Hi Erik, OK now I got it, you want to support fields within the same PC class to be persisted to different datasources, right?
Erik Bengtson schrieb: > Jorg, > > An example: > > Class product > > Field name ; //oracle > Field price ; //erp > Field instock ; //erp > > With multiple databases feature, you can load an object distributed in > multiples databases. As Eric said we will not reinvent JTA. > > Each implementation can use JTA to support transactions with multiple > datasources, but can use any other mechanism (not defined). JPOX is pluggable > and enabled to accept any jta implementation. > > If you don't provide an external jta implementation, JPOX will use its > internal implementation. > -- BlackBerry® from Mobistar --- > > -----Original Message----- > From: Joerg von Frantzius <[EMAIL PROTECTED]> > > Date: Mon, 05 Nov 2007 10:28:55 > To:[email protected] > Cc:[EMAIL PROTECTED] > Subject: Re: multiple databases one PM/TX > > > Hi Erik, > > there is one thing that I don't understand about this proposed feature > (which may be just me not seeing the obvious point of course :) > > Running 2PC on multiple data sources is handled already by J2EE > implementations, and, as far as I recall, there are also libraries > available that provide a JTA without a full blown J2EE server. Why would > you want to duplicate this already existing and available functionality > in JDO? > > Regards, > Jörg > > Erik Bengtson schrieb: > >> In JPOX we are implementing the access to multiple datastores within a single >> PM/TX. If not too late, I’m wonder if you like to hear a proposal to >> standardize the configuration of the “jdoconfig” and jdo metadata to be able >> to >> handle this scenario. It may sound overkill, but IMO is a major advance over >> JPA. >> >> To introduce the subject, the goal is to handle persistence in multiple >> databases (e.g. derby, oracle, DB4O, Versant, XML) within a single JDO >> transaction/ single PM. From the user point of view, there are two items that >> must be configured, jdo metadata, jdo configuration, in which would be part >> of >> this proposal, so I show below an example of the configurations: >> >> /jdoconfig/ sequence unbounded PMF >> /jdoconfig/ sequence unbounded Resource >> >> /PMF/ >> /PMF/@Class >> /PMF/@TransactionTimeout >> /PMF/@... >> /Resource/ >> /Resource/@Name >> /Resource/Connection Settings/ >> /Resource/Connection Settings/@ConnectionFactoryName >> /Resource/Connection Settings/@ConnectionClientID >> /Resource/Connection Settings/@ReadOnly >> /Resource/Connection Settings/@... >> /Resource/Transaction/ >> /Resource/Transaction/@TwoPhaseCommit >> /Resource/Transaction/@Timeout >> >> ConnectionClientID >> ---------------------------- >> ConnectionClientID is the identifier for the connection. Some databases such >> as >> Oracle use this to identify the end user (not the connection user). >> ConnectionClientID would accept the values: >> >> 1 - CredentialMapping - the CredentialMapping takes the principal of the >> running >> application and sets it as client id - eg. >> ConnectionClientID=CredentialMapping >> 2 - Identity – the client id is taken from the id right after the Identity >> word >> - eg. ConnectionClientID=Identity:MyUser >> >> ReadOnly >> ---------------------------- >> ReadOnly (accepts true, false) will block write operations to this connection >> >> TwoPhaseCommit >> -------------------------- >> Two options: >> >> 1 – LastLoggingResource - If the resource is non XA, push down this resource >> in >> commit order. >> 2 – Emulated – Emulates non XA protocol. Heuristics errors could happen >> >> Example: >> >> <jdoconfig> >> >> <pmf name=”snowdog” default-resource=”Oracle”> >> </pmf> >> >> <resource name=”ERP”> >> <connection connectionfactoryname=”BSCS_Hot”/> >> </resource> >> >> <resource name=”PeopleSoft”> >> <connection connectionfactoryname=”PS_Onyx”/> >> </resource> >> >> <resource name=”Oracle”> >> <connection connectionfactoryname=”ORA_Vinci” >> connection-client-id=”CredentialMapping”/> >> <transaction two-phase-commit=”LLR” timeout=”30”/> >> </resource> >> >> <resource name=”Xml”> >> <connection readonly=”true”/> >> <extension> >> <jpox:xml file=”file:/usr/home/myxml.xml”/> >> </extension> >> </resource> >> >> >> </jdoconfig> >> >> <jdo> >> <package> >> <class name=”Invoice” resource=”ERP”/> >> <class name=”ClassData”/> <!-- uses default-resource --> >> <class name=”Person” resource=”PeopleSoft”/> >> <class name=”ReferenceData” resource=”Xml”/> >> </package> >> </jdo> >> >> >> >> >> Quoting Michelle Caisse <[EMAIL PROTECTED]>: >> >> >> >>> Hi, >>> >>> We will have our regular meeting Friday, October 26 at 9 am PDT to >>> discuss JDO TCK issues and status. >>> >>> Dial-in numbers are: >>> 866 230-6968 294-0479# >>> International: +1 865 544-7856 >>> >>> Agenda: >>> >>> 1. Subquery spec update >>> 2. Other issues >>> >>> Action Items from weeks past: >>> >>> [Oct 12 2007] AI Michael take a look at subquery tck tests. >>> https://issues.apache.org/jira/browse/JDO-446 >>> >>> [Sep 14 2007] AI Matthew provide examples for 8.6.1.1 jdoconfig.xml. >>> >>> [June 22 2007] AI Craig discuss svn:eol-style on email. >>> >>> [June 22 2007] AI Craig write a proposal on annotation overrides for >>> the expert group. >>> >>> [May 25 2007] AI everyone Download the Grails demo from grails.org and >>> check it out. Also look at Grails/Groovy ExpandoMetaClass that has the >>> magic to avoid reflection and enhancement. >>> >>> [May 25 2007] AI Matthew Adams prepare a proposal with just the basics >>> of schema synchronization with jdo and orm metadata. >>> >>> [May 18 2007] AI Craig update http://wiki.apache.org/jdo/ >>> CurrentDevelopment wiki page >>> >>> [Apr 27 2007] AI Craig review Query API and send email to experts. >>> >>> [Apr 27 2007] AI Erik file a JIRA regarding JPA style transactions and >>> attach his discussion document to it. >>> >>> [Mar 9 2007] AI Craig: Update the spec to require that the key of the >>> listener is the class name of the listener, for consistency with >>> proposed xml.. >>> >>> [Mar 2 2007] AI Craig: update the JDOHelper class to include a string >>> constant "META-INF/jdo.xml" and a new method >>> getPersistenceManagerFactory taking no arguments. >>> >>> [Aug 11 2006] AI Craig propose some semantics for behavior if user >>> tries to add to a list where the ordering element is incorrect. >>> >>> [Jul 14 2006] AI: Erik document 220 annotations that don't have a >>> corresponding JDO concept. >>> >>> [Jun 23 2006] AI Martin look at what Hibernate and TopLink support >>> for Enum types. In progress. >>> >>> [Apr 14 2006] AI Craig: update the roadmap for JDO. In progress. >>> >>> [Nov 4 2005] AI Martin: Update Martin's wiki with discusion of JDK 1.5 >>> issues. In progress >>> >>> [Sep 2 2005] AI: To recruit members, update the web site. Articles on >>> TheServerSide directing attention to the site. T-shirts, logo. AI: >>> Craig write a ServerSide article. >>> >>> -- Michelle >>> >>> >>> >> >> >> >> >> > > >
