Powered by OpenAIRE graph
Found an issue? Give us feedback
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao https://doi.org/10.1...arrow_drop_down
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao
DBLP
Conference object
Data sources: DBLP
versions View all 2 versions
addClaim

DDO-Free XQuery

Authors: Hiroyuki Kato; Yasunori Ishihara; Torsten Grust;

DDO-Free XQuery

Abstract

XQuery has an order-sensitive semantics in the sense that it requires nodes to be sorted in document order without duplicates (or in Distinct Document Order, DDO for short). This paper shows that for a given XQuery expression and a nested-relational DTD, the input expression can be transformed into an expression that can be evaluated without---potentially costly---ordering operations even if the input query requires its result to be in DDO. To this end, we propose an XQuery transformation algorithm that consists of simple rewriting rules. The basic idea is inspired by a generate-and-test approach as commonly used for solving search problems. We apply this approach when constructing the transformed expression: first, a skeleton query is prepared for the generate phase. This skeleton query can be evaluated without DDO, but it has the ability to return all nodes in DDO for all XML documents that conform to the input DTD. Second, an output expression is generated by injecting conditions for the test phase, which are extracted from the input expression, into the skeleton query. The key to performing both the extraction and injection of conditions in a systematic way is to utilize XQuery transformations that preserve equivalence up to DDO.

  • BIP!
    Impact byBIP!
    selected citations
    These citations are derived from selected sources.
    This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    0
    popularity
    This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
    Average
    influence
    This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
    Average
    impulse
    This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
    Average
Powered by OpenAIRE graph
Found an issue? Give us feedback
selected citations
These citations are derived from selected sources.
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
0
Average
Average
Average
Upload OA version
Are you the author of this publication? Upload your Open Access version to Zenodo!
It’s fast and easy, just two clicks!