ETL TESTING Study Guide 2026
Everything you need to pass the ETL TESTING exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 ETL TESTING Exam Format at a Glance
📚 ETL TESTING Topics to Study (21)
✍️ Sample ETL TESTING Questions & Answers
1. Which tool or approach is commonly used to generate large volumes of synthetic test data for ETL load testing in US data engineering teams?
Tools like Python's Faker library or web services like Mockaroo generate realistic synthetic data at high volumes for ETL load and stress testing without exposing real PII.
2. What is an 'ETL batch window'?
The batch window is the time slot — typically overnight — allocated for ETL processing; exceeding it delays data availability and can impact business operations.
3. Which extraction method reads only the data that has changed since the last extraction, minimizing load on source systems?
Incremental extraction captures only changed or new records since the last ETL run, reducing processing time and source system load.
4. Which ETL loading test validates that audit columns like 'load_date' and 'source_system' are correctly populated in the target?
Audit column tests confirm that ETL-generated metadata fields such as load timestamps and source identifiers are accurately set for every loaded record.
5. Which type of ETL testing tool compares query results between a legacy system and a new ETL pipeline to validate migration accuracy?
Parallel run testing runs both old and new pipelines simultaneously and compares their outputs to validate that the new ETL produces identical results before cutover.
6. What does 'online extraction' mean in ETL testing?
Online extraction pulls data from an active source system while it is still handling live transactions, requiring careful concurrency management.