Efficient Transaction Management Query Processing in Massive Digital Databases

We address several important issues that arise in the development of Massive Digital Database Systems (MDDSs) in which data is being added continuously and on which users pose queries on the fly. News-on-demand and document retrieval systems are examples of systems that have these characteristics. Given the size of data, metadata such as index structures become even more important in these systems --- data is accessed only after processing the metadata, both of which will reside on tertiary storage. The focus of this paper is on query and transaction processing in such systems, with emphasis on metadata management. The performance in these systems can be measured in terms of the response time for the queries and the recency or age of the items retrieved. Both need to be minimized. The key to satisfying the performance requirements is to exploit the characteristics of the metadata as well as of the queries and updates that access the metadata. After analyzing the functionality and correctness..