III-COR: Collaborative Research: Graceful Evolution and Historical Queries in Information Systems--a Unified Approach

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

III-COR: Collaborative Research: Graceful Evolution and Historical Queries in Information Systems-- a Unified Approach Database schema evolution represents a constant in the life cycle of Information Systems, and is the source of major costs for maintenance, upgrading, and service down time. The traditional schema revision process depends on the installation of a new schema along with the revised database, and a converted set of applications (laboriously rewritten to work with this schema). Instead, this project develops the novel enabling technology whereby the schema evolution problem is reduced to coordinating mappings between multiple concurrent versions of the schema, applications, and the database. This is realized by the Meta-Manager system which provides integrated management of evolving (i) data, and (ii) metadata, and efficiently supports the (iii) mappings, and (iv) software artifacts needed for graceful schema evolution. Further, the Meta-Manager allows for preservation and querying of database history while it assists the user in planning how to evolve the current schema version with ``what-if'' evolution scenarios. The functionality and performance of the system is validated using various testbeds, such as, the San Diego Supercomputing Center's Storage Request Broker, which hosts scientific data for various research groups ranging from astrophysicists to biologists. This novel and timely approach provides a unified solution to both the evolution and preservation of information systems. Because of the key role played by information systems, a broad range of scientific, educational, and economic activities will benefit from these advances. Results are disseminated via publications, reports and demos available from the project web sites: http://www.cs.ucr.edu/~tsotras/meta-manager http://wis.cs.ucla.edu/projects/meta-manager http://db.ucsd.edu/people/alin/meta-manager