Path: utzoo!utgpu!watmath!att!bellcore!texbell!wuarchive!wugate!uunet!odi!dlw From: dlw@odi.com (Dan Weinreb) Newsgroups: comp.databases Subject: Re: Extended RDB vs OODB Message-ID: <1989Aug17.152708.27900@odi.com> Date: 17 Aug 89 15:27:08 GMT References: <3560052@wdl1.UUCP> <408@odi.ODI.COM> <3324@rtech.rtech.com> <1989Aug11.143036.24703@odi.com> <1765@ethz.UUCP>Reply-To: dlw@odi.com Organization: Object Design, Inc. Lines: 68 In-reply-to: cimshop!davidm@uunet.UU.NET's message of 17 Aug 89 00:32:58 GMT In article cimshop!davidm@uunet.UU.NET (David S. Masterson) writes: The one flaw in this request is that proof of concept can't be provided if the concept hasn't been defined. I agree with Jon Krueger in that there is too much hand-waving in this discussion ("our system is better than yours") without defining the problem that is trying to be met. Indeed. This cannot be emphasized strongly enough. The term "object-oriented database system" is currently being used by a fairly large number of research and product development groups. It's clear from the published literature that the term covers quite a lot of ground. Some of these systems have things in common with others in some respects, while differing greatly in other respects. I have been at least as guilty as anyone of adding to the confusion, with my recent postings, and I apologize for not being more specific and clear. While I have been following the research reports of quite a few different groups and consider many of them very interesting, my own attention has (naturally) been focused on the specific product that I'm working on at Object Design. It's only one of a vast range of approaches that can legitimatly call themselves "object-oriented database systems". In the future, I will be more explicit about what I'm referring to. There's no official definition of "object-oriented database systems". Various groups of people have proposed definitions and criteria, but naturally there is no particular group that is obviously qualified to rule on a universal definition for the whole database community. Anyone who wants to get a better sense of the diversity of the field, and also get an overall feeling for what kinds of things are being worked on, might want to read: The Proceedings of the 1986 International Workshop on Object-Oriented Database Systems, edited by Dittrich and Dayal, ACM order number 472861, ISBN 0-8186-0734-3, IEEE Computer Society Order Number 734. 235 pages. Proceedings of the 1989 ACM SIGMOD, also published as SIGMOD Record Vol 18, No. 2, June 1989. There are six papers in the two sessions on object-oriented databases, reasonably representative of the latest work in the area. Much other interesting work has appeared in the SIGMOD proceedings of the last five years. ACM Transactions on Office Information Systems, Vol. 5, No. 1, Jan 87, Special Issue On Object-Oriented Systems. This special issue contains five extensive articles about five research efforts in object-oriented database systems, all different. The articles have extensive references, through which the interested reader can find a wealth of related material. Also, all three proceedings of the OOPSLA conference have interesting papers on the topic. ACM Computing Surveys, Vol. 19, No. 2, June 1987 has an excellent and extensive article called "Types and Persistence in Database Programming Languages", by Atkinson and Buneman. It discusses the question of integration of languages with database systems, which is of great interest to some, but not all, of the object-oriented database efforts. ACM Computing Surveys, Vol. 19, No. 3, Sept 1987 has another excellent and extensive article, this one called "Semantic Database Modelling: Survey, Applications, and Research Issues" by Hull and King. Semantic database models have some relationship to object-oriented database models, although what the relation consists in is something of a topic of debate. Nonetheless, I think the article is practically required reading for anyone who intends to work on object-oriented database systems.