Research On Temporal Data Modeling And Query Processing Based On JSON

As a ubiquitous form of data in human natural life,time has been widely used in military,finance,medical treatment,environment and other fields.Therefore,temporal data models used to express the dynamic development process of data objects have been proposed constantly.Currently,the main research achievements focus on temporal database and temporal XML.With the rapid development and popularization of network technology,the requirement of efficiency and security is getting higher and higher.JSON,a new generation of data exchange language,has been widely used because of its lightweight,fast parsing and high transmission efficiency.However,temporal modeling temporal information with JSON has not been studied enough.This thesis proposes a temporal data model based on JSON,and extends the traditional JSON query language to obtain the temporal JSON query language.The specific research work is as follows:(1)Based on the non-temporal JSON tree model,a temporal JSON tree model with past,present and even future state information of data objects is proposed by adding valid time attribute information to the model,and the formal definition and implementation method of the temporal JSON tree model are given.At the same time,in the process of changing the content and structure of JSON documents with time,JSON Schema may lose the function of checking JSON documents,resulting in the inconsistency of JSON Schema and JSON documents in time.Based on the temporal JSON tree model,this thesis proposes a solution of JSON Schema consistency.In addition,the effectiveness and superiority of the temporal JSON model are illustrated by the application of case data,aiming at the method of managing document versions by the non-temporal JSON model and the temporal JSON model.(2)Because of the particularity of the temporal data in the model,the traditional JSON query language can not handle the temporal data well.Therefore,in order to manage the historical data of the model conveniently and efficiently,this thesis proposes a temporal JSON query language.Firstly,based on the traditional JSON query language JSONPath,the temporal JSONPath query language is obtained by putting forward temporal filter assertions.Then,based on the traditional JSON query language JSONiq,the temporal JSONiq query language is obtained by putting forward the logical relation keywords of time interval and computing expansion functions.Finally,the update operation of temporal JSONiq to temporal JSON documents is improved by putting forward a custom update function.(3)Design and implement a prototype system supporting temporal JSON query language,and demonstrate the validity of the research work in this thesis.In addition,the superiority of temporal JSON model over non-temporal JSON model in document version management is demonstrated by more perfect data sets.