This paper discusses the incremental maintenance of materialized ontologies in a rule-enabled Semantic Web. Materialization allows to speed up query processing by explicating the implicit entailments which are sanctioned by the semantics of an ontology. The complexity of reasoning with the ontology is thereby shifted from query time to update time. We assume that materialization techniques will...

Materialization is a powerful and ubiquitous abstraction pattern for conceptual modeling that relates a class of categories (e.g., models of cars) and a class of more concrete objects (e.g., individual cars). This paper presents materialization as a generic relationship between two classes of objects and describes an abstract implementation of it. The presentation is abstract in that it is not ...

Abstract. The issues of performance, response efficiency and data consistency are among the most important ones for data intensive Web sites on the Internet today. In order to deal with these issues we analyze and evaluate a materialization policy that may be applied to data intensive Web sites. Our research relies on the performance evaluation of experimental client/server configurations. We p...

The View Generator (VG) is a system that provides the necessary components for the definition, materialization, storage, maintenance and re-use of views over remote web-accessible databases. Through the system, clients identify web databases of interest, access their metadata and create personalized views that can be shared by other clients. Creating personalized views provides a more efficient...

Due to the limitation of computing and storage resources, online analysis of massive data is usually time consuming. Data cube materialization is an effective way to improve the performance of online analysis. Considering the potential parallelism of genetic algorithm and its good global searching ability, a materialization method of data cube based on genetic algorithm is proposed. This method...

ÐWith a huge amount of data stored in spatial databases and the introduction of spatial components to many relational or object-relational databases, it is important to study the methods for spatial data warehousing and OLAP of spatial data. In this paper, we study methods for spatial OLAP, by integration of nonspatial OLAP methods with spatial database implementation techniques. A spatial data...

ABS’I IiACT __ ___...l The traditional Query Modification appi oa(. h to query processing is inappropriate for views involving generalization. We use a combination of modification and materialization for queries over such isiews. Furthermore, by choosing modification or materialization ae part of global optimization, we permit more optimization than would be provided by a purely modifying appro...

A Data Warehouse (DW) can be abstractly seen as a set of materialized views de ned over relations that are stored in distributed heterogeneous databases. The selection of views for materialization in a DW is thus an important decision problem. The objective is the minimization of the combination of the query evaluation and view maintenance costs. In this paper we expand on our previous work by ...