Star Schema Modelling
A Dimensional modelling technique in which a detail fact table is linked to dimension tables.
The information contained in the data warehouse/data mart must be easy for the end-user to use and access. Denormalized designs are easier for end-users to use than highly normalized designs, however these designs are more difficult to design and maintain.
The Star Schema diagram graphically models the end-user's view (i.e., the denormalized view) of how the information is accessed.
Components of a Star Schema Diagram
The diagram has three main components:
· Fact Table and its contents: metric attributes and the foreign keys necessary to join to the dimension tables,
· Dimension Tables and their contents: reference attributes, hierarchical attributes, and metric attributes. The dimension tables are highly denormalized,
· The lines that link the Dimension Tables to the Fact Table.
Star Schema Model
This diagram is a model of a star schema diagram.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiNUxm7TzgIk93-EWUI5KY6PGyxKpqJlXuI3YBLBugxg6LPoPZJX4ZB7-o5NBN-i1tXilkADJ6STKLoLmcg3OXCTX2Abg6G33UQXDd_I2eNhJAe4qJYlFNT2Ivb-vhejXMWYd5JMEFHgTM/s400/star+scema+model.jpg)
Star Schema Example
The following is an example of a star schema for sales items.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0wRly8ULfpJrH9eot_FbmEkNjRX5ceZ3YZLeP0zinYT72_AhmyJ1XzBGWBM7KDoMqVGj9KdS08DvssDiMR_B_9IRdT1r2N-aKTSb_4z3LB1m_CVobVuP1vshATfX7hgjkf-EBoMH4IiM/s400/star+schema+example.jpg)
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