Question

Your data engineering team runs an on-demand BigQuery project where analysts frequently write ad hoc queries. Last month a single mistyped query scanned 45 TB and caused an unexpected cost spike. Leadership wants a repeatable, automated guardrail that prevents any individual query from processing more than a set data volume, and rejects the query before it runs if it would exceed that limit. What should you implement?

Accepted Answer

Set a custom query quota (maximum bytes billed per query) as a default at the project level so queries estimated to exceed the threshold fail before execution.

Answer

Configure a BigQuery daily on-demand cost budget in Cloud Billing with an email alert at 90% of the monthly threshold.

Answer

Create a scheduled query that periodically checks INFORMATION_SCHEMA.JOBS and cancels any query that has already scanned too much data.

Answer

Move the project to a flat-rate reservation with a fixed slot baseline so runaway queries cannot increase cost.