Schemas for Integration and Translation of Structured and Semi-structured Data
ICDT '99 Proceedings of the 7th International Conference on Database Theory
The complexity of relational query languages (Extended Abstract)
STOC '82 Proceedings of the fourteenth annual ACM symposium on Theory of computing
Keyword Searching and Browsing in Databases using BANKS
ICDE '02 Proceedings of the 18th International Conference on Data Engineering
Interconnection semantics for keyword search in XML
Proceedings of the 14th ACM international conference on Information and knowledge management
Parameterized Complexity Theory (Texts in Theoretical Computer Science. An EATCS Series)
Parameterized Complexity Theory (Texts in Theoretical Computer Science. An EATCS Series)
Finding and approximating top-k answers in keyword proximity search
Proceedings of the twenty-fifth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Discover: keyword search in relational databases
VLDB '02 Proceedings of the 28th international conference on Very Large Data Bases
VLDB '04 Proceedings of the Thirtieth international conference on Very large data bases - Volume 30
Keyword proximity search in complex data graphs
Proceedings of the 2008 ACM SIGMOD international conference on Management of data
Learning to create data-integrating queries
Proceedings of the VLDB Endowment
SPARK: A Keyword Search Engine on Relational Databases
ICDE '08 Proceedings of the 2008 IEEE 24th International Conference on Data Engineering
Keyword search in databases: the power of RDBMS
Proceedings of the 2009 ACM SIGMOD International Conference on Management of data
ExQueX: exploring and querying XML documents
Proceedings of the 2009 ACM SIGMOD International Conference on Management of data
Keyword search over relational tables and streams
ACM Transactions on Database Systems (TODS)
From keywords to semantic queries-Incremental query construction on the semantic web
Web Semantics: Science, Services and Agents on the World Wide Web
Journal of Computer and System Sciences
Exploratory keyword search on data graphs
Proceedings of the 2010 ACM SIGMOD International Conference on Management of data
A personal perspective on keyword search over data graphs
Proceedings of the 16th International Conference on Database Theory
Extracting minimum-weight tree patterns from a schema with neighborhood constraints
Proceedings of the 16th International Conference on Database Theory
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Tools that automatically generate queries are useful when schemas are hard to understand due to size or complexity. Usually, these tools find minimal tree patterns that contain a given set (or bag) of labels. The labels could be, for example, XML tags or relation names. The only restriction is that, in a tree pattern, adjacent labels must be among some specified pairs. A more expressive framework is developed here, where a schema is a mapping of each label to a collection of bags of labels. A tree pattern conforms to the schema if for all nodes v, the bag comprising the labels of the neighbors is contained in one of the bags to which the label of v is mapped. The problem at hand is to find a minimal tree pattern that conforms to the schema and contains a given bag of labels. This problem is NP-hard even when using the simplest conceivable language for describing schemas. In practice, however, the set of labels is small, so efficiency is realized by means of an algorithm that is fixed-parameter tractable (FPT). Two languages for specifying schemas are discussed. In the first, one expresses pairwise mutual exclusions between labels. Though W[1]-hardness (hence, unlikeliness of an FPT algorithm) is shown, an FPT algorithm is described for the case where the mutual exclusions form a circular-arc graph (e.g., disjoint cliques). The second language is that of regular expressions, and for that another FPT algorithm is described.