Research On Temporal RDF Model Index

Time information is widely used in various practical applications,many application fields use temporal information to describe effective data.With the rapid development of Web technologies and the emergence of massive Web data,the RDF(Resource Description Framework)model supporting Web data semantic representation and processing has been more and more widely used.The Web has significant dynamic characteristics.The classic RDF model can only represent the current state of the Web data,it can not track the historical process of the Web data and predict the future state of the data.In order to accurately represent and process RDF data on the Web,the researchers proposed a temporal RDF model.At present,the widespread use of RDF models in dynamic Web environments has led to the emergence of large-scale temporal RDF data.How to quickly obtain the required semantic information from massive temporal RDF data has become an important issue in the realization of temporal RDF data management.The temporal RDF model index is an effective way to solve this problem.To address the current lack of an effective indexing mechanism for temporal RDF models,this thesis is devoted to the research of indexing method of temporal RDF model.Based on the further study of the classical RDF indexing method and the temporal RDF model,two different temporal RDF indexing mechanisms are proposed based on the structure and semantic features of the temporal RDF model.On the one hand,they provide valid indexes for the temporal RDF model and provide a solution for efficient query.Meanwhile,they provide theoretical bases for the further study of temporal RDF index.The specific research work of this thesis is as follows:(1)According to the transaction time of the temporal data model and the triple representation of the RDF model,the triple representation of the temporal RDF model and the indexing mechanism for the temporal RDF triple are presented,and the data structure and construction algorithm of the index are given.Through the experiment,the performance of the index and the query efficiency supported by the index are evaluated.The application scenarios of the temporal RDF triple index and the suitable query types are summarized.(2)Aiming at the graph representation of valid time and temporal RDF model of temporal data model,the graph representation of temporal RDF model and the graph index mechanism of temporal RDF graph oriented to the characteristics of graph data structure are proposed,the data structure and construction algorithm of temporal RDF graph index are given,and the maintenance method of temporal RDF graph index is provided.For the index based on the temporal RDF triple and the index based on temporal RDF graph proposed in this thesis,the performance of the two indexes and the query efficiency supported by the indexes are compared experimentally,and the applicable application scenarios of the two indexes are summarized.