Data Warehouse
Learn about data warehouses, the most common destination for ETL processes.
What is a data warehouse?
A data warehouse is a repository that stores historical data for analytical and BI purposes. Its main job is to copy data from the organization’s internal systems, such as databases, and store it in a specific way that allows the organization to use the data to support data-driven decision-making. Data warehouses are the main repository analysts and data scientists use when pulling data for their analytics jobs.
Data warehouses can read and write complex queries because of a modeling approach called dimensional modeling. In dimensional modeling, we organize the data in the data warehouse as a series of dimensions and facts. This allows users to quickly and easily query the data to generate reports and perform analysis.
Star schema
A star schema is a popular design choice in dimensional modeling and data warehousing. A data repository designed as a star schema will have a large de-normalized table called the fact table in the middle and will be surrounded by several smaller normalized tables called dimension tables.
Fact and dimension tables
The fact table will store the actual historical events/data, and the dimension tables will store information about the columns of the fact table. ...