Research On Concurrency Control Mechanism Of Materialized Views Consistency Maintenance In Data Warehouse

The concept of Data Warehouse emerged in 90' s last century. Data Warehouse develops quickly as a new research field. Data Warehouse is a huge complex system. How to manage data in Data Warehouse properly is a hard task. The technology of Materialized Views maintenance is an important branch of this task.Nearly all researches on this problem are focusing on the conflicts caused by data update of data source till now. This paper takes into consideration of almost all the possible changes of data sources deploying three-tier framework based on DB-ODS-DW to design and construct Data warehouse. This paper also discusses the problem of materialized views maintenance under this three-tier framework.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. At the point of DW/ODS interface this paper maintenances views in DW in an incremental way.