Navigation-driven evaluation of virtual mediated views

Bertram Ludäscher, Yannis Papakonstantinou, Pavel Velikhov

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The MIX mediator systems incorporates a novel framework for navigation-driven evaluation of virtual mediated views. Its architecture allows the on-demand computation of views and query results as the user navigates them. The evaluation scheme minimizes superfluous source access through the use of lazy mediators that translate incoming client navigations on virtual XML views into navigations on lower level mediators or wrapped sources. The proposed demand-driven approach is inevitable for handling up-to-date mediated views of large Web sources or query results. The non-materialization of the query answer is transparent to the client application since clients can navigate the query answer using a subset of the standard DOM API for XML documents. We elaborate on query evaluation in such a framework and show how algebraic plans can be implemented as trees of lazy mediators. Finally, we present a new buffering technique that can mediate between the ne granularity of DOM navigations and the coarse granularity of real world sources. This drastically reduces communication overhead and also simplifies wrapper development. An implementation of the system is available on the Web.

Original languageEnglish (US)
Title of host publicationAdvances in Database Technology - EDBT 2000 - 7th International Conference on Extending Database Technology, Proceedings
EditorsCarlo Zaniolo, Peter C. Lockemann, Marc H. Scholl, Torsten Grust
Number of pages16
ISBN (Electronic)3540672273, 9783540672272
StatePublished - 2000
Externally publishedYes
Event7th International Conference on Extending Database Technology, EDBT 2000 - Konstanz, Germany
Duration: Mar 27 2000Mar 31 2000

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other7th International Conference on Extending Database Technology, EDBT 2000

ASJC Scopus subject areas

  • Theoretical Computer Science
  • General Computer Science


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