Minimization of tree pattern queries
SIGMOD '01 Proceedings of the 2001 ACM SIGMOD international conference on Management of data
Containment and equivalence for an XPath fragment
Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Covering indexes for branching path queries
Proceedings of the 2002 ACM SIGMOD international conference on Management of data
Efficient algorithms for minimizing tree pattern queries
Proceedings of the 2002 ACM SIGMOD international conference on Management of data
Statistical synopses for graph-structured XML databases
Proceedings of the 2002 ACM SIGMOD international conference on Management of data
EDBT '02 Proceedings of the 8th International Conference on Extending Database Technology: Advances in Database Technology
Containment for XPath Fragments under DTD Constraints
ICDT '03 Proceedings of the 9th International Conference on Database Theory
DataGuides: Enabling Query Formulation and Optimization in Semistructured Databases
VLDB '97 Proceedings of the 23rd International Conference on Very Large Data Bases
Views in a Large Scale XML Repository
Proceedings of the 27th International Conference on Very Large Data Bases
XPath Containment in the Presence of Disjunction, DTDs, and Variables
ICDT '03 Proceedings of the 9th International Conference on Database Theory
Exploiting Local Similarity for Indexing Paths in Graph-Structured Data
ICDE '02 Proceedings of the 18th International Conference on Data Engineering
XQuery containment in presence of variable binding dependencies
WWW '05 Proceedings of the 14th international conference on World Wide Web
Benefits of path summaries in an XML query optimizer supporting multiple access methods
VLDB '05 Proceedings of the 31st international conference on Very large data bases
Semantic querying of tree-structured data sources using partially specified tree patterns
Proceedings of the 14th ACM international conference on Information and knowledge management
Containment of Partially Specified Tree-Pattern Queries
SSDBM '06 Proceedings of the 18th International Conference on Scientific and Statistical Database Management
XSEarch: a semantic search engine for XML
VLDB '03 Proceedings of the 29th international conference on Very large data bases - Volume 29
VLDB '04 Proceedings of the Thirtieth international conference on Very large data bases - Volume 30
On testing satisfiability of tree pattern queries
VLDB '04 Proceedings of the Thirtieth international conference on Very large data bases - Volume 30
Containment of nested XML queries
VLDB '04 Proceedings of the Thirtieth international conference on Very large data bases - Volume 30
Evaluation of partial path queries on xml data
Proceedings of the sixteenth ACM conference on Conference on information and knowledge management
Efficient evaluation of generalized path pattern queries on XML data
Proceedings of the 17th international conference on World Wide Web
A heuristic approach for checking containment of generalized tree-pattern queries
Proceedings of the 17th ACM conference on Information and knowledge management
Containment of partially specified tree-pattern queries in the presence of dimension graphs
The VLDB Journal — The International Journal on Very Large Data Bases
An original semantics to keyword queries for XML using structural patterns
DASFAA'07 Proceedings of the 12th international conference on Database systems for advanced applications
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The wide adoption of XML has increased the interest of the database community on tree-structured data management techniques. Querying capabilities are provided through tree-pattern queries. The need for querying tree-structured data sources when their structure is not fully known, and the need to integrate multiple data sources with different tree structures have driven, recently, the suggestion of query languages that relax the complete specification of a tree pattern. In this paper, we use a query language which allows partial tree-pattern queries (PTPQs). The structure in a PTPQ can be flexibly specified fully, partially or not at all. To evaluate a PTPQ, we exploit index graphs which generate an equivalent set of "complete" tree-pattern queries.In order to process PTPQs, we need to efficiently solve the PTPQ satisfiability and containment problems. These problems become more complex in the context of PTPQs because the partial specification of the structure allows new, non-trivial, structural expressions to be derived from those explicitly specified in a PTPQ. We address the problem of PTPQ satisfiability and containment in the absence and in the presence of index graphs, and we provide necessary and sufficient conditions for each case. To cope with the high complexity of PTPQ containment in the presence of index graphs,we study a family of heuristic approaches for PTPQ containment based on structural information extracted from the index graph in advance and on-the-fly. We implement our approaches and we report on their extensive experimental evaluation and comparison.