ETL Testing ETL Performance and Scalability Testing

Question 1

What is the primary goal of ETL performance testing?

Accepted Answer

Measuring whether the ETL pipeline can process required data volumes within the defined processing window

Answer

ETL performance testing determines whether the pipeline can handle production data volumes within the available batch window (e.g., a nightly 4-hour window).

Question 2

What is an 'ETL batch window'?

Accepted Answer

The scheduled time period during which the ETL process must complete all data processing

Answer

The batch window is the time slot — typically overnight — allocated for ETL processing; exceeding it delays data availability and can impact business operations.

Question 3

Which metric is MOST commonly used to measure ETL throughput performance?

Accepted Answer

Rows processed per second (or records per minute)

Answer

Rows per second or records per minute quantifies how fast the ETL pipeline processes data, allowing comparison against throughput requirements and benchmarks.

Question 4

In ETL scalability testing, what does 'volume testing' involve?

Accepted Answer

Running the ETL pipeline with significantly larger datasets than normal to identify degradation points and bottlenecks

Answer

Volume testing loads the ETL pipeline with very large datasets — often 10x or 100x normal size — to expose performance cliffs, memory limits, and scalability bottlenecks.

Question 5

What ETL performance issue occurs when a single processing node becomes a bottleneck, slowing the entire pipeline?

Accepted Answer

Data skew

Answer

Data skew happens when data is unevenly distributed across partitions or nodes, causing some workers to process far more records than others and creating a bottleneck.

ETL Testing - extract, transform, load Practice Test

ETL Testing - extract, transform, load Practice Test

ETL Testing ETL Performance and Scalability Testing