Correct understanding of four types of data warehouse modeling methods of SQL Server

SQL ServerCategory 4Data warehouse modelingMethods are mainly divided into the following four types.

The first type is the three-paradigm modeling of relational databases. We usually use the three-paradigm modeling method to build various types of operational database systems.

The second category is the three-paradigm data warehouse modeling promoted by inmon, which is different from the three-paradigm modeling of the operating database system in terms of focus.

Inmon's data warehouse modeling method is divided into three layers. The first layer is the entity relationship layer, that is, the business data model layer of the enterprise. At this layer, the modeling method of the enterprise's operational database system is the same as that of the enterprise.
The second layer is the data item set layer. The modeling method at this layer is different from the modeling method of the enterprise's operating database system based on factors such as the data generation frequency and Access frequency; layer 3 physical layer is Layer 2
Specific implementation.

Category 3 is the dimensional modeling of data warehouses promoted by Kimball. We generally call it star schema modeling, and sometimes add some snowflake models. Dimensional modeling is a user-oriented, easy-to-understand, and highly efficient modeling method. It is also my favorite modeling method.

The fourth type is a more flexible modeling method, which is usually used in the data preparation area of the background. The modeling method is eclectic to meet the needs. The created tables do not provide interfaces to users, mostly temporary tables.