ADA-C01 Question 408
Single answerDetermine when warehouses should be suspended or resumed based on cost and pricingA company runs an ELT pipeline every 20 minutes. Each run submits several short queries that complete in about 30-40 seconds, and then the warehouse is idle until the next cycle. The team uses a dedicated X-SMALL virtual warehouse and wants to reduce compute cost without delaying the start of each pipeline run. Which configuration best aligns with Snowflake warehouse billing behavior and cost optimization best practices?
- A
Set AUTO_SUSPEND to 60 seconds and AUTO_RESUME to TRUE on the warehouse.
- B
Disable AUTO_SUSPEND so the warehouse stays warm between runs and avoids repeated startup charges.
- C
Set AUTO_SUSPEND to 5 seconds and AUTO_RESUME to FALSE so the scheduler can control all warehouse activity explicitly.
- D
Increase the warehouse size to SMALL and keep it running continuously, because larger warehouses are billed more efficiently for intermittent workloads.
Show answer and explanation
Correct answer: A
Explanation
The key pricing concept is that Snowflake bills virtual warehouses with a 60-second minimum each time a warehouse starts or resumes, and then per-second thereafter. Therefore, administrators should compare the cost of repeated resumes against the cost of leaving a warehouse running while idle. For a workload that runs briefly every 20 minutes, the idle time is substantial, so suspending the warehouse soon after activity ends is the cost-efficient choice. Enabling AUTO_RESUME ensures jobs can start without manual intervention. Snowflake documentation and best practices for warehouse management emphasize using AUTO_SUSPEND and AUTO_RESUME to control cost for intermittent workloads, while recognizing the 60-second minimum charge when a warehouse resumes.
- A. Correct.
Correct. Snowflake charges compute for warehouse usage with a 60-second minimum each time a warehouse is resumed, after which billing is per-second. In a workload with 20-minute idle gaps, keeping the warehouse running wastes credits during the idle period. Setting AUTO_SUSPEND to 60 seconds allows the warehouse to stop shortly after work completes, while AUTO_RESUME=TRUE lets incoming pipeline queries start the warehouse automatically with minimal operational overhead.
- B. Incorrect.
Incorrect. This is a common misconception. Although frequent resumes can matter for extremely bursty workloads, a 20-minute idle gap is long enough that leaving the warehouse running would typically cost much more than paying another 60-second minimum on resume. Disabling AUTO_SUSPEND is generally not cost-effective for this pattern.
- C. Incorrect.
Incorrect. AUTO_RESUME=FALSE would require an external process to resume the warehouse before each run, increasing operational complexity and risking job failures or delays if the scheduler does not explicitly resume it in time. Also, setting AUTO_SUSPEND below 60 seconds does not avoid the 60-second minimum billing on resume, so this does not provide a practical advantage here.
- D. Incorrect.
Incorrect. Increasing the warehouse size raises the credit consumption rate. For short, intermittent workloads with long idle periods, running a larger warehouse continuously is usually more expensive, not less. Larger warehouses may be appropriate for performance reasons, but not as a primary strategy for reducing cost in this scenario.