Dynamic conjunctive queries
Dynamic conjunctive queries
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动态连接查询
DOI:
10.1016/j.jcss.2017.03.014
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发表时间:
2017
期刊:
影响因子:
--
通讯作者:
Thomas Schwentick
中科院分区:
文献类型:
--
作者:
Thomas Zeume;Thomas Schwentick
The article investigates classes of queries maintainable by conjunctive queries and their extensions and restrictions in the dynamic complexity framework of Patnaik and Immerman. Starting from the basic language of quantifier-free conjunctions of positive atoms, it studies the impact of additional operators and features — such as union, atomic negation and quantification — on the dynamic expressiveness, for the standard semantics as well as for Δ-semantics. The article identifies a linear hierarchy of five main fragments for the standard semantics, characterized by the addition of (1) arbitrary quantification and atomic negation, (2) existential quantification and atomic negation, (3) existential quantification, (4) atomic negation (but no quantification), and by (5) no addition to the basic language at all. While fragments (3), (4) and (5) can be separated, it remains open whether fragments (1), (2) and (3) are actually different. The fragments arising from Δ-semantics are also subsumed by the standard fragments (1), (2) and (4). Other fragments ofDynFOalso fit into this linear hierarchy.
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DOI:
10.1145/1807085.1807100
发表时间:
2010
期刊:
Proceedings of the twenty-ninth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
影响因子:
--
作者:
Christoph E. Koch
通讯作者:
Christoph E. Koch
影响因子:
0.5
作者:
Gelade, Wouter;Marquardt, Marcel;Schwentick, Thomas
通讯作者:
Schwentick, Thomas
影响因子:
1.2
作者:
Guozhu Dong;Jianwen Su
通讯作者:
Jianwen Su
DOI:
--
发表时间:
1995
期刊:
International Workshop/Symposium on Database Programming Languages
影响因子:
--
作者:
Guozhu Dong;L. Libkin;L. Wong
通讯作者:
L. Wong
影响因子:
1
作者:
T. Zeume;T. Schwentick
通讯作者:
T. Schwentick