Cloud Digital Leader Google Cloud Products and Services Practice Question
A company has a batch processing job that reads data from Cloud Storage, transforms it, and writes to BigQuery. The job runs nightly and takes approximately 2 hours. The team wants to reduce costs by using a managed service that automatically provisions and de-provisions resources. Which service should they use?
⚠ Common exam trap
GCDL often tests the confusion between orchestration (Cloud Composer) and execution (Dataflow), and between serverless (Dataflow, Cloud Functions) and cluster-based (Dataproc) services — candidates must match the 'automatically provisions and de-provisions' requirement to Dataflow.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Dataflow
Dataflow is a fully managed, serverless Apache Beam service that automatically provisions and de-provisions workers based on the job's workload, making it the best fit for a nightly 2-hour batch job where the team wants to avoid managing infrastructure. It supports batch and streaming, integrates natively with Cloud Storage and BigQuery, and charges only for the resources used during execution. This aligns exactly with the requirement to reduce cost through automatic resource lifecycle management.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Cloud Composer
Why it's wrong here
Cloud Composer is a managed Apache Airflow service for orchestrating workflows; it schedules and coordinates jobs, but does not execute data transformations itself. For the described batch ETL job, Composer would need to invoke a separate data processing engine like Dataflow, adding operational complexity without contributing worker capacity or transformation logic.
- ✗
Cloud Functions
Why it's wrong here
Cloud Functions is a serverless compute service for event-driven, single-purpose code, with a maximum execution timeout of 9 minutes (1st gen) or 60 minutes (2nd gen)—both far below the required 2-hour runtime. Additionally, its memory and CPU limits make large-scale data transforms impractical, so it cannot handle reading, transforming, and writing multi-gigabyte datasets to BigQuery.
- ✓
Dataflow
Why this is correct
Dataflow, Google Cloud's fully managed stream and batch processing service, runs the job in batch mode using Apache Beam, automatically scaling workers based on input size and processing needs. It reads from Cloud Storage, applies the required transformation logic, writes to BigQuery with exactly-once semantics, and then scales to zero after completion, so you only pay for the active compute during those 2 hours.
- ✗
Dataproc
Why it's wrong here
Dataproc is a managed Hadoop/Spark service that requires you to provision and size a cluster even for sporadic batch jobs, leaving compute running until you explicitly stop it or set an idle timeout. While it can read from GCS and write to BigQuery via Spark connectors, this adds cluster management overhead and cost compared to Dataflow's fully automatic scaling and deprovisioning for this ETL pattern.
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
Go deeper
Related to this question
Learn chapter
BigQuery and Data Analytics
Key term
Cloud storage
Cloud storage is a service that lets you save data on remote servers accessed over the internet instead of on your computer's hard drive.
Key term
Service
A service is a software component or system that performs a specific function and is available to be used by other programs or users over a network.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Google Cloud exam blueprint
This GCDL practice question is part of Courseiva's free Google Cloud certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the GCDL exam.