ETL Testing ETL Data Extraction Techniques 3

Question 1

When extracting from a flat-file source (CSV), which test validates that all columns were parsed correctly?

Accepted Answer

Column count and header validation

Answer

Validating column count and header names ensures the file was delimited and parsed correctly, preventing column-shift errors.

Question 2

Which extraction strategy is preferred when regulatory compliance requires zero impact on source system performance?

Accepted Answer

Offline extraction from a read replica or backup

Answer

Extracting from a read replica or database backup ensures compliance-sensitive production systems experience no additional load.

Question 3

In ETL testing, 'data completeness' during extraction specifically checks for:

Accepted Answer

All expected records and fields being present in the extracted dataset

Answer

Data completeness validation confirms that all required rows and columns from the source were captured during extraction without omission.

Question 4

An ETL job extracts data from multiple source systems. Which test type ensures that records from all sources are correctly merged in staging?

Accepted Answer

Multi-source integration test

Answer

Multi-source integration testing validates that records from heterogeneous sources are properly combined, de-duplicated, and reconciled in the staging layer.

Question 5

What ETL test checks that special characters (e.g., accents, Unicode) in source data are preserved after extraction?

Accepted Answer

Character encoding validation

Answer

Character encoding validation ensures the extraction process correctly handles and preserves Unicode and special characters from source to staging.

ETL Testing - extract, transform, load Practice Test

ETL Testing - extract, transform, load Practice Test

ETL Testing ETL Data Extraction Techniques 3