An algebraic formulation of the aggregative closure query

AbstractThe aggregative closure problem, a transitive closure problem with aggregations on transitive paths, is formally defined by database terms. Its definition in our paper holds only on the subset conditions of path algebra, thereby it is more general than other definitions in previous works. For the completion of the definition, we suggest conditions for the existence of the fixpoint and classified the conditions as the properties of the aggregate operators and the problem domain. So we can verify the existence of the fixpoint by the suggested conditions. The naive algorithm is proposed as a computational semantics for the aggregative closure problem. This study also proves that for an aggregative closure problem the semi-naive algorithm is computationally equivalent to the naive algorithm when the aggregate product operator is distributive over aggregate sum operator

A DATABASE INTEGRATION SYSTEM BASED ON GLOBAL VIEW GENERATION

Abstract: Database integration is a common and growing challenge with the proliferation of database systems, data warehouses, data marts, and other OLAP systems in organizations. Although there are many methods of sharing data between databases, true interoperability of database systems requires capturing, comparing, and merging the semantics of each system. In this work, we present a database integration system that improves on the database federation architecture by allowing domain administrators to simply and efficiently capture database semantics. The semantic information is combined using a tool for producing a global view. Building the global view is the bottleneck in integration because there are few tools that support its construction, and these tools often require sophisticated knowledge and experience to operate properly. The technique and tool presented is simple and powerful enough to be used by all database administrators, yet expressive enough to support the majority of integration queries.