Xref: utzoo comp.object:3553 comp.databases:10202 Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!tut.cis.ohio-state.edu!sei.cmu.edu!fs7.ece.cmu.edu!o.gp.cs.cmu.edu!netnews.srv.cs.cmu.edu!clamen From: clamen@CS.CMU.EDU (Stewart Clamen) Newsgroups: comp.object,comp.databases Subject: Re: Schema/Type Evolution in Traditional and O-O DBMSs Message-ID: Date: 21 May 91 21:32:07 GMT References: Sender: netnews@cs.cmu.edu (USENET News Group Software) Reply-To: clamen+@CS.CMU.EDU Organization: School of Computer Science, Carnegie Mellon University Lines: 61 In-Reply-To: clamen@CS.CMU.EDU's message of 5 May 91 21:48:01 GMT In article I made the following request: I am doing research in the area of type evolution in databases (object-oriented databases in particular) and wish to learn a bit more about how existing systems deal with the problem. I'd much appreciate it if those readers with intimate knowledge of a particular DBMS or OODBMS would drop me a note telling me if and how the system provides support for the evolution of types. By "type evolution", I am referring to the process of redefining an existing type (or schema in database parlance) in a DBMS and provisions for the reformatting of the data representing the instances of that type present in the database prior to the redefinition. I am already familiar with the services provided by ORION and GemStone. I have so far, received relevant information now on the following systems: Research Systems Commercial Systems ---------------- ----------------- ORION Symbolics' Statice IRIS Versant GemStone Object Design Encore Objectivity COOL/COCOON ObjectStore Exodus Ontos (formerly VBase) Machiavelli NMP-CAD's Base/OPEN ConceptBase PICK AVANCE Persistent Data Systems' IDL products Before I consider my survey complete, and post what I have collected to the net (and mailed it to those who so requested), I'd like to make a directed request for schema evolution and database conversion as it pertains to other particular systems I have read about. As you might have noticed, most of these systems are OODBMS. I am interested in learning about the more traditional DBMSs, as well as other non-OO systems. Notably: ADAPLEX CODASYL CLASSIC DAPLEX POSTGRES I would also like to hear something about Altair/O_2, an OODB project in France. Thank you again. -- Stewart M. Clamen Internet: clamen@cs.cmu.edu School of Computer Science UUCP: uunet!"clamen@cs.cmu.edu" Carnegie Mellon University Phone: +1 412 268 3620 Pittsburgh, PA 15213-3890, USA Fax: +1 412 268 1793