Schema Evolution publication categorizer

Dynamic schema evolution is the ability of the database schema to evolve by incorporating changes to its structure without loss of existing data and without significantly affecting the day-to-day operations of the database. A very large body of literature exists today reflecting the extensive work addressing schema evolution and its management. Schema evolution has three well-defined and inter-related activities: core schema evolution, version management, and application management. These activities have been examined using different databases and associated data models – the object-oriented, relational, and semantic data models. The first objective of this paper is to examine schema evolution research and present a comprehensive summary of the different research activities from both perspectives. Researchers have examined schema evolution in single stand-alone databases and schema evolution in an integrated heterogeneous set of databases has received little attention. Such systems are common in organizations either as part of large information systems or in data warehouses. The second objective is to highlight the importance of schema evolution in heterogeneous database systems. Managing schema evolution in heterogeneous database systems is much more complicated than in single standalone databases and may therefore require automated support. The third objective is to critically examine the implications for automating schema evolution.