Data Warehouse (Cont.)


Schemas in Data Warehouses
Schemas are ways in which data is organized within a database or data warehouse. There are two main types of schema structures, the star schema and the snowflake schema, which will impact the design of your data model.

Star schema: This schema consists of one fact table which can be joined to a number of denormalized dimension tables. It is considered the simplest and most common type of schema, and its users benefit from its faster speeds while querying.

Snowflake schema: While not as widely adopted, the snowflake schema is another organization structure in data warehouses.

In this case, the fact table is connected to a number of normalized dimension tables, and these dimension tables have child tables. Users of a snowflake schema benefit from its low levels of data redundancy, but it comes at a cost to query performance.