ETL Testing Trivia 2

Question 1

What does the acronym 'ETL' stand for in data warehousing?

Accepted Answer

Extract, Transform, Load

Answer

ETL stands for Extract, Transform, Load — the three-phase process of moving data from source systems into a data warehouse.

Question 2

Which type of ETL testing verifies that no records are lost or duplicated during the data movement process?

Accepted Answer

Data completeness testing

Answer

Data completeness testing checks that all expected records from the source arrive intact in the target without loss or duplication.

Question 3

In ETL terminology, what is a 'staging area'?

Accepted Answer

A temporary storage zone between source and target

Answer

A staging area is an intermediate, temporary storage location where raw extracted data is held before transformations are applied.

Question 4

Which ETL testing technique compares row counts between the source and target to detect data loss?

Accepted Answer

Reconciliation testing

Answer

Reconciliation testing compares aggregate counts and sums between source and target to confirm no data was lost or added during the ETL process.

Question 5

What is the primary purpose of a 'lookup transformation' in an ETL pipeline?

Accepted Answer

To match source data against a reference dataset to enrich or validate records

Answer

A lookup transformation queries a reference table or dataset to find matching rows, enabling data enrichment or validation against known values.

ETL Testing - extract, transform, load Practice Test