Special report: the 1988 Object-oriented database workshop
ACM SIGMOD Record
SIGMOD '91 Proceedings of the 1991 ACM SIGMOD international conference on Management of data
Introduction to object-oriented databases
Introduction to object-oriented databases
SIGMOD '93 Proceedings of the 1993 ACM SIGMOD international conference on Management of data
EDBT '94 Proceedings of the 4th international conference on extending database technology: Advances in database technology
The MultiView OODB view system: design and implementation
Theory and Practice of Object Systems - Special issue on subjectivity in object-oriented systems
The MultiView project: object-oriented view technology and applications
SIGMOD '96 Proceedings of the 1996 ACM SIGMOD international conference on Management of data
A Transparent Schema-Evolution System Based on Object-Oriented View Technology
IEEE Transactions on Knowledge and Data Engineering
A Transparent Object-Oriented Schema Change Approach Using View Evolution
ICDE '95 Proceedings of the Eleventh International Conference on Data Engineering
Using Object-Oriented Principles to Optimize Update Propagation to Materialized Views
ICDE '96 Proceedings of the Twelfth International Conference on Data Engineering
Versions of Schema for Object-Oriented Databases
VLDB '88 Proceedings of the 14th International Conference on Very Large Data Bases
Multiview: A Methodology for Supporting Multiple Views in Object-Oriented Databases
VLDB '92 Proceedings of the 18th International Conference on Very Large Data Bases
Unified Class Evolution by Object-Oriented Views
ER '92 Proceedings of the 11th International Conference on the Entity-Relationship Approach: Entity-Relationship Approach
Consistent View Removal in Transparent Schema Evolution Systems
RIDE '96 Proceedings of the 6th International Workshop on Research Issues in Data Engineering (RIDE '96) Interoperability of Nontraditional Database Systems
Consistent Schema Version Removal: An Optimization Technique for Object-Oriented Views
IEEE Transactions on Knowledge and Data Engineering
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Powerful interoperability-enabling solutions for software application integration must allow applications to evolve and data requirements to change, while minimizing such changes on other integrated applications. Thus, we have developed the transparent schema evolution (TSE) system that accomplishes evolution by generating a new object-oriented view schema to capture the changes desired by the user, while preserving existing view schemas for old applications. This generation of a potentially large number of schema versions over time results in an excessive build-up of classes and underlying object instances - some of which may no longer be in use. The presence of no-longer-utilized view schemas will result in storage overhead costs and a degradation of system performance due to the update propagation of our materialized view foundation. In this paper, we address this problem using consistent schema removal techniques. Our solution is based on a formal model of capturing all dependencies between classes as logic clauses and of manipulating them to make decisions on class deletions and nondeletions while guaranteeing the consistency of the schema. Based on this formal model, we have developed and proven consistent a dependency graph (DG) representation and associated set of rules for DG generation, reduction, and transformation. The later has been successfully implemented in our TSE optimizer tool. To address the problem that view schema removal is sensitive to the order in which individual classes are processed, we present a cost model for evaluating alternative removal patterns on DG. We also report our preliminary experimental studies that validate our approach and demonstrate its impact on the performance of the TSE system.