Hypertree decompositions and tractable queries

@inproceedings{Gottlob1998HypertreeDA,
  title={Hypertree decompositions and tractable queries},
  author={Georg Gottlob and Nicola Leone and Francesco Scarcello},
  booktitle={ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems},
  year={1998}
}
1 A preliminary version of this paper appeared in the ‘‘Proceedings of the Eighteenth ACM Symposium on Principles of Database Systems (PODS’99),’’ pp. 21–32, Philadelphia, May 1999. Research supported by FWF (Austrian Science Funds) under the Project Z29-INF. Part of the work of Francesco Scarcello has been carried out while visiting the Technische Universitat Wien. Part of the work of Nicola Leone has been carried out while he was with the Technische Universitat Wien. Georg Gottlob 
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