This article is from the Object-Oriented Technology FAQ, by Bob Hathaway firstname.lastname@example.org with numerous contributions by others.
Entry on schema evolution only:
*Ontos provides schema evolution. It allows any class to be modified.
*The major drawback is that data does not migrate ie., instances are
*not modified to adopt to the new class definition. So schema changes
*can be done only on classes that do not contain instances and do not
*have sub classes that contain instances.
*As a system for experiments, we are currently using ONTOS from
*Ontologic Inc. Unfortunately, there is no transparent concept of
*schema evolution for populated database. Thus, we still investigate
*how it works.
ONTOS, Inc. provides object-oriented products and services that enable
users to integrate, distribute, and manage information across the
Product Overview: The ONTOS Virtual Information Architecture (ONTOS VIA)
is a strategy for integrating an organization's disparate information
resources. It includes a set of products for developing and deploying
distributed, network-based applications and for accessing information
stored in a variety of formats. ONTOS VIA allows organizations to take
advantage of new technologies while preserving existing technology
The products that make up ONTOS VIA include ONTOS DB, a fully distributed
Component Object Database and ONTOS Object Integration Server (ONTOS
OIS), which provides object access to relational and mainframe databases.
ONTOS products are available on UNIX and Microsoft operating environments.
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