摘要：Data currency is a temporal reference of data, it reflects the degree to which the data is current with the worldit models. Currency rule is a formal rule extracted from the data set and reflecting the currency order of thedata tuples, it can be used for both data repairing and currency quality evaluation. Based on the research of datacurrency repairing, the basic form of currency rule is extended, and parallel rule extraction and update algorithmsare proposed to meet the requirement of running on dynamic data sets. Besides, four data currency qualityevaluation models are proposed and verified by experiments. The performance test show that the efficiencyof parallel algorithms is significantly improved, the rules compliance mean(CM2) model based on extendedcurrency rule has the highest average precision. The extended currency rules not only improve the efficiencyand adaptability, but also provide more valuable features for data quality evaluation.
