The Research Of Multidimensional Data Modeling Based On ER

Data model is one of the key problems of DW. And many learns proved that traditional relation data model couldn't effectively describe the structure and semantic of DW applications, and couldn't meet the requirement of OLAP's applications also. Because the OLAP is multidimensional, the multidimensional data modeling techniques attract human's general attentions and wide interests.With the business competition becomes more and more hotly, the MISs couldn't completely meet the leader's requirements. They needed urgently a data warehouse system to help their decision-making. And how to build a data warehouse system based on MISs, how to build a multidimensional data model based on ER model attract human's general attentions.On these situations, this paper introduces the DW techniques,concludes the concept, motive, the present situation of researching,attentive problems of multidimensional data modeling and basic structures of multidimensional data model seriously,generalizes the present situation of conceptual modeling for multidimensional data based on ER model systemically, advocates a HPKM which can describe the multidimensional structure of DW well in detail.Based on the telecom industry,this paper describes the approach of conceptual multidimensional data modeling based on HPKM, and uses it to model the profit analysis subject, then compares it with the existing multidimensional data models. Based on the applications, this paper expatiates the approach of building the multidimensional data model based on the ER model. In the process of building the multidimensional data model, we made some mends on the time dimension, presents a time model based on inside competition, and this model provides enough information for the later analysis based on time. According to the project practice, this paper uses a new schema called star cluster schema as the basic structure of the multidimensional data model. The cluster schema is the joint of star schema and snowflake schema, it inherits their merits, and mends their disadvantages. This schema made good use in practice.