BigQuery’s New Cost Controls Are Here to Help

Because have you not met someone or heard some story about a runaway big query bill?

TL;DR: BigQuery is giving you a budget babysitter. It'll stop your queries from running wild with your credit card, but you're still the parent in charge.

Image: Imagen3 via Gemini. A pink piggy bank with coins going into it with a data center backdrop

If you’ve ever felt a slight pang of anxiety before running a massive query in BigQuery, you’re not alone - this is literally me, even if I know the query is only costing me cents. The fear of an accidental cost explosion is too real. But now you can be calm my young padawans, because Google Cloud is rolling out some welcome changes to BigQuery's cost management for on-demand queries, designed to give you more control and prevent those heart-stopping moments of bill shock.

Starting from 1 September 2025, BigQuery is introducing some sensible defaults and improved visibility to help you manage your on-demand compute costs more effectively. Let's break down what's changing and what it means for you.

What’s New on the Block?

The biggest change is to the QueryUsagePerDay and QueryUsagePerUserPerDay quotas. Previously, these could be set to "unlimited," which, while flexible, also left the door wide open for unintentional overspending.

Here’s the lowdown on the new setup:

• Finally, Sensible Defaults for New Projects: Any new project you create after 1 September 2025 will have a default QueryUsagePerDay quota of 200 TiB. This provides a generous baseline while still putting a cap on runaway queries.

• Smarter Limits for Existing Projects: For your existing projects currently set to "unlimited," Google Cloud will automatically apply a new custom limit. This limit will be based on your peak usage over the last 30 days, with enough extra room to accommodate your workload's growth. This tailored approach means you get a realistic and practical quota without having to figure it out from scratch.

• On-Demand Focus: It's important to note that these quota changes will only apply to on-demand usage. So, if you're using other BigQuery pricing models, these specific changes won't affect you.

What Stays the Same?

While these new cost controls are a big step forward, some things are thankfully staying the same:

• Your Custom Limits are Safe: If you've already set custom quota values for QueryUsagePerDay and QueryUsagePerUserPerDay, don't fret! Your existing settings will remain untouched.

• You're Still in the Driver's Seat: You'll continue to have full control to adjust your quota limits whenever you need to. You can easily tweak them through the Google Cloud Console, the Cloud Quotas API, or the gcloud CLI.

What Do You Need to Do?

To make the most of these new changes, it's a good idea to take a moment to review your current setup. Have a look at your project's daily on-demand query processing history to get a handle on your typical usage. This will help you determine if the new system-defined limits are a good fit or if you need to set your own.

Consider setting up usage alerts for your new limits using Cloud Monitoring. This way, you'll get a heads-up before you hit your quota, giving you time to adjust your queries or your limits as needed.

These upcoming changes are a positive move towards more predictable and manageable BigQuery costs. By providing smarter defaults and maintaining user control, Google Cloud is letting you to explore your data without the constant worry of an unexpected bill. So go ahead, query with confidence!