How Do You Apply a BigQuery Reservation to a CDC Process?

PDE By islever Editorial Last updated

Short answer

D Create a BigQuery reservation for the project.

Question

You are running your BigQuery project in the on-demand billing model and are executing a change data capture (CDC) process that ingests data. The CDC process loads 1 GB of data every 10 minutes into a temporary table, and then performs a merge into a 10 TB target table. This process is very scan intensive and you want to explore options to enable a predictable cost model. You need to create a BigQuery reservation based on utilization information gathered from BigQuery Monitoring and apply the reservation to the CDC process. What should you do?
  1. Create a BigQuery reservation for the dataset.
  2. Create a BigQuery reservation for the job.
  3. Create a BigQuery reservation for the service account running the job.
  4. Create a BigQuery reservation for the project. Correct Answer

Key Takeaways

The question tests whether you know that BigQuery reservations are assigned to resources such as projects, folders, or organizations, not to datasets, individual jobs, or service accounts.

The correct answer is D: create a BigQuery reservation for the project, because BigQuery reservation assignments can only target projects, folders, or organizations. Community consensus strongly supports project-level assignment, despite confusion about job-level or service-account-level reservations.

Common mistake: Option B (job-level reservation) is the most common wrong answer because test-takers think a reservation can be tied directly to the CDC job; BigQuery does not support job-level reservations, and assignments must be made at the project level (or higher).

Expert Analysis

Why the Answer Is Correct

Option D is correct. BigQuery reservations are capacity commitments that must be assigned to a project, folder, or organization, as documented in the official BigQuery reservations guide. When a job runs in a project that is assigned to a reservation, it uses slots from that reservation. The CDC process runs in the BigQuery project, so assigning the reservation to that project is the correct way to apply it. Community comments [1] and [2] correctly state that reservation assignments are only possible for projects, folders, or organizations, and comment [3] points directly to the official assignmen documentation.

Why the Other Options Are Wrong

Option A (dataset) is invalid because reservations cannot be scoped to a dataset; they apply to the entire project or higher. Option B (job) is a common misconception because BigQuery does not let you create a reservation for a single job; you can only assign a reservation to a project and optionally filter by job type. Option C (service account) is sometimes suggested, as in comments [7] and [9], but standard BigQuery reservation assignments do not accept service accounts as the assignee. To isolate the CDC workload, you use the project-level assignment with a job-type filter (for example, QUERY or BACKGROUND), not a service-account assignment.

Community Comment Notes

The most useful comments—[1], [2], and [3]—explain that reservations are assigned to projects, folders, or organizations and cite the official documentation. Comment [2] helpfully quotes the key phrase: "assign projects, folders, or organizations to a reservation." Comment [7] and [9] argue for service account, but this is not supported for BigQuery reservations and is contradicted by the official docs. Comment [8] mentions job-level reservations, but that is also not a valid BigQuery assignment target. The majority of voters (69 for D) and the official documentation make the project-level assignment the correct choice.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

When solving BigQuery reservation questions, remember that assignment targets are project, folder, or organization—never dataset, job, or service account. If the question asks about a specific workload like CDC, select the project-level reservation and consider the job-type field to separate query jobs from background load jobs, which makes costs predictable without trying to reserve for the job itself.

Community Votes

D
71%
B
29%

71% of anonymous learners picked answer D. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 14 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 14

  1. Matt_108 👍 10 Answered D
    Option D, reservation can't be applied to resources lower than projects (only to Org, folders or projects)
  2. task_7 👍 7 Answered B
    Reserve assignments To use the slot capacity you purchased, assign projects, folders, or organizations to a reservation. When a job in a project runs, it uses slots from the assigned reservation. Resources can inherit roles from their parents in the resource hierarchy. Even if a project is not assigned to a reservation, it inherits the assignment from the parent folder or organization, if any. If a project does not have an assigned or inherited reservation, the job uses on-demand pricing. For more information about the resource hierarchy, see Organizing BigQuery Resources .
  3. raaad 👍 3 Answered D
    C or D ?? Option C (service account) allows you to target the reservation specifically to the CDC process or any other jobs run by that service account. This is particularly useful if you have multiple processes running in the project with different performance or cost requirements. Option D (project) applies the reservation across all jobs in the project, which is a broader approach. If the CDC process is the primary or sole job running in the project and you want all jobs to share the same reservation, then this option might be more straightforward.
  4. Anudeep58 👍 3 Answered D
    https://cloud.google.com/blog/products/data-analytics/manage-bigquery-costs-with-custom-quotas. Quotas can be applied on Project or User Level
  5. f74ca0c 👍 3 Answered D
    D- choose the correct project and apply the task type background:https://cloud.google.com/bigquery/docs/reservations-intro?hl=fr#assignments
Show 9 more comments
  1. Positron75 👍 3 Answered D
    https://cloud.google.com/bigquery/docs/reservations-intro#assignments
  2. GCP001 👍 3
    D. Reservation is on project, folder or organisation level.
  3. viciousjpjp 👍 2 Answered B
    The correct answer is B. Create a BigQuery reservation at the job level. Create a BigQuery reservation at the job level: This is the most suitable option. By creating a job-level reservation, you can allocate resources specifically to the CDC process and improve the accuracy of cost forecasting. Steps to create and apply a BigQuery reservation: Identify the job: Clearly identify the job that executes the CDC process. Create a reservation: Use the BigQuery console or API to create a reservation, specifying the job's label, query text, and other details. Apply the reservation: Assign the created reservation to the job that executes the CDC process.
  4. desertlotus1211 👍 1 Answered C
    Answer C provides the granularity you need. Answer D is for the entire project... however the question ONLY wants it for the CDC process - so service account is better. In BigQuery, reservations are assigned to "assignments", which can be: Project Folder Organization Service account
  5. m_a_p_s 👍 1 Answered D
    "When you create commitments and reservations, they are associated with a Google Cloud project." - https://cloud.google.com/bigquery/docs/reservations-intro#admin-project
  6. meh_33 👍 1
    Are these questions really useful andd coming in GDE Exam? Anyone appeared recently and passed ?
  7. scaenruy 👍 1 Answered D
    D. Create a BigQuery reservation for the project.
  8. SamuelTsch 👍 1 Answered B
    Option B provides a more granularity solution
  9. JyoGCP 👍 1 Answered D
    Option D

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