ETL Testing ETL Data Transformation Rules

Question 1

What is 'data cleansing' in the ETL transformation phase?

Accepted Answer

Identifying and correcting inaccurate, incomplete, or duplicate records

Answer

Data cleansing during transformation removes or corrects dirty data such as nulls, duplicates, and invalid formats before it reaches the target.

Question 2

In ETL testing, a 'mapping document' is primarily used to:

Accepted Answer

Define how source fields are transformed and mapped to target columns

Answer

The ETL mapping document specifies the source-to-target column mappings, transformation logic, and business rules that testers validate against.

Question 3

Which transformation type converts a value from one unit to another, such as converting temperatures from Celsius to Fahrenheit?

Accepted Answer

Calculation/Derivation transformation

Answer

Calculation or derivation transformations apply mathematical formulas to source values to produce new derived target values.

Question 4

What is 'surrogate key generation' in ETL transformation?

Accepted Answer

Assigning a system-generated unique integer key to each record in the data warehouse

Answer

Surrogate keys are artificial integer identifiers assigned by the ETL process to uniquely identify dimension records independent of source system keys.

Question 5

In ETL transformation testing, which test validates that a business rule such as 'sales amount cannot be negative' is enforced?

Accepted Answer

Business rule validation test

Answer

Business rule validation tests verify that transformation logic correctly enforces domain-specific constraints and business requirements.

ETL Testing - extract, transform, load Practice Test

ETL Testing - extract, transform, load Practice Test

ETL Testing ETL Data Transformation Rules