- A
Datastream
Datastream captures CDC from Oracle and streams to Pub/Sub.
- B
Cloud Pub/Sub
Pub/Sub is the messaging layer between Datastream and Dataflow.
- C
Dataflow
Dataflow reads from Pub/Sub, applies transformations, and writes to BigQuery.
- D
Cloud Scheduler
Why wrong: Cloud Scheduler is for scheduling, not streaming.
- E
Cloud Functions
Why wrong: Cloud Functions are not designed for complex transformations on streaming data.
Question 654 of 980
PCD Practice Question: Manage a Solution that Can Span Multiple Database Systems
This PCD practice question tests your understanding of manage a solution that can span multiple database systems. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company needs to synchronise data from an on-premises Oracle database to BigQuery in near real-time. They also need to perform complex transformations on the data before loading into BigQuery. Which two services should they use together? (Choose two.)
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
✓
Datastream
Datastream is correct because it provides serverless change data capture (CDC) from Oracle databases, enabling near real-time synchronization to BigQuery. Dataflow is correct because it can consume the Datastream output and perform complex transformations (e.g., joins, aggregations, schema mapping) using Apache Beam before writing to BigQuery.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Datastream
Why this is correct
Datastream captures CDC from Oracle and streams to Pub/Sub.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
Cloud Pub/Sub
Why this is correct
Pub/Sub is the messaging layer between Datastream and Dataflow.
Related concept
Read the scenario before looking for a memorised answer.
- ✓
Dataflow
Why this is correct
Dataflow reads from Pub/Sub, applies transformations, and writes to BigQuery.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Cloud Scheduler
Why it's wrong here
Cloud Scheduler is for scheduling, not streaming.
- ✗
Cloud Functions
Why it's wrong here
Cloud Functions are not designed for complex transformations on streaming data.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that Cloud Pub/Sub alone can perform transformations, but Pub/Sub is a messaging bus and cannot execute complex data processing logic; Dataflow is required for that purpose.
Detailed technical explanation
How to think about this question
Datastream uses Oracle LogMiner or direct redo log access to capture row-level changes with minimal latency, outputting to Cloud Storage or Pub/Sub. Dataflow can read from Pub/Sub (or directly from Datastream's output) and apply stateful transformations like windowing and sessionization, ensuring exactly-once semantics for BigQuery writes via the BigQuery I/O connector.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A cloud solutions architect for a retail company is evaluating services for a new workload. The correct answer here reflects best practice for the specific scenario described — not a general cloud recommendation. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Cloud exam questions reward reading the constraint carefully: the same technology can be right or wrong depending on the use case.
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 |
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Manage a Solution that Can Span Multiple Database Systems — study guide chapter
Learn the concepts, then practise the questions
- →
Manage a Solution that Can Span Multiple Database Systems practice questions
Targeted practice on this topic area only
- →
All PCD questions
980 questions across all exam domains
- →
Google Professional Cloud Developer study guide
Full concept coverage aligned to exam objectives
- →
PCD practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related PCD practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Manage a Solution that Can Span Multiple Database Systems practice questions
Practise PCD questions linked to Manage a Solution that Can Span Multiple Database Systems.
Deploy Scalable and Highly Available Databases in Google Cloud practice questions
Practise PCD questions linked to Deploy Scalable and Highly Available Databases in Google Cloud.
Design Scalable and Highly Available Cloud Database Solutions practice questions
Practise PCD questions linked to Design Scalable and Highly Available Cloud Database Solutions.
Migrate Data Solutions practice questions
Practise PCD questions linked to Migrate Data Solutions.
Designing highly scalable, available, and reliable cloud-native applications practice questions
Practise PCD questions linked to Designing highly scalable, available, and reliable cloud-native applications.
Building and testing applications practice questions
Practise PCD questions linked to Building and testing applications.
Deploying applications practice questions
Practise PCD questions linked to Deploying applications.
Integrating Google Cloud services practice questions
Practise PCD questions linked to Integrating Google Cloud services.
Managing application performance monitoring practice questions
Practise PCD questions linked to Managing application performance monitoring.
PCD fundamentals practice questions
Practise PCD questions linked to PCD fundamentals.
PCD scenario practice questions
Practise PCD questions linked to PCD scenario.
PCD troubleshooting practice questions
Practise PCD questions linked to PCD troubleshooting.
Practice this exam
Start a free PCD practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this PCD question test?
Manage a Solution that Can Span Multiple Database Systems — This question tests Manage a Solution that Can Span Multiple Database Systems — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Datastream — Datastream is correct because it provides serverless change data capture (CDC) from Oracle databases, enabling near real-time synchronization to BigQuery. Dataflow is correct because it can consume the Datastream output and perform complex transformations (e.g., joins, aggregations, schema mapping) using Apache Beam before writing to BigQuery.
What should I do if I get this PCD question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jul 4, 2026
This PCD 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 PCD exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.