This paper decomposes materialized views maintenance into ods / db interface and dw / ods interface . multiple data sources with concurrent updates may result in update anomalies of the materialized views . so at ods / db interface this paper introduces an improved nested transaction model - based transaction concurrency control mechanism to maintenance views in ods on line 本文把视图的一致性维护问题分解到三层结构的ods / dw和dw / ods两个接口上分别实现，并且引入视图生成树的概念，在ods / db接口处采用基于改进嵌套事务模型的并发控制机制，联机维护ods的数据，大大提高了视图维护过程中的并发度和灵活性。
