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

Encrypting data before storage

Answer

Compressing data for faster loading

Answer

Converting data types to strings

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

Track server IP addresses

Answer

Document network topology

Answer

List all staging table indexes

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

Aggregation

Answer

Lookup transformation

Answer

Filter transformation

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

Creating a natural business key from source data

Answer

Encrypting the primary key field

Answer

Generating a hash of all columns for deduplication

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

Referential integrity test

Answer

Load performance test

Answer

Schema test

Question 6

What is a 'lookup transformation' in ETL?

Accepted Answer

A transformation that matches a source value against a reference table to retrieve corresponding values

Answer

A search across web APIs for reference data

Answer

A full table scan to verify row counts

Answer

A technique to locate duplicate records