Research And Application On Dynamic Modeling Technology Of The Semi-structured Data Management

As a result of the semi-structured data lack type information, so the storage and management of the data would be an important reaserch issue. In order to solve the difficult issue of the data storage and management, a dynamic modeling technology of the semi-structured data considring the feature of the structure irregular was proposed in this paper. Additionally, the treatment system for land approving in village-town was taken as an example to illustrate the effectiveness of this modeling technique.First, this paper proposed a conceptual model of the semi-structured data based on Object Exchange Model(OEM) which could solve the descriptive problem of the data with the irregular structure effectively. Then, found all the biggest simple path expression by carrying out the OEM depth-first traversal and then, added them to the dynamic tree in turn by adopting the ideas of hierarchical structure and the principle of cumulative count. The dynamic tree could not only be able to reflect the model information, to abstract the data structures easily, but also to update momentarily and flexibly considering the feature of the semi-structured data that the lack in data type information and the relax as well as the changing in descriptive structure, so as to overcome the storage uncertainty of the data. Therefore, this paper proposed the tree as the storage model of the semi-structured data(logical model). Finally, the semi-structured data storage and query in the relational databases would be achieved after mapping the dynamic tree storage model to the relationship table through a set of mapping rules proposed in this study. In this way, the query on the data would be transformed into the query on the relational table in the future. At the same time, the optimization ideas and the technology of the traditional relational query would be applied to the choice of a specific query execution plan. In addition, this study also discussed the incremental update algorithms of the semi-structured data tentatively. Another tree structure was introduced in the algorithm, which could record the information for the evaluation of the view on the database. With the help of this recorded information could reduce the amount of calculation and the data communications volume effectively when the data generated the incremental information and the database was updated.The dynamic modeling technology broke the traditional idea of the management of the semi-structured data, from the conceptual model of the semi-structured data to the storage model, and then achieved storage of semi-structured data, it could overcome the flexible characteristics of structure of semi-structured effectively at each stage, so it has a practical significance on the management of semi-structured data.