My graduation thesis-second type of slow change dimension

Abstract Yes

With the development of computers and the increasing number of data islands in information systems, how to use the data is a problem facing every enterprise.ETLYesexponential Data Extraction(Extract), Data Conversion(Transform)And Data Loading(Loading)And plays a key role in the application of data warehouse.ETLUse these data islands to form a data warehouse,It is an extremely important part in building a data warehouse. Slow change dimension refersETLUpdate the dimension table of the data warehouse. The dimension update speed of the Data Warehouse is studied. dimension tables are divided into stable dimensions, gradient dimensions, and quick change dimensions. Updating a data warehouse does not simply overwrite historical data. In order to store historical data in a data warehouse, many data warehouse designers have proposed a variety of data warehouse update policies. In actual business applications, three types of slow change dimensions are most used: first, second, and third.

Need for slowly changing dimensionsETLProgramAnd data warehouse support. FromETLAndOLAP(Connection Analysis and Processing) to introduce the design process of the second type of slowly changing dimension. It involves the ing between dimension tables and data warehouse source tables, the differences and connections between proxy keys and business keys, and the update policies and steps between different attributes of columns that slowly change dimension, and the parent-child dimension to infer the impact of members on the slowly changing dimension. This article alsoETLThe process of updating the data warehouse in the second type of slow change dimension is analyzed in detail.,ImplementationAlgorithmAfter careful discussion. NET Framework 2.0Programming to Implement its processing process, and testing related applications. Finally, the problems faced by slow change dimensions in practical applications are summarized.

Keywords:ETL, OLAP,Dimension, slowly changing dimension
PS: for ETL, the introduction to OLAP is to extract other words.ArticleThanks to the original author.
Attachment: Research and Application of the second type of slow and variable dimensions in etl.rar