Current skyline evaluation techniques assume a fixed ordering on the attributes. However, dynamic preferences on nominal attributes are more realistic in known applications. In order to generate online response for any such preference issued by a user, one obvious solution is to enumerate all possible preferences and materialize all results of these preferences. However, the pre-processing and ...

View materialization is an important technique for data warehousing, high performance query processing, and OLAP. Materialized views (MVs) are derived from base extents that may not be local. Queries can be answered using MVs more quickly than using the base extents. However, MVs may be affected by updates to the base extents. MVs can either be re-computed or incrementally updated to reflect th...

s – Data warehouse contains vast amount of data to support complex queries of various Decision Support Systems(DSSs). It needs to store materialized views of data, which must be available consistently and instantaneously. Using a frame metadata model, this paper presents an architecture of a universal data warehousing with different data models. The frame metadata model represents the metadata ...

Mythical and religious belief systems in a social context can be regarded as a conglomeration of sacrosanct rites which revolve around substantive values that involve an element of faith. Moreover, we can conclude that ideologies, myths and beliefs can all be analyzed in terms of systems within a cultural context. The significance of being able to define ideologies, myths and beliefs as systems...

ion Refinement for Ontology Materialization Birte Glimm, Yevgeny Kazakov, Thorsten Liebig, Trung-Kien Tran, and Vincent Vialard 1 University of Ulm, Ulm, Germany, [email protected] 2 derivo GmbH, Ulm, Germany, @derivo.de Abstract. We present a new procedure for ontology materialization (computing all entailed instances of every atomic concept) in which reasoning over...

We propose a framework for navigation-driven evaluation of virtual mediated views. The approach is based on lazy mediators that translate incoming client navigations on a virtual XML view (or the result of an XML query) into navigations on wrapped sources or lower level mediators. Such a demand-driven approach is inevitable in order to handle up-to-date mediated views of huge Web sources or lar...

As far as we know, in the open scientific literature, there is no generalized framework for the optimization of relational data warehouses which includes view and index selection and vertical view fragmentation. In this paper we are offering such a framework. We propose a formalized multidimensional model, based on relational schemas, which provides complete vertical view fragmentation and pres...

Data-warehousing applications cope with enormous data sets in the range of Gigabytes and Terabytes. Queries usually either select a very small set of this data or perform aggregations on a fairly large data set. Materialized views storing pre-computed aggregates are used to efficiently process queries with aggregations. This approach increases resource requirements in disk space and slows down ...

The federated view selection problem (FVSP) is an optimization technique designed to enhance query performance in a federated data warehouse environment through the materialization of select views given resource constraints and storage restrictions. Current research focuses on single-instance heuristics, which have difficulty scaling. In this work, we introduce two commonly used cooperative heu...