A company uses BigQuery for large-scale analytics. They have a fixed monthly budget and want to ensure predictable costs for query processing, even when many users run concurrent queries. Which BigQuery pricing model should they use?
Flat-rate pricing with slot reservations provisions dedicated query-processing capacity for a fixed monthly fee, decoupling cost from query volume. This satisfies the stem's requirement for predictable spend under concurrent workloads, unlike on-demand pricing, which scales with bytes processed.
Why this answer
Flat-rate pricing with slot reservations is correct because it provides a fixed monthly cost for a committed number of slots, making query processing costs predictable regardless of concurrent query volume. This aligns with a fixed budget and many concurrent users, since slots are dedicated capacity rather than per-query billing.
Exam trap
PCA often tests the difference between on-demand and flat-rate pricing — candidates pick autoscaling or committed-use discounts, but only flat-rate reservations give a truly fixed monthly cost.
How to eliminate wrong answers
Option A is wrong because on-demand pricing with flat-rate discounts is not a real BigQuery model; on-demand is per-TB scanned and inherently variable. Option B is wrong because autoscaling slot reservations adjust capacity dynamically, which can increase costs beyond a fixed budget. Option D is wrong because on-demand pricing with committed use discounts still bills per query and does not guarantee predictable monthly costs under concurrent load.