See also Appendices B and E and the comp.database.object newsgroup. Refs to be included in future FAQs.
Object-Oriented Databases are databases that support objects and classes. They are different from the more traditional relational databases because they allow structured subobjects, each object has its own identity, or object-id (as opposed to a purely value-oriented approach) and because of support for methods and inheritance. It is also possible to provide relational operations on an object-oriented database. OODBs allow all the benefits of object-orientation, as well as the ability to have a strong equivalence with object-oriented programs, an equivalence that would be lost if an alternative were chosen, as with a purely relational database.
Another way of looking at Object-Oriented Databases is as a persistent object store with a DBMS.
Persistence is often defined as objects (and their classes in the case of OODBs) that outlive the programs that create them. Object lifetimes can be viewed as a hierarchy, with locals/automatics having the shortest default lifetime and objects stored indefinitely in an OODB (which are persistent) having the longest. Persistent object stores do not support query or interactive user interface facilities, as found in a fully supported OODBMS.
Appendix B also contains references for object-oriented interfaces to relational databases and see APPENDIX E, Papers, Persistent Operating Systems.
From the net: From: email@example.com (DBMSfacts) Subject: ODMG Gopher and Web Addresses Date: 24 Oct 1994 13:10:02 -0400
The Object Database Management Group (ODMG) has set up Gopher and Web Servers at the following addresses:
Gopher: gopher.odmg.org, port 2073 WWW: http://www.odmg.org:3083
These are still under construction. What you can find right now are addresses and contact information for ODBMS vendors, ODMG membership information, updates to Release 1.1 of The Object Database Standard: ODMG-93 along with ODL lex and yacc files. In the future, we will be adding more links to related sites, bibliographies, and a FAQ for ODBMSs.
If you cannot access these servers, but would like information on the ODMG, send an email message to firstname.lastname@example.org and you will receive an automated reply.
Doug Barry ODMG Executive Director
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