Data Warehousing Schemas

Example: Star Schema, Snowflake Schema, Fact Constellation Schema

Much like an OLTP system(database), an OLAP system(data warehouse) is also required to maintain a schema. A database uses an entity relational model, while a data warehouse uses a dimensional model. In this blog, we will see the three major schemas that are used to model a data warehouse.

About Star Schema

• Each dimension is represented by only one dimension table
• The dimension tables are directly linked with the fact table
• Queries are not that complex because of straightforward joins.
• Simple queries result in the faster query response time
• Most widely used in the industry

Example: Star Schema

As in this example, we have one fact(Sales) and four dimensions (Product, Time, Customer, Employee). The fact has measures like quantity, amount, discount, and payment.

About Snowflake Schema

• The dimension table is split into sub-dimension tables
• Some dimensions are normalized to…