Chinese Journal of Computers   Full Text
Title	Technology on Temporal XML Indexing
Authors	YE Xiao-Ping CHEN Kai-Yuan TANG Yong TANG NaHU Su
Address	(Department of Computer Science, Sun Yat-Sen University, Guangzhou 510275)
Year	2007
Issue	No.7(1074—1085)
Abstract &   Background	Abstract This paper is devoted to the technique and implementation of temporal XML indexing. Firstly, this paper proposes the schema of prefix-code based on the valid time of nodes, and introduces the temporal equivalence and temporal quasi-order relationships which result from the temporal connection and inclusion on the set of the valid time periods of all temporal nodes. Using these relationships, the paper builds the index model of temporal XML data, that is TXIDM, and the TXIDM has a characteristic of the re-nesting structure which may be more suitable to the random tree-type structure of the temporal XML data. Secondly, the paper discusses the index algorithm on temporal query (values query and path query) and temporal update (inserting and modification) and these two may be described uniformly as they are all based on the properties of the relationships especially the quasi-order. Finally, the paper completes the analysis of capability and the designing of the experimental simulation for the model and algorithm, and the experiment results suggest that the operation on temporal update and query are feasible and efficient. keywords prefix-code based on valid time; temporal XML index data model; temporal connected and included relationships; temporal query and update background This work was supported by the following research projects: The National Nature Science Foundation of China: "Research on Bi-Temporal XML Model and Applications" (No.60673135 )，"Research on Temporal Knowledge/Data Model and Software Components" (No.60373081)， and the Nature Science Foundation of Guangdong Province in China: "Study of Unified Model and Applied Software Component on Temporal Knowledge and Data" (No.04105503), "Study on Cooperated and Temporal Mechanism of Multi-Agent System and Exploitation of Software component" (No.5003348). These projects are mainly to be devoted to develop the new theories and techniques for the processing on the temporal data and knowledge information, such as an implementation on temporal query language, the temporal middle wares, temporal variables, the methods on bi-temporal index, the storing and query technology of temporal XML data, the approaches on temporal cooperation and so on. The authors have implemented the middleware TempDB V2.0 of temporal databases based on TSQL2 and the software component TempKB V1.0 ground on generation rules. The latter adopts the positive reasoning mechanism with temporal data which be driven by temporal demanding and supports the temporal driven constrain. These works are the fundamental of the paper. In addition, the authors have also completed the study on the semantics of temporal variables and proposed the processing techniques of temporal data based on these variables, and the manipulation approaches on bi-temporal data in the variable database. And then, the authors further extend these to the issues of temporal XML data. Of cause there are sharp differences between the temporal relation and the temporal XML, but both two may be enough to using the basic characteristic of the time periods of the corresponding data. The temporal relationships just are the key issue of the works described in the paper, for example, the paper builds the temporal index model by means of the temporal connection and inclusion relationships, and proposes the arithmetic of the query and update using the property of quasi-order. The further work of the authors is extending the TXIDM in order to implement the integrated semantics of the valid time variable, and study the binding of the variable within the operation of the temporal XML index.