Query containment for data integration systems

Query evaluation techniques for data integration systems

Dynamic Query Scheduling in Data Integration Systems

Execution plans produced by traditional query optimizers for data integration queries may yield poor performance for several reasons. The cost estimates may be inaccurate, the memory available at run-time may be insufficient, or data delivery rate can be unpredictable. In this paper, we address the problem of unpredictable data arrival rate. We propose to dynamically schedule queries in order t...

View-Based Query Answering and Query Containment over Semistructured Data

The basic querying mechanism over semistructured data, namely regular path queries, asks for all pairs of objects that are connected by a path conforming to a regular expression. We consider conjunctive two-way regular path queries (C2RPQ ’s), which extend regular path queries with two features. First, they add the inverse operator, which allows for expressing navigations in the database that t...

A Dynamic Query Processing Architecture for Data Integration Systems

Execution plans produced by traditional query optimizers for data integration queries may yield poor performance for several reasons. The cost estimates may be inaccurate, the memory available at run-time may be insufficient, or the data delivery rate can be unpredictable. All these problems have led database researchers and implementors to resort to dynamic strategies to correct or adapt the s...

Query rewriting for open XML data integration systems

This paper presents OpenXView, a model for open XML data integration systems, characterized by the autonomy of users that publish XML data on a common topic. Autonomy implies frequent and unpredictable changes to data and a high degree of structure heterogeneity. The OpenXView model provides an original integration schema, based on a hybrid ontology XML schema structure. We propose solutions fo...