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» A study of query length
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DBPL
1995
Springer
106views Database» more  DBPL 1995»
15 years 10 months ago
On Impossibility of Decremental Recomputation of Recursive Queries in Relational Calculus and SQL
We study the problem of maintaining recursively-de ned views, such as the transitive closure of a relation, in traditional relational languages that do not have recursion mechanis...
Guozhu Dong, Leonid Libkin, Limsoon Wong
AAAI
2006
15 years 8 months ago
Characterizing Data Complexity for Conjunctive Query Answering in Expressive Description Logics
Description Logics (DLs) are the formal foundations of the standard web ontology languages OWL-DL and OWL-Lite. In the Semantic Web and other domains, ontologies are increasingly ...
Magdalena Ortiz, Diego Calvanese, Thomas Eiter
WWW
2008
ACM
15 years 6 months ago
Discovering co-located queries in geographic search logs
A geographic search request contains a query consisting of one or more keywords, and a search-location that the user searches for. In this paper, we study the problem of discoveri...
Xiangye Xiao, Longhao Wang, Xing Xie, Qiong Luo
WWW
2006
ACM
16 years 7 months ago
Retroactive answering of search queries
Major search engines currently use the history of a user's actions (e.g., queries, clicks) to personalize search results. In this paper, we present a new personalized service...
Beverly Yang, Glen Jeh
SIGMOD
2008
ACM
145views Database» more  SIGMOD 2008»
16 years 7 months ago
Optimizing complex queries with multiple relation instances
Today's query processing engines do not take advantage of the multiple occurrences of a relation in a query to improve performance. Instead, each instance is treated as a dis...
Yu Cao, Gopal C. Das, Chee Yong Chan, Kian-Lee Tan