# Data Modeling

* Data Modeling is a process to visualize the data warehouse.
* It helps to set standards in naming conventions, creating relationships between datasets, and establishing compliance and security.
* Most Complex phase in data warehouse design.
* Recollect Top - Down vs. Bottom - Up that decision plays a vital role.
* Data Modelling typically starts at the data mart level and then branches out to the data warehouse.
* Three popular data models for data warehouses
  * Star Schema
  * Galaxy Schema
  * Snowflake Schema
