What are Fact and Dimension tables?

Wednesday, January 27, 2010

Overview
• A multidimensional storage model involves two kind of tables:
1. Dimension tables
2. Fact tables
Fact Tables: A fact table contains the fact data of business like sales amount, quantity, customers and reference keys to dimension tables.



· Dimension Tables:
· A dimension table holds the data that we use to group the value to derive summary.
· A dimension table has primary key.
E.g. Customer table has information about city, state and zip code to summaries geographically sales. A dimension table contains the more detailed information of fact data like product details, customer details, store details etc.


· The fact table mainly holds transaction data.
· E.g. fact table data shows units amount and sold quantities.