The Research Of Fragment And Distribution Based On LCWA

A transaction consists of a serial of operations, and has ACID properties. However, in large-scale distributed applications, the traditional transaction model is not applicable. With a centralized database system developing, distributed database system has been developing, and it is the product of database technology and network technology. The fragment and distribution of data in the distributed database are very important. A relational database can be viewed as a directed graph constructed by tuples and foreign key references.A transaction model based on Local Closed World Assumption, the model divide the data in the local into the controlled data and the referenced data, as well as data replication, is proposed. Its features, concurrency control and correctness are also investigated and demonstrated. This transaction model is illustrated with a teaching management system.This paper proposes a method of data extraction based on multi-root tree, instead of traditional horizontal fragment and vertical fragment of data. The method of data extraction proposed by this paper is different from data extraction at the present stage. To facilitate data replication and sharing, semantic-relativity and logically independence should be satisfied when relational data is extracted. Multi-tree structures are employed as clusters of such data extracted from a relational database in this paper. Then the corresponding data extraction approach is proposed and implemented. We evaluate the extraction algorithm on a TPC-C database in Oracle, demonstrating the effectiveness and generalization of the approach. After the data extraction, the data must be assigned to sites suitably. This paper introduces a method of benefit and estimation for assigning data.Finally, the paper introduces the frame of a cloud Platform and set up it with the open source tools.