CAJ | 학술논문

为解决基于语义的关系数据集成中的查询处理正确性问题,形式化定义了SPARQL查询语句的语义.在查询重写过程中,发现查询相关的数据表并将其分解为最小可连接单元,再根据查询语义连接最小可连接单元来产生正确的查询.给出了基于语义的查询重写和查询转换算法.对算法复杂性进行了讨论,在最坏情况下,查询分解算法可在O(n2)时间内完成,查询重写的时间复杂度为O(nm).通过实验验证了算法的性能,实验结果表明当查询长度小于8,而数据源较多时,查询处理算法具有较好的效果.
위해결기우어의적관계수거집성중적사순처리정학성문제,형식화정의료SPARQL사순어구적어의.재사순중사과정중,발현사순상관적수거표병장기분해위최소가련접단원,재근거사순어의련접최소가련접단원래산생정학적사순.급출료기우어의적사순중사화사순전환산법.대산법복잡성진행료토론,재최배정황하,사순분해산법가재O(n2)시간내완성,사순중사적시간복잡도위O(nm).통과실험험증료산법적성능,실험결과표명당사순장도소우8,이수거원교다시,사순처리산법구유교호적효과.
To solve the query processing correctness problem for semantic-based relational data integration, the semantics of SAPRQL (simple protocol and RDF query language) queries is defined. In the course of query rewriting, all relative tables are found and decomposed into minimal connectable units. Minimal connectable units are joined according to semantic queries to produce the semantically correct query plans. Algorithms for query rewriting and transforming are presented. Computational complexity of the algorithms is discussed. Under the worst case,the query decomposing algorithm can be finished in O(n2) time and the query rewriting algorithm requires O(nm) time. And the performance of the algorithms is verified by experiments, and experimental results show that when the length of query is less than 8, the query processing algorithms can provide satisfactory performance.