Function of each layer of data warehouse

1.ods

Record source data , It is conducive to the source problem tracking

2.dim layer

Dimension surface , Integrate dimensions

3.1dwd layer

Wide surface , Integrate multiple dimensions of a topic into a table , For the later multi-dimensional analysis

3.2dws layer

Summarize data according to different dimensions

Not responsible for historical data in the same period

4 app layer

Data provided for business use

Keep historical statistics

Be responsible for historical data of the same period