Multiple Materialized View Selection for XPath Query Rewriting

We study the problem of answering XPATH queries using multiple materialized views. Despite the efforts on answering queries using single materialized view, answering queries using multiple views remains relatively new. We address two important aspects of this problem: multiple-view selection and equ...

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Bibliographic Details
Published in2008 IEEE 24th International Conference on Data Engineering pp. 873 - 882
Main Authors Nan Tang, Yu, J.X., Ozsu, M.T., Byron Choi, Kam-Fai Wong
Format Conference Proceeding
LanguageEnglish
Published IEEE 01.04.2008
Subjects
Costs
Encoding
Filters
Internet
Query processing
Refining
Relational databases
Research and development
XML
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Summary:We study the problem of answering XPATH queries using multiple materialized views. Despite the efforts on answering queries using single materialized view, answering queries using multiple views remains relatively new. We address two important aspects of this problem: multiple-view selection and equivalent multiple-view rewriting. With regards to the first problem, we propose an NFA-based approach (called VFILTER) to filter views that cannot be used to answer a given query. We then present the criterion for multiple view/query answerability. Based on the output of VFILTER, we further propose a heuristic method to identify a minimal view set that can answer a given query. For the problem of multiple-view rewriting, we first refine the materialized fragments of each selected view (like pushing selection), we then join the refined fragments utilizing an encoding scheme. Finally, we extract the result of the query from the materialized fragments of a single view. Experiments show the efficiency of our approach.
ISBN:9781424418367
1424418364
ISSN:1063-6382
2375-026X
DOI:10.1109/ICDE.2008.4497496