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

III-COR：合作研究：信息系统中的优雅演化和历史演进--统一方法数据库模式演化代表了信息系统生命周期中的一个常数，并且是维护、升级和服务停机时间的主要成本的来源。传统的模式修订过程依赖于新模式的安装，沿着安装修订的数据库，以及一组经过转换的应用程序（经过艰苦的重写以使用此模式）。相反，该项目开发了新的使能技术，使模式演变的问题减少到协调多个并发版本的模式，应用程序和数据库之间的映射。这是通过元管理器系统实现的，元管理器系统提供了对演进的（i）数据和（ii）元数据的集成管理，并有效地支持（iii）映射和（iv）优雅模式演进所需的软件工件。此外，元管理器允许保存和查询数据库历史，同时它帮助用户计划如何用“如果”演变场景来演变当前模式版本。该系统的功能和性能使用各种测试平台进行验证，例如圣地亚哥超级计算中心的存储请求代理，该代理为从天体物理学家到生物学家的各种研究小组托管科学数据。这种新颖而及时的方法为信息系统的演化和保存提供了统一的解决方案。由于信息系统所起的关键作用，广泛的科学、教育和经济活动将从这些进步中受益。结果通过出版物、报告和演示进行传播，可从以下项目网站获得：http://www.cs.ucr.edu/~tsotras/meta-manager http://wis.cs.ucla.edu/projects/meta-manager http://db.ucsd.edu/people/alin/meta-manager

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