The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. ex. Some numerals are expressed as "XNUMX".
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The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. Copyrights notice
XQuery est devenu la norme pour interroger XML. Tout comme SQL, XQuery autorise les expressions imbriquées. Pour optimiser le traitement XQuery, de nombreuses recherches ont été effectuées sur la normalisation, c'est-à-dire la transformation d'expressions imbriquées en expressions équivalentes non imbriquées. Les règles de normalisation précédentes sont classées en deux catégories :niveau source/ et à la niveau algèbre/-selon qu'une construction est spécifiée dans la syntaxe XQuery ou sous forme d'expressions algébriques équivalentes. Du point de vue de l'implémentation, le premier est préférable au second car il peut être implémenté dans une variété de moteurs XQuery avec différentes algèbres. Cependant, les règles existantes au niveau source présentent plusieurs problèmes : elles ne gèrent pas les expressions quantifiées, entraînent des résultats de requête en double et utilisent de nombreux fichiers temporaires. Dans cet article, nous proposons de nouvelles règles de normalisation au niveau source qui résolvent ces problèmes. Grâce à des analyses et des expériences, nous montrons que nos règles de normalisation peuvent réduire le temps d'exécution des requêtes de quelques heures à quelques secondes et peuvent être adaptées à une variété de moteurs XQuery.
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Ki-Hoon LEE, Young-Ho PARK, "Revisiting Source-Level XQuery Normalization" in IEICE TRANSACTIONS on Information,
vol. E94-D, no. 3, pp. 622-631, March 2011, doi: 10.1587/transinf.E94.D.622.
Abstract: XQuery has become the standard for querying XML. Just like SQL, XQuery allows nested expressions. To optimize XQuery processing, a lot of research has been done on normalization, i.e., transforming nested expressions to equivalent unnested ones. Previous normalization rules are classified into two categories—source-level/ and algebra-level/—depending on whether a construct is specified in the XQuery syntax or as equivalent algebraic expressions. From an implementation point of view, the former is preferable to the latter since it can be implemented in a variety of XQuery engines with different algebras. However, existing source-level rules have several problems: They do not handle quantified expressions, incur duplicated query results, and use many temporary files. In this paper, we propose new source-level normalization rules that solve these problems. Through analysis and experiments, we show that our normalization rules can reduce query execution time from hours to a few seconds and can be adapted to a variety of XQuery engines.
URL: https://global.ieice.org/en_transactions/information/10.1587/transinf.E94.D.622/_p
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@ARTICLE{e94-d_3_622,
author={Ki-Hoon LEE, Young-Ho PARK, },
journal={IEICE TRANSACTIONS on Information},
title={Revisiting Source-Level XQuery Normalization},
year={2011},
volume={E94-D},
number={3},
pages={622-631},
abstract={XQuery has become the standard for querying XML. Just like SQL, XQuery allows nested expressions. To optimize XQuery processing, a lot of research has been done on normalization, i.e., transforming nested expressions to equivalent unnested ones. Previous normalization rules are classified into two categories—source-level/ and algebra-level/—depending on whether a construct is specified in the XQuery syntax or as equivalent algebraic expressions. From an implementation point of view, the former is preferable to the latter since it can be implemented in a variety of XQuery engines with different algebras. However, existing source-level rules have several problems: They do not handle quantified expressions, incur duplicated query results, and use many temporary files. In this paper, we propose new source-level normalization rules that solve these problems. Through analysis and experiments, we show that our normalization rules can reduce query execution time from hours to a few seconds and can be adapted to a variety of XQuery engines.},
keywords={},
doi={10.1587/transinf.E94.D.622},
ISSN={1745-1361},
month={March},}
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TY - JOUR
TI - Revisiting Source-Level XQuery Normalization
T2 - IEICE TRANSACTIONS on Information
SP - 622
EP - 631
AU - Ki-Hoon LEE
AU - Young-Ho PARK
PY - 2011
DO - 10.1587/transinf.E94.D.622
JO - IEICE TRANSACTIONS on Information
SN - 1745-1361
VL - E94-D
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JA - IEICE TRANSACTIONS on Information
Y1 - March 2011
AB - XQuery has become the standard for querying XML. Just like SQL, XQuery allows nested expressions. To optimize XQuery processing, a lot of research has been done on normalization, i.e., transforming nested expressions to equivalent unnested ones. Previous normalization rules are classified into two categories—source-level/ and algebra-level/—depending on whether a construct is specified in the XQuery syntax or as equivalent algebraic expressions. From an implementation point of view, the former is preferable to the latter since it can be implemented in a variety of XQuery engines with different algebras. However, existing source-level rules have several problems: They do not handle quantified expressions, incur duplicated query results, and use many temporary files. In this paper, we propose new source-level normalization rules that solve these problems. Through analysis and experiments, we show that our normalization rules can reduce query execution time from hours to a few seconds and can be adapted to a variety of XQuery engines.
ER -