ETL Testing Basic 5

Question 1

In ETL testing, 'data completeness' testing ensures that:

Accepted Answer

Every expected record from the source is present in the target with no missing rows or fields

Answer

Completeness testing checks that no records were silently dropped during extraction, transformation, or loading by comparing source and target counts and key values.

Question 2

Checksum testing in ETL is used to:

Accepted Answer

Verify data integrity by computing hash or sum values on source columns and comparing them to the target

Answer

A checksum (e.g., MD5 hash or column SUM) computed on source data and re-computed on the target catches any corruption or alteration introduced during ETL.

Question 3

Which ETL testing type verifies that a newly deployed ETL version produces results identical to the previous version for the same input data?

Accepted Answer

Regression testing

Answer

ETL regression testing reruns old input through the new ETL version and diffs the output against the previously validated baseline to catch unintended changes.

Question 4

In ETL, 'idempotency' means that:

Accepted Answer

Running the same ETL job multiple times produces the same target state as running it once

Answer

An idempotent ETL can be safely re-run (e.g., after a failure) without duplicating data or corrupting the target.

Question 5

Lookup transformation testing in ETL focuses on verifying that:

Accepted Answer

Reference data lookups return the correct mapped values and handle unmatched keys according to the specified default or reject rule

Answer

Lookup tests supply known input keys and confirm that the correct reference value is returned, and that missing keys are handled as specified (default, NULL, or reject).

ETL Testing - extract, transform, load Practice Test

ETL Testing - extract, transform, load Practice Test

ETL Testing Basic 5