Managing and querying transaction-time databases under schema evolution

The old problem of managing the history of database information is now made more urgent and complex by fast spreading web information systems, such as Wikipedia. Our PRIMA system addresses this difficult problem by introducing two key pieces of new technology. The first is a method for publishing the history of a relational database in XML, whereby the evolution of the schema and its underlying database are given a unified representation. This temporally grouped representation makes it easy to formulate sophisticated historical queries on any given schema version using standard XQuery. The second key piece of technology is that schema evolution is transparent to the user: she writes queries against the current schema while retrieving the data from one or more schema versions. The system then performs the labor-intensive and error-prone task of rewriting such queries into equivalent ones for the appropriate versions of the schema. This feature is particularly important for historical q...

• Type: Journal
• Year: 2008
• Where: PVLDB
• Authors: Hyun Jin Moon, Carlo Curino, Alin Deutsch, Chien-Yi Hou, Carlo Zaniolo
• Keywords: Key Piece, PVLDB 2008, Schema Evolution, Schema Versions