What are the different layers of a data warehouse?

Data Warehousing Concepts

Aaren Stubberfield

Data Scientist

Layer overview - data source

Layer overview - data staging

Layer overview - data storage

Layer overview - data presentation

Data source layer

• All data sources for data warehouse

• Examples of data sources:

  • Transactional database
  • Log files
  • Spreadsheets

Data staging layer

• Layer extracts, transform, and clean data through ETL process
• Contains ETL process and storage tables

ETL process within data staging layer

• Extracted
• Business rules applied and cleaned
• Staging database often used
• Must be able to extract valid data
• Batch / full loading

Data storage layer

• Data is stored in warehouse and data marts
  • Data warehouse -> Data mart
  • Data mart -> Data warehouse

Data presentation layer

• Users interact with stored data
• Users:
  • Use BI (Business Intelligence) tools
  • Use data mining tools
  • Create direct queries

Summary

Let's practice!

Data Warehousing Concepts