In last few tutorial , we started talking about various Type of dimension in Data ware house and what role they play in data warehouse.Last time we talked about Conformed dimension and Junk Dimension . . Data warehouse mainly consists of Dimension and Fact tables. In below article we will go through the Degenerate Dimension in dataware house with some example , why they are important.Hope you will enjoy this small data warehouse tutorial.
Degenerate Dimension in Data warehouse
A Degenerate dimension is a Dimension which has only a single attribute. This dimension is typically represented as a single field in a fact table.The data items thar are not facts and data items that do not fit into the existing dimensions are termed as Degenerate Dimensions.
For example : In below Fact Table with customer_id, product_id, bill_no, date in key section and price, quantity in measure section. In this fact table, bill_no from key section is a single value, it has no associated dimension table. Instead of creating a separate dimension table for that single value, we can include it in fact table to improve performance. So here the column, bill_no is a degenerate dimension or line item dimension. -
I found a good article on Degenerate dimension in data ware house here
I also found some good article on other various type of dimension as well.
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