Hi Jörg, On Jul 22, 2008, at 8:13 AM, Joerg von Frantzius wrote:
Hi,when calling PersistenceManager.getObjectById() with a SingleFieldIdentity, there seems to be no way of avoiding the following (if the implementation decides to do so):"It is an implementation decision whether to access the data store, if required to determine the exact class. This will be the case of inheritance, where multiple <code>PersistenceCapable</code> classes share the same ObjectId class."Now when I know for sure that the targetClassName of the given SingleFieldIdentity already denotes the correct class for the given id, how can I avoid that additional roundtrip to the database for finding the exact class?
The behavior of getObjectById might better be determined by the object id itself instead of the programmer having to know whether the class is the exact class.
Maybe we should look at another constructor for the SingleFieldIdentity classes that embeds the knowledge that the class name is exact? That way, the jdo implementation could construct identity instances and the user could also construct identity instances that represent the exact class.
WDYT? Craig
Maybe it would be useful to have anotherObject getObjectById (Object oid, boolean validate, boolean determineExactClassInDatastore);on PersistenceManager for that purpose? Regards, Jörg -- ____________________________________________________________________ artnology GmbH - Milastraße 4 - 10437 Berlin - Germany Geschäftsführer: Ekkehard Blome (CEO), Felix Kuschnick (CCO)Registergericht: Amtsgericht Berlin Charlottenburg HRB 76376 UST-Id. DE 217652550
Craig L 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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