Access path selection in a relational database management system
SIGMOD '79 Proceedings of the 1979 ACM SIGMOD international conference on Management of data
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VLDB '97 Proceedings of the 23rd International Conference on Very Large Data Bases
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Proceedings of the 27th International Conference on Very Large Data Bases
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VLDB '05 Proceedings of the 31st international conference on Very large data bases
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ICDE '06 Proceedings of the 22nd International Conference on Data Engineering
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Proceedings of the 2006 ACM SIGMOD international conference on Management of data
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IBM Systems Journal
XSKETCH synopses for XML data graphs
ACM Transactions on Database Systems (TODS)
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VLDB '02 Proceedings of the 28th international conference on Very Large Data Bases
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
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DEXA '08 Proceedings of the 19th international conference on Database and Expert Systems Applications
DASFAA '09 Proceedings of the 14th International Conference on Database Systems for Advanced Applications
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Proceedings of the 13th International Conference on Extending Database Technology
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Proceedings of the 19th international conference on World wide web
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International Journal of Web Engineering and Technology
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Proceedings of the Fourteenth International Database Engineering & Applications Symposium
Efficiency frontiers of XML cardinality constraints
Data & Knowledge Engineering
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Though inevitable for effective cost-based query rewriting, the derivation of meaningful cardinality estimates has remained a notoriously hard problem in the context of XQuery. By basing the estimation on a relational representation of the XQuery syntax, we show how existing cardinality estimation techniques for XPath and proven relational estimation machinery can play together to yield dependable forecasts for arbitrary XQuery (sub)expressions. Our approach benefits from a light-weight form of data flow analysis. Abstract domain identifiers guide our query analyzer through the estimation process and allow for informed decisions even in case of deeply nested XQuery expressions. A variant of projection paths [15] provides a versatile interface into which existing techniques for XPath cardinality estimation can be plugged in seamlessly. We demonstrate an implementation of this interface based on data guides. Experiments show how our approach can equally cope with both, structure-and value-based queries. It is robust with respect to intermediate estimation errors, from which we typically found our implementation to recover gracefully.