Minimization of XML Tree Pattern Queries in the Presence of Integrity Constraints

In this paper, we provide a polynomial-time tree pattern query minimization algorithm whose efficiency stems from two key observations: (i) Inherent redundant “components” usually exist inside the rudimentary query provided by the user. (ii) Irredundant nodes may become redundant when constraints such as co-occurrence and required child/descendant are given. We show the result that the algorithm obtained by first augmenting the input tree pattern using the constraints, and then applying minimization, always finds the unique minimal equivalent to the original query. We complement our analytical results with an experimental study that shows the effectiveness of our tree pattern minimization techniques.

[1]  Diego Calvanese,et al.  Dwq : Esprit Long Term Research Project, No 22469 on the Decidability of Query Containment under Constraints on the Decidability of Query Containment under Constraints , 2022 .

[2]  Wenfei Fan,et al.  Integrity constraints for XML , 2000, PODS.

[3]  Jignesh M. Patel,et al.  Structural joins: a primitive for efficient XML query pattern matching , 2002, Proceedings 18th International Conference on Data Engineering.

[4]  Peter T. Wood,et al.  Rewriting XQL Queries on XML Repositories , 2000, BNCOD.

[5]  Laks V. S. Lakshmanan,et al.  Minimization of tree pattern queries , 2001, SIGMOD '01.

[6]  Peter T. Wood.  Minimising Simple XPath Expressions , 2001, WebDB.

[7]  Dan Suciu,et al.  Containment and equivalence for an XPath fragment , 2002, PODS.

[8]  John Grant,et al.  Foundations of Semantic Query Optimization for Deductive Databases , 1988, Foundations of Deductive Databases and Logic Programming..

[9]  Alin Deutsch,et al.  A Query Language for XML , 1999, Comput. Networks.

[10]  Yangjun Chen,et al.  Efficient Processing of XML Tree Pattern Queries , 2006, J. Adv. Comput. Intell. Intell. Informatics.

[11]  Peter T. Wood,et al.  Containment for XPath Fragments under DTD Constraints , 2003, ICDT.

[12]  Karl Aberer,et al.  Query optimization in XML structured-document databases , 2005, The VLDB Journal.

[13]  Cong Yu,et al.  Constraint-based XML query rewriting for data integration , 2004, SIGMOD '04.

[14]  Yangjun Chen,et al.  On the Graph Traversal and Linear Binary-Chain Programs , 2003, IEEE Trans. Knowl. Data Eng..

[15]  Peter T. Wood,et al.  Optimising Web queries using document type definitions , 1999, WIDM '99.

[16]  Scott Boag,et al.  XQuery 1.0 : An XML Query Language , 2007 .

[17]  Peter T. Wood,et al.  On the Equivalence of XML Patterns , 2000, Computational Logic.

[18]  Jennifer Widom,et al.  Query Optimization for XML , 1999, VLDB.

[19]  Dan Suciu,et al.  Query containment for conjunctive queries with regular expressions , 1998, PODS.

[20]  David S. Johnson,et al.  Computers and Intractability: A Guide to the Theory of NP-Completeness , 1978 .

[21]  Yangjun Chen,et al.  On the Signature Tree Construction and Analysis , 2006, IEEE Transactions on Knowledge and Data Engineering.

[22]  Dongwon Lee,et al.  Constraints-Preserving Transformation from XML Document Type Definition to Relational Schema , 2000, ER.