PDE Ingesting and Processing the Data Practice Question
A company needs to continuously synchronize customer data changes from an on-premises Oracle database to BigQuery for near-real-time analytics. The Oracle database has Change Data Capture (CDC) enabled. Which Google Cloud service should be used to stream these changes with minimal latency and schema evolution support?
⚠ Common exam trap
PDE often tests whether candidates recognize that Datastream is the purpose-built managed CDC service, while Dataflow+JDBC is a custom polling approach that candidates mistakenly equate with CDC.
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
✓
Use Datastream to stream CDC changes from Oracle to BigQuery
Datastream is Google Cloud's fully managed, serverless CDC and replication service that natively supports Oracle sources (via LogMiner or XStream) and BigQuery destinations. It streams changes with low latency, handles schema evolution automatically, and requires no pipeline code to maintain. This matches the requirement for minimal latency and schema evolution support.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Deploy a Dataflow pipeline with a JDBC source and Pub/Sub
Why it's wrong here
A JDBC source queries Oracle periodically, so it cannot consume the enabled CDC log and therefore misses intermediate changes between polls. It is tempting because Dataflow with Pub/Sub genuinely suits streaming ingestion, but only when a CDC connector such as Datastream feeds the change events rather than JDBC polling.
- ✗
Use Cloud SQL with a read replica and enable binary logging
Why it's wrong here
Cloud SQL is a managed MySQL, PostgreSQL and SQL Server service; it cannot host or replicate an on-premises Oracle database, and binary logging is a MySQL mechanism, not Oracle CDC. It would be correct for replicating a Cloud SQL for MySQL instance into BigQuery, not an Oracle source.
- ✗
Use Transfer Appliance to copy Oracle data periodically
Why it's wrong here
Transfer Appliance performs bulk offline transfer, so data arrives in batches rather than continuously, and it cannot read Oracle CDC change streams. It is the right choice for migrating very large datasets where network bandwidth is the constraint, not for near-real-time synchronisation.
- ✓
Use Datastream to stream CDC changes from Oracle to BigQuery
Why this is correct
Datastream provides native Oracle CDC replication, reading redo logs to stream changes into BigQuery with minimal latency. Its built-in schema evolution handling automatically propagates source DDL changes, satisfying the stem's requirement for continuous near-real-time synchronisation without custom extraction code.
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 |
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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 PDE 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 PDE exam.