Recently, attention has been focused on spatial query language which is used to query spatial databases. A design of spatial query language has been presented in this paper by extending the standard relational databas...Recently, attention has been focused on spatial query language which is used to query spatial databases. A design of spatial query language has been presented in this paper by extending the standard relational database query language SQL. It recognizes the significantly different requirements of spatial data handling and overcomes the inherent problems of the application of conventional database query languages. This design is based on an extended spatial data model, including the spatial data types and the spatial operators on them. The processing and optimization of spatial queries have also been discussed in this design. In the end, an implementation of this design is given in a spatial query subsystem.展开更多
In this paper, an interval-gap-based 1NF temporal tuple calculus language and the corresponding temporal relation algebra are established on the basis of considering the trouble of stack operations in both S. Gadia’s...In this paper, an interval-gap-based 1NF temporal tuple calculus language and the corresponding temporal relation algebra are established on the basis of considering the trouble of stack operations in both S. Gadia’s TCAL and temporal tuple calculus due to their NINF.展开更多
Text2SQL技术通过减少非专业用户与关系数据库交互的技术障碍,已发展为数据分析和数据库管理的重要工具.以GPT为代表的大语言模型(large language model,LLM)的引入,进一步提升了Text2SQL系统的性能.然而,由于空间数据涉及复杂的几何关...Text2SQL技术通过减少非专业用户与关系数据库交互的技术障碍,已发展为数据分析和数据库管理的重要工具.以GPT为代表的大语言模型(large language model,LLM)的引入,进一步提升了Text2SQL系统的性能.然而,由于空间数据涉及复杂的几何关系、多样化的查询类型和对高精度语义理解的需求,现有的Text2SQL技术难以直接适用于空间数据库领域.为了解决上述问题,降低普通用户与空间数据库的交互门槛,提出了面向空间数据库的自然语言查询(natural language query,NLQ)转换方法.该方法有两个核心阶段:(1)自然语言理解;(2)可执行语言生成.在阶段(1)中使用实体信息提取算法提取关键查询实体,并基于大语言模型构建空间数据查询语料库进而确定查询类型.在阶段(2)中根据查询类型选择结构化语言模型(structured language model,SLM),然后将实体映射到结构化语言模型中,得到最终的空间数据库可执行语言.在多组真实数据集上的实验结果表明,该方法可以实现从用户的自然语言查询到空间数据库可执行语言的高效转换.展开更多
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,al...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.展开更多
基金This work is supported by the National High Technology Research and Development Program ofChina(2 0 0 2 AA135 2 30 ) and the Major Project of National Natural Science Foundation of Beijing(4 0 110 0 2 ) .
文摘Recently, attention has been focused on spatial query language which is used to query spatial databases. A design of spatial query language has been presented in this paper by extending the standard relational database query language SQL. It recognizes the significantly different requirements of spatial data handling and overcomes the inherent problems of the application of conventional database query languages. This design is based on an extended spatial data model, including the spatial data types and the spatial operators on them. The processing and optimization of spatial queries have also been discussed in this design. In the end, an implementation of this design is given in a spatial query subsystem.
基金Supported by both the High Technology Research Development Programme of Chinathe National Natural Science Foundation of China
文摘In this paper, an interval-gap-based 1NF temporal tuple calculus language and the corresponding temporal relation algebra are established on the basis of considering the trouble of stack operations in both S. Gadia’s TCAL and temporal tuple calculus due to their NINF.
文摘Text2SQL技术通过减少非专业用户与关系数据库交互的技术障碍,已发展为数据分析和数据库管理的重要工具.以GPT为代表的大语言模型(large language model,LLM)的引入,进一步提升了Text2SQL系统的性能.然而,由于空间数据涉及复杂的几何关系、多样化的查询类型和对高精度语义理解的需求,现有的Text2SQL技术难以直接适用于空间数据库领域.为了解决上述问题,降低普通用户与空间数据库的交互门槛,提出了面向空间数据库的自然语言查询(natural language query,NLQ)转换方法.该方法有两个核心阶段:(1)自然语言理解;(2)可执行语言生成.在阶段(1)中使用实体信息提取算法提取关键查询实体,并基于大语言模型构建空间数据查询语料库进而确定查询类型.在阶段(2)中根据查询类型选择结构化语言模型(structured language model,SLM),然后将实体映射到结构化语言模型中,得到最终的空间数据库可执行语言.在多组真实数据集上的实验结果表明,该方法可以实现从用户的自然语言查询到空间数据库可执行语言的高效转换.
基金Weaponry Equipment Pre-Research Foundation of PLA Equipment Ministry (No. 9140A06050409JB8102)Pre-Research Foundation of PLA University of Science and Technology (No. 2009JSJ11)
文摘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.
