 
> allows only
> > OpenJPA content to help prevent people from putting 
> conflicting stanzas
> > in the two files.
> >
> > -Patrick
> >
> > --
> > Patrick Linskey
> > BEA Systems, Inc.
> >
> > 
> ______________________________________________________________
> _________
> > Notice:  This email message, together with any attachments, 
> may contain
> > information  of  BEA Systems,  Inc.,  its subsidiaries  and 
>  affiliated
> > entities,  that may be confidential,  proprietary,  
> copyrighted  and/or
> > legally privileged, and is intended solely for the use of 
> the individual
> > or entity named in this message. If you are not the 
> intended recipient,
> > and have received this message in error, please immediately 
> return this
> > by email and then delete it.
> >
> > > -----Original Message-----
> > > From: Albert Lee [mailto:allee8285@gmail.com]
> > > Sent: Wednesday, January 24, 2007 8:38 AM
> > > To: open-jpa-dev@incubator.apache.org
> > > Subject: Re: Using query hints for mapping extensions in orm.xml
> > >
> > > First, I would not expected other providers will handle 
> the special
> > > openjpa.orm.xsd even if it is spec'ed out in the document
> > > header. If they
> > > choose to ignore the new schema and proceed to parse the
> > > document content
> > > using the standard orm.xsd, then any openjpa specific stanza
> > > will probably
> > > be flagged as non-compliance.
> > >
> > > The other scenario is: what about if the document does 
> not specify the
> > > schema at all, like the original sample. I suspect most 
> providers will
> > > tolerate this scenario, just like openjpa does.
> > >
> > > Can the solutions be:
> > > 1) if an application wants to be fully portable between 
> providers, the
> > > standard orm.xsd must be specified. This will inhibit the use
> > > of openjpa
> > > features.
> > > 2) if an application wants to use openjpa specific stanza and
> > > still be used
> > > by other provider, don't specify the schema at all in the
> > > document. Hoping
> > > the other providers will tolerate and ignore the openjpa features.
> > > 3) if an application wants to be openjpa schema 
> compliance, then use
> > > openjpa.orm.xsd in the document header and openjpa can 
> validate the
> > > document. However this will prevent the application to be
> > > portable to other
> > > providers.
> > >
> > > Albert Lee.
> > >
> > >
> > > On 1/24/07, Kevin Sutter <kwsutter@gmail.com> wrote:
> > > >
> > > > Thank you, Albert, for your experimentation.  The updated schema
> > > > definition
> > > > (openjpa_orm_1_0.xsd) and the example openjpa_orm.xml seems
> > > to be what we
> > > > are looking for.  I guess the only concern is whether we
> > > can count on
> > > > other
> > > > JPA implementations to ignore this extra schema definition
> > > and just rely
> > > > on
> > > > the standard orm.xsd.
> > > >
> > > > Question:  Even if other JPA providers are smart enough to
> > > ignore our
> > > > specialized schema and use the standard JPA schema, what
> > > happens to our
> > > > extension elements?  Do they get ignored as well?  Or, will the
> > > > verification
> > > > step still trip over these new/updated elements?
> > > >
> > > > Thanks again,
> > > > Kevin
> > > >
> > > >
> > > > On 1/23/07, Albert Lee <allee8285@gmail.com> wrote:
> > > > >
> > > > > Somehow the one of the attachment (openjpa_orm_1_0.xsd)
> > > from my previous
> > > > > note did not make it to this forum.
> > > > >
> > > > > Try again here.
> > > > >
> > > >
> > > --------------------------------------------------------------
> > > --------------------------------
> > > > >
> > > > > <?xml version="1.0" encoding="UTF-8"?>
> > > > > <!--
> > > > >     OpenJPA specific orm.xml schema locates in: (E.g.)
> > > > >
> > > > >
> > > >
> > > http://incubator.apache.org/openjpa/xml/ns/persistence/openjpa
> > > _orm_1_0.xsd
> > > > > "
> > > > >
> > > > >     This schema extends
> > > > http://java.sun.com/xml/ns/persistence/orm_1_0.xsd
> > > > > with
> > > > >         OpenJPA specific stanza and uses the same 
> name space as
> > > > >             "http://java.sun.com/xml/ns/persistence/orm"
> > > > > -->
> > > > > <xsd:schema
> > > > >                  version="1.0"
> > > > >                xmlns:xsd="http://www.w3.org/2001/XMLSchema"
> > > > >          targetNamespace="
> > > http://java.sun.com/xml/ns/persistence/orm"
> > > > >
> > > xmlns:orm="http://java.sun.com/xml/ns/persistence/orm"
> > > > >       elementFormDefault="qualified"
> > > > >     attributeFormDefault="unqualified"
> > > > >   >
> > > > >
> > > > >   <xsd:annotation>
> > > > >     <xsd:documentation>
> > > > >       @(#)openjpa_orm_1_0.xsd 1.0  Jan 22 2007
> > > > >     </xsd:documentation>
> > > > >   </xsd:annotation>
> > > > >   <xsd:annotation>
> > > > >      <xsd:documentation><![CDATA[
> > > > >
> > > > >        This is the XML Schema for extending the persistence
> > > > > object-relational
> > > > >        mapping file for OpenJPA specific features.
> > > > >
> > > > >        The file may be named "META-INF/orm.xml" in 
> the persistence
> > > > >        archive or it may be named some other name 
> which would be
> > > > >        used to locate the file as resource on the classpath.
> > > > >
> > > > >      ]]></xsd:documentation>
> > > > >   </xsd:annotation>
> > > > >
> > > > >   <!-- Redefine the orm_1_0.xsd with additional OpenJPA
> > > extensions -->
> > > > >   <xsd:redefine schemaLocation="
> > > > http://java.sun.com/xml/ns/persistence/orm_1_0.xsd
> > > > > ">
> > > > >
> > > > >     <!--
> > > > >         Append optional single <data-cache> element 
> to <entity>.
> > > > >           Valid values are "true" | "false" | "1" | "0".
> > > > >           Default value is "false".
> > > > >     -->
> > > > >     <xsd:complexType name="entity">
> > > > >       <xsd:complexContent>
> > > > >         <xsd:extension base="orm:entity">
> > > > >           <xsd:sequence>
> > > > >             <xsd:element name="data-cache" type="xsd:boolean"
> > > > > minOccurs="0" maxOccurs="1" default="false"/>
> > > > >           </xsd:sequence>
> > > > >         </xsd:extension>
> > > > >       </xsd:complexContent>
> > > > >     </xsd:complexType>
> > > > >
> > > > >
> > > > >     <!--
> > > > >         Append optional single <jdbc-nonpolymorphic> 
> element to
> > > > > <one-to-many>.
> > > > >           Valid values are "true" | "false" | "1" | "0".
> > > > >           Default value is "false".
> > > > >
> > > > >         Append optional single 
> <jdbc-eager-fetch-mode> element to
> > > > > <one-to-many>.
> > > > >           Valid values are "parallel" | "others".
> > > > >           Default value is "parallel".
> > > > >     -->
> > > > >     <xsd:complexType name="one-to-many">
> > > > >       <xsd:complexContent>
> > > > >         <xsd:extension base="orm:one-to-many">
> > > > >           <xsd:sequence>
> > > > >
> > > > >             <xsd:element name="jdbc-nonpolymorphic"
> > > type="xsd:boolean"
> > > > > minOccurs="0" maxOccurs="1" default="false"/>
> > > > >
> > > > >             <xsd:element name="jdbc-eager-fetch-mode"
> > > minOccurs="0"
> > > > > maxOccurs="1" default="parallel">
> > > > >               <xsd:simpleType>
> > > > >                 <xsd:restriction base="xsd:string">
> > > > >                   <xsd:enumeration value="parallel"/>
> > > > >                   <xsd:enumeration value="others"/>
> > > > >                 </xsd:restriction>
> > > > >               </xsd:simpleType>
> > > > >             </xsd:element>
> > > > >
> > > > >           </xsd:sequence>
> > > > >         </xsd:extension>
> > > > >       </xsd:complexContent>
> > > > >     </xsd:complexType>
> > > > >
> > > > >   </xsd:redefine>
> > > > >
> > > > > </xsd:schema>
> > > > >
> > > > >
> > > > > Albert Lee
> > > > >
> > > >
> > > >
> > >
> >
> 

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