ETL & Data Warehousing

25 min Beginner Friendly 5.4k learners

What is ETL? 🤔

ETL stands for Extract, Transform, Load. Think of it as a data factory's assembly line!

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Extract

Gathering raw data from various sources like databases and files.

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Transform

Cleaning, validating, and structuring the data to meet business rules.

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Load

Storing the finished, high-quality data into a target system like a data warehouse.

What is a Data Warehouse?

A Data Warehouse is like a giant library 📚 for all your company’s data. It brings together data from different systems (sales, marketing, finance) and organizes it for analysis and reporting.

Popular Warehouses: Snowflake, Amazon Redshift, Google BigQuery.

Advanced Concepts

  • Staging Area: A temporary kitchen where raw data is kept before cooking.
  • Star Schema: A design where one central fact table connects to smaller dimension tables.
  • OLAP: Online Analytical Processing – fast queries for business analysis.
  • ELT vs ETL: In cloud, data is often loaded first (ELT) and transformed later.

Practice Quiz

Test your understanding of ETL & Data Warehousing:

1. In ETL, what does "Transform" mean?
2. Which is a cloud data warehouse?
3. A star schema connects:
4. ELT differs from ETL because:
5. OLAP is used for:

Great Job! 🎉

Now that you understand ETL & Data Warehousing, explore Cloud Databases or continue with SQL Basics.