Learn ETL Testing & Data Warehouse fundamentals (Udemy.com)

A hands-on tutorial that takes you from the ground up and gives you a solid understanding of Data Warehouse and ETL Testing concepts.

What will you learn from this course?

• Learn why and where ETL is required with a real-time business problem.

• Understand the fundamentals of Data Warehousing and common data models such as Star Schema.

• Gain a complete architectural overview of how ETL works with a Data Warehouse.

• Get an overview of popular ETL tools used in the industry.

• Build a real-time ETL project from scratch using Pentaho Data Integration (PDI) tool.

• Understand the scope of ETL testing at each layer of the pipeline with practical examples.

• Learn how to build ETL test scenarios and validate them using SQL queries.

• Write test cases for advanced concepts such as Slowly Changing Dimensions (SCDs).

• Explore Cloud Data Warehouses and how ETL/ELT fits in modern data stacks.

• Understand the differences between ETL vs ELT and where each is applicable.

• Discover the critical role of ETL data quality testing in training Large Language Models (LLMs) — ensuring reliable and accurate data pipelines is a key foundation for any AI/ML system.

• Learn how bad data quality can lead to hallucinations, bias, and inaccurate results in LLM outputs, and why robust ETL testing is crucial before model ingestion.

Prerequisites:

• Basic knowledge of SQL (Insert, Update, Delete).

• Core SQL concepts such as Joins, Group By, and Subqueries are used frequently in ETL test scenarios.

• A refresher on these SQL topics is available in the last section of the course — recommended for those who need it.