Query Answering under Non-guarded Rules in Datalog+/-
Query Answering under Non-guarded Rules in Datalog+/-
复制标题
数据记录中非保护规则下的查询应答 /-
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
Andreas Pieris
中科院分区：
文献类型：
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作者：
A. Calí;G. Gottlob;Andreas Pieris
在基于本体的数据访问中，扩展数据库被本体增强，本体生成新的内涵知识，这些知识在回答查询时必须被考虑。在这种情况下，易处理的数据复杂性（即，复杂性w.r.t.考虑到需要处理大数据集，查询应答的数据（仅数据）是至关重要的。一个著名的易于处理的本体语言类是DL-lite家族;然而，在DL-lite中，不可能表达涉及连接的简单而有用的完整性约束。为了克服这一限制，可判定语言的Datasheet +/-类使用元组生成依赖（TGD）作为规则，从而允许规则体中的原子的连接，并有适当的限制以确保可判定性。特别是，TGD的粘性集允许在某些条件下在规则体中进行连接和变量重复。在本文中，我们通过引入TGD的弱粘性集来扩展粘性的概念，这也推广了著名的TGD的弱无环集。我们研究了这种语言下的查询回答的复杂性，此外，我们提供了新的复杂性结果的弱非循环集的TGD。此外，我们提出了一类新的粘性连接集的TGD，推广了粘性集的TGD和所谓的线性TGD，包含依赖的扩展。
In ontology-based data access, an extensional database is enhanced by an ontology that generates new intensional knowledge which has to be considered when answering queries. In this setting, tractable data complexity (i.e., complexity w.r.t. the data only) of query answering is crucial, given the need to deal with large data sets. A well-known class of tractable ontology languages is the DL-lite family; however, in DL-lite it is impossible to express simple and useful integrity constraints that involve joins. To overcome this limitation, the Datalog+/- class of decidable languages uses tuple-generating dependencies (TGDs) as rules, thus allowing for conjunctions of atoms in the rule bodies, with suitable limitations to ensure decidability. In particular, sticky sets of TGDs allow for joins and variable repetition in rule bodies under certain conditions. In this paper we extend the notion of stickiness by introducing weaklysticky sets of TGDs, which also generalize the well-known weakly-acyclic sets of TGDs. We investigate the complexity of query answering under such language, and in addition we provide novel complexity results on weakly-acyclic sets of TGDs. Moreover, we present the novel class of sticky-join sets of TGDs, which generalizes both sticky sets of TGDs and so-called linear TGDs, an extension of inclusion dependencies.
使用 F-logic Lite 及其扩展进行本体推理
DOI：
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发表时间：
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期刊：
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作者：
Andrea Cali (Co-Author)
通讯作者：
Andrea Cali (Co-Author)