Data Consistency of a Decision Support System at Distributed Database

Abstract

Warehousing for a decision support is a technique for retrieval and integration of data from distributed, autonomous, possibly heterogeneous, information sources. A data warehouse collects integrated information, available for queries and analysis. A materialized view of the system is kept at a site called the data warehouse, and user queries are processed using this view. The view has to be maintained to reflect the updates done against the base relations stored at the various data sources. A more efficient solution to be reflected updates done at each source is to materialize the relevant subsets of the data at the base relations pertaining to the actual view and process user queries against this local data. The updates done against the base relations are propagated to the materialized view and the view is maintained incrementally. However, earlier algorithms for incremental view maintenance either required a quiescent state at the data warehouse or required exponential message amounts in terms of the data sources. Therefore, in this paper, we proposed an enhanced algorithm and the algorithm instead does not require that the data warehouse be in a quiescent state for incorporating the new views and also the message amount between warehouse and sources can be reduced.