ETL Testing ETL Data Transformation Rules 2

Question 1

When testing ETL aggregation transformations, which validation is MOST critical?

Accepted Answer

Verifying that SUM, COUNT, and AVG results match independently calculated totals

Answer

Aggregation test results must be reconciled against independently computed totals to confirm the ETL grouping and calculation logic is accurate.

Question 2

What does 'data standardization' mean in the ETL transformation context?

Accepted Answer

Converting data to a consistent format, such as making all date formats YYYY-MM-DD

Answer

Data standardization ensures that data from diverse sources conforms to a uniform format, improving consistency and analytical accuracy in the target.

Question 3

In slowly changing dimension (SCD) Type 2 handling, what does the ETL transformation do when a source record changes?

Accepted Answer

Inserts a new row with the changed values and sets an expiry date on the old row

Answer

SCD Type 2 preserves history by expiring the current row and inserting a new version, allowing historical analysis of attribute changes over time.

Question 4

Which ETL transformation technique is used to combine first name and last name fields into a single full name column?

Accepted Answer

Concatenation

Answer

Concatenation combines multiple source fields into a single target field, such as merging first and last name into a full name.

Question 5

When testing a NULL-handling transformation rule that substitutes 0 for null numeric values, what test case is ESSENTIAL?

Accepted Answer

Send a record with a null numeric field and verify the target contains 0

Answer

The core test must confirm that a null input is correctly replaced by the default value (0), validating the null substitution rule.

ETL Testing - extract, transform, load Practice Test

ETL Testing - extract, transform, load Practice Test

ETL Testing ETL Data Transformation Rules 2