object-oriented

An introduction to schema versioning in OODBMS

Authors: 
Lautemann, SE
Year: 
1996
Venue: 
Proc. 7th Int. Workshop on Database and Expert Systems Applications (DEXA)

Object oriented database management systems (OODBMS) have enormous advantages in comparison to relational systems in modeling highly complex and dynamic application scenarios. Still they lack some flexibility which could help their promotion into widely spread industrial use. Especially engineering environments frequently require schema changes to handle evolving designs. The main contribution of the paper is twofold: firstly, we give an overview of schema evolution mechanisms, describing the state of the art in research.

Schema evolution in OODBs using class versioning

Authors: 
Monk, S; Sommerville, I
Year: 
1993
Venue: 
ACM SIGMOD Record

Implementing Lazy Database Updates for an Object Database System

Authors: 
Ferrandina, F; Meyer, T; Zicari, R
Year: 
1994
Venue: 
Proc. 20th VLDB, 1994

Current object database management systems support user-defined conversion functions to update the database once the schema has been modified. Two main strategies are possible when implementing such database conversion functions: immediate or lazy database updates. In this paper, we concentrate our attention to the definition of implementation strategies for conversion functions implemented as lazy database updates.

A Survey of Schema Evolution in Object-Oriented Databases

Authors: 
Li, Xue
Year: 
1999
Venue: 
TOOLS 1999

Changes in the real world may require both the database population and the database schema
to evolve. Particularly, this is the case in CAD/CAM and CASE database systems, in which the
design objects constantly evolve in every aspect. On the other hand, the prototyping of a
database design may also involve changes to both the structure and behavior of a schema.
Unfortunately, most of the current systems offer little support for schema evolution. In this
paper, we survey the recent development of the research in the schema evolution of objectoriented

A Model for Compound Type Changes Encountered in Schema Evolution

Authors: 
Lerner, B. S.
Year: 
2000
Venue: 
TODS 2000

Schema evolution is a problem that is faced by long-lived data. When a schema changes, existing persistent data can become inaccessible unless the database system provides mechanisms to access data created with previous versions of the schema. Most existing systems that support schema evolution focus on changes local to individual types within the schema, thereby limiting the changes that the database maintainer can perform. We have developed a model of type changes involving multiple types.

An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems

Authors: 
Peters, Randel J.; Özsu, M. Tamer
Year: 
1997
Venue: 
ACM TODS 22(1): 75-114 (1997)

A sound and complete axiomatic model is proposed for dynamic schema evolution (DSE) in objectbase systems (OBSs) that supports the fundamental concepts of object-oriented computing such as subtyping and property inheritance. The model can infer all schema relationships from two identified input sets associated with each type called the essential supertypes and essential properties. These sets are typically specified by schema designers but can be automatically supplied within an OBS. The inference mechanism performed by the model has a proven termination.

Schema Transformation without Database Reorganization

Authors: 
Tresch, Markus; Scholl, Marc H.
Year: 
1993
Venue: 
Sigmod Record, 1993

We argue for avoiding database reorganizations due to schema modification in object-oriented systems, since these are expensive operations and they conflict with reusing existing software components. We show that data independence, which is a neglected concept in object databases, helps to avoid reorganizations in case of capacity preserving and reducing schema transformations. We informally present a couple of examples to illustrate the idea of a schema transformation methodology that avoids database reorganization.

A Transparent Schema-Evolution System Based on Object-Oriented View Technology

Authors: 
Ra, Y.; Rundensteiner, E.
Year: 
1997
Venue: 
IEEE Trans.Knowledge and Data Engineering

When a database is shared by many users, updates to the database schema are almost always prohibited because there is a risk of making existing application programs obsolete when they run against the modified schema. This paper addresses the problem by integrating schema evolution with view facilities. When new requirements necessitate schema updates for a particular user, then the user specifies schema changes to his personal view, rather than to the shared-base schema.

Schema and Database Evolution in the O2 Object Database System

Authors: 
Ferrandina, Fabrizio; Meyer, Thorsten; Zicari, Roberto; Ferran, Guy; Madec, Jolle
Year: 
1995
Venue: 
VLDB 1995

When the schema of an object-oriented database system
is modified, the database needs to be changed in
such a way that the schema and the database remain
consistent with each other. This paper describes the
algorithm implemented in the new forthcoming release
of the O2 object database for automatically bringing the
database to a consistent state after a schema update has
been performed. The algorithm, which uses a deferred
strategy to update the database, is a revised and extended
version of the screening algorithm first sketched in [7].

Management Of Schema Evolution In Databases

Authors: 
Andany, J.; Lonard, M.; Palisser, C.
Year: 
1991
Venue: 
VLDB 1991

This paper presents a version model which handles database schema changes and which takes evolution into account. Its originality is in allowing the development of partial schema versions, or views of a schema. These versions are created in the same database from a common schema. We define the set of authorised modifications on a schema and the rules which guarantee its coherence after transformation. Mechanisms allowing data to be associated with each version are also integrated in the model.

Semantics and implementation of schema evolution in object-oriented databases

Authors: 
Banerjee, J.; Kim, W.; Kim, H.; Korth, H. F.
Year: 
1987
Venue: 
Proc. Sigmod 1987

Object-oriented programming is well-suited to such data-intensive application domains as CAD/CAM, AI, and OIS (office information systems) with multimedia documents. At MCC we have built a prototype object-oriented database system, called ORION. It adds persistence and sharability to objects created and manipulated in applications implemented in an object-oriented programming environment. One of the important requirements of these applications is schema evolution, that is, the ability to dynamically make a wide variety of changes to the database schema.

Versions of Schema for Object-Oriented Databases

Authors: 
Kim, W.; Chou, H.
Year: 
1988
Venue: 
Proc. 14th VLDB, 148-159.

Version control is one of the important database require-
ments for design environments. Various models of ver-
sions have been proposed and implemented. However,
research in versions has been focused exclusively on
versioning single design objects. In a multi-user design
environment where the schema (definition) of the design
objects may undergo dynamic changes, it is important to
be able to version the schema, as well as version the
single design objects. In this paper, we propose a model
of versions of schema by extending our model of versions

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