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Filtering unsatisfiable XPath queries

Jinghua Groppe, Sven Groppe
2008 Data & Knowledge Engineering  
of unsatisfiable queries.  ...  If an XPath query does not conform to the constraints given in the schema, the evaluation of the query will return an empty result for any valid XML document. Thus, the XPath query is unsatisfiable.  ...  [12] filters the unsatisfiable XPath queries by a set of simplification rules.  ... 
doi:10.1016/j.datak.2007.06.018 fatcat:fcsp5k4ajvek3eles4oe5wlete

FILTERING UNSATISFIABLE XPATH QUERIES
english

2006 Proceedings of the Eighth International Conference on Enterprise Information Systems   unpublished
of unsatisfiable queries.  ...  If an XPath query does not conform to the constraints given in the schema, the evaluation of the query will return an empty result for any valid XML document. Thus, the XPath query is unsatisfiable.  ...  [12] filters the unsatisfiable XPath queries by a set of simplification rules.  ... 
doi:10.5220/0002465001570162 fatcat:vulnov53pjg7fjdzxpcphqomla

Verification of Tree Updates for Optimization [chapter]

Michael Benedikt, Angela Bonifati, Sergio Flesca, Avinash Vyas
2005 Lecture Notes in Computer Science  
A recent example along this line are the update languages of [16, 15, 8] which add tree update primitives on top of the declarative query languages XPath and XQuery.  ...  These tree update languages use a "snapshot semantics", in which all querying is performed first, after which a generated sequence of concrete updates is performed in a fixed order determined by query  ...  Trees, Queries, and Tree Update Languages In this section, we review the basics of the data model and the fragment of the XPath query language considered in this work. Data Model.  ... 
doi:10.1007/11513988_37 fatcat:ojhdbawudrcgzekdibphwnfavq

Satisfiability algorithms for conjunctive queries over trees

James Cheney
2011 Proceedings of the 14th International Conference on Database Theory - ICDT '11  
We also analyze the complexity of important special cases: binary and k-ary intersection of certain classes of XPath expressions.  ...  Our main complexity result is that binary intersection (for positive, simple navigational XPath over all axes) is tractable for expressions with a bounded number of changes in direction in the path, which  ...  We show that satisfiability of k-ary intersections of forward positive XPath queries (involving child, descendant-or-self, and following-sibling steps and downward-only filters) is solvable in O(n k )  ... 
doi:10.1145/1938551.1938572 dblp:conf/icdt/Cheney11 fatcat:bv6lhu7tr5bmxgvhhpiiivhemi

Towards non-directional Xpath evaluation in a RDBMS

Sourav S. Bhowmick, Curtis Dyreson, Erwin Leonardi, Zhifeng Ng
2009 Proceeding of the 18th ACM conference on Information and knowledge management - CIKM '09  
translate XML queries to SQL.  ...  XML query languages use directional path expressions to locate data in an XML data collection.  ...  Consequently, some of the above XPath fragments may become unsatisfiable on the document in Figure 1 (b). Sally has to formulate a different set of XPath fragments to retrieve relevant information.  ... 
doi:10.1145/1645953.1646156 dblp:conf/cikm/BhowmickDLN09 fatcat:un2iybop7jggrdfo3qki3gjjzm

XPath Query Simplification with regard to the Elimination of Intersect and Except Operators

S. Groppe, S. Bottcher, J. Groppe
2006 22nd International Conference on Data Engineering Workshops (ICDEW'06)  
Furthermore, we show how to substitute the XPath 2.0 intersect and except operators in a given XPath query with computed filter expressions.  ...  XPath is widely used as an XML query language and is embedded in XQuery expressions and in XSLT stylesheets.  ...  Furthermore, our proposed rule set for XPath simplification can be used to check whether a query is unsatisfiable, i.e. the query result is equal to {} for every XML document.  ... 
doi:10.1109/icdew.2006.165 dblp:conf/icde/GroppeBG06 fatcat:4por6yplineqjnfgrce2bpzev4

The Query Translation Landscape: a Survey [article]

Mohamed Nadjib Mami, Damien Graux, Harsh Thakkar, Simon Scerri, Sören Auer, Jens Lehmann
2019 arXiv   pre-print
In particular, we study which query language is a most suitable candidate for that 'universal' query language.  ...  In this article, we survey more than forty query translation methods and tools for popular query languages, and classify them according to eight criteria.  ...  XPath/XQuery-to-SPARQL: [21] mentions support for recursive XPath queries, with descendent, following and preceding axes as well as for filters.  ... 
arXiv:1910.03118v1 fatcat:wsww5vhlwjhqjlouibetb6mo3a

XEvent: An Event Notification System over Distributed Hash Table (DHT) Networks

Ruili Wang, Weixiong Rao, Chengqi Zhang
2005 The IEEE intelligent informatics bulletin  
XEvent can support basic topic-based message subscription by use of XML schema as event topic, and further filter the whole message contents using XPath as the filtering language.  ...  ; (3) XEvent can filter and deliver event messages to subscribers with high efficiency by building a delivery tree based on the subscriber's XPath filters, and (4) XEvent can provide fault-tolerance for  ...  Using XPath as an XML query language can provide the filtering on both the structure and the contents of published XML information.  ... 
dblp:journals/cib/WangRZ05 fatcat:tnxblpdkwbbthemcaa7ojnvngi

Polynomial time fragments of XPath with variables

Emmanuel Filiot, Joachim Niehren, Jean-Marc Talbot, Sophie Tison
2007 Proceedings of the twenty-sixth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems - PODS '07  
We show that PPL remains FO-complete even though enjoying polynomial time query answering (and thus model checking).  ...  Variables in XPath 2.0 are fundamental for selecting n-tuples of nodes in trees.  ...  Since every recursive call to vals filters all unsatisfiable cases, every intermediate result can be extended to a whole solution.  ... 
doi:10.1145/1265530.1265559 dblp:conf/pods/FiliotNTT07 fatcat:iors7qp3rvhsrkszh2ggfh2jmu

Comparing XML path expressions

Pierre Genevès, Nabil Layaïda
2006 Proceedings of the 2006 ACM symposium on Document engineering - DocEng '06  
They notably include XPath comparisons such as equivalence (whether two queries always return the same result), and containment (whether for any tree the result of a particular query is included in the  ...  In the context of XSLT/XQuery analysis, query optimization, and XML type checking, XPath decision problems arise naturally.  ...  XPath queries are translated into the µ-calculus.  ... 
doi:10.1145/1166160.1166182 dblp:conf/doceng/GenevesL06 fatcat:dwsttxhcpvccxg2v6y44kxojga

Forward node-selecting queries over trees

Dan Olteanu
2007 ACM Transactions on Database Systems  
Node-selecting queries over trees lie at the core of several important XML languages for the Web, e.g., the node-selection language XPath, the query language XQuery and the transformation language XSLT  ...  The main question it answers positively is whether for each input query with forward and backward predicates there exists an equivalent forward-only output query.  ...  Note that XPath queries are LGQ forests, and XPath queries with identity-based equality are singlejoin DAGs [Olteanu 2004 ]. Example 2.4.  ... 
doi:10.1145/1206049.1206052 fatcat:qqruq5qqvzc5rdgbgn7ry5ahyu

Stream firewalling of xml constraints

Michael Benedikt, Alan Jeffrey, Ruy Ley-Wild
2008 Proceedings of the 2008 ACM SIGMOD international conference on Management of data - SIGMOD '08  
We isolate a class of DTDs and XPath constraints which support the generation of low-space filters, and provide algorithms for generating firewalls with low per-input-character time and per-stream space  ...  Note that these queries are all efficiently streamable, and that Q5 is fast-fail: once the first Protein_Name is returned, the query is unsatisfiable.  ...  In filtering one has a large collection of (user-supplied) XPath queries being executed on a single (system-supplied) streamed XML document -the goal of the middleware is to rapidly identify the elements  ... 
doi:10.1145/1376616.1376667 dblp:conf/sigmod/BenediktJL08 fatcat:uvhwc533bjgsvb3diaew7mlrbu

An Extensible Light-Weight XML-Based Monitoring System for Sequence Databases [chapter]

Dieter Van de Craen, Frank Neven, Kerstin Koch
2006 Lecture Notes in Computer Science  
To keep the system light-weight, we therefore introduce an optimization technique based on query containment to reduce the number of XPath-evaluations which constitutes the bottleneck of the system.  ...  In particular, it allows them to express their interest in certain data by means of queries/constraints; they are then notified when new data arrives satisfying these queries/constraints.  ...  Filtering systems such as XFilter, YFilter, XMLTK, . . . are freely available and provide efficient evaluation of large numbers of XPath-expressions.  ... 
doi:10.1007/11799511_25 fatcat:7yt4s5fo75a4xolsgrmcnkazva

Answering XPath Queries over Networks by Sending Minimal Views [chapter]

K TAJIMA, Y FUKUI
2004 Proceedings 2004 VLDB Conference  
When a client submits a set of XPath queries to a XML database on a network, the set of answer sets sent back by the database may include redundancy in two ways: some elements may appear in more than one  ...  In this paper, we propose a method of minimizing communication costs in XPath processing over networks.  ...  or unsatisfiable.  ... 
doi:10.1016/b978-012088469-8/50008-5 fatcat:misbah5hlnbhfgbkfkp64vyt7u

Answering XPath Queries over Networks by Sending Minimal Views [chapter]

Keishi Tajima, Yoshiki Fukui
2004 Proceedings 2004 VLDB Conference  
When a client submits a set of XPath queries to a XML database on a network, the set of answer sets sent back by the database may include redundancy in two ways: some elements may appear in more than one  ...  In this paper, we propose a method of minimizing communication costs in XPath processing over networks.  ...  or unsatisfiable.  ... 
doi:10.1016/b978-012088469-8.50008-5 dblp:conf/vldb/TajimaF04 fatcat:6uhxpguuazfj3pgj4joydjhvde
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