Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!ginosko!uunet!cimshop!davidm From: cimshop!davidm@uunet.UU.NET (David S. Masterson) Newsgroups: comp.databases Subject: Re: Extended RDB vs OODB Message-ID: Date: 18 Aug 89 22:32:38 GMT References: <3560052@wdl1.UUCP> <408@odi.ODI.COM> <3324@rtech.rtech.com> <1989Aug11.143036.24703@odi.com> <1765@ethz.UUCP> <5259@wiley.UUCP> <1989Aug17.211534.28345@odi.com> Sender: davidm@cimshop.UUCP Organization: Consilium Inc., Mountain View, California. Lines: 18 In-reply-to: jack@odi.com's message of 17 Aug 89 21:15:34 GMT Based on Jack Orenstein's message, I have a couple of questions: 1. In implementing an OODB on top of C++ using the notion of persistent and transient type objects, when you refer to information in the OODB, is it always by an object identifier? How, therefore, would you find objects meeting some qualification if you don't know its identifier? Is this even a type of query you would ask in an OODB world? (you ALWAYS know the identifier because even a qualification would be wrapped in an object which contains the identifier?) 2. Again using the architecture of persistent and transient objects, is a persistent object ever in memory? Or is it just a transient copy of a persistent object that is in memory? Then, how are persistent objects created? David Masterson uunet!cimshop!davidm 415-691-6311