Dimension table in DWH

 A Dimension table is a table in a star schema of the data warehouse. It stores attributes or dimensions that describe the object in a fact table.

Read here: About facttable

https://bageshkumarbagi-msbi.blogspot.com/2022/05/fact-tables-in-dwh.html

In other word we can say that a dimension table is a collection of reference information about a measurable event. These events are known as facts and stored in a fact table. Dimensions are very important in the data ware house. It has a primary key column that uniquely identifies each dimension record (row) and associated with a fact table using this key.

Let’s see the example

We are taking “AdventureWorksDW2019” database for this demo

“FactInternetSales” is a fact table and it is surrounded by dimensions table.  

In the above diagram “FactInternetSales” is the fact table and others are dimension table like DimCustomer, DimDate, DimCurrency, DimProduct and etc.

DimProduct is a dimension table

  

ProductKey is the primary key which is referred in the FactInternetSales table.

Type of Dimension table

Ø  Slowly changing dimension

Ø  Rapidly changing dimension

Ø  Junk dimension

Ø  Inferred dimension

Ø  Degenerate dimension

Ø  Confirmed dimension

Ø  Role playing dimension

Ø  Shrunken dimension

Ø  Static dimension