- A
Cloud Composer
Why wrong: Cloud Composer is a workflow orchestrator for batch jobs, not real-time streaming.
- B
Datastream
Datastream captures CDC from Cloud SQL and can publish to Pub/Sub for real-time streaming.
- C
BigQuery Omni
Why wrong: BigQuery Omni is for cross-cloud analytics, not for real-time streaming to Bigtable.
- D
Cloud Functions
Why wrong: Cloud Functions is not designed for high-throughput streaming; it's more suitable for event-driven, lower-volume triggers.
- E
Dataflow
Dataflow can consume events from Pub/Sub and write to Bigtable, performing any necessary transformations.
Question 632 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 retail company uses Cloud SQL for transactional data, Cloud Bigtable for real-time inventory updates, and BigQuery for analytics. They want to build a real-time dashboard that shows current inventory levels across all stores, updated within seconds of a transaction. The dashboard will query Bigtable for the latest inventory count. Which TWO services should they use to stream transactions from Cloud SQL to Bigtable?
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 a serverless change data capture (CDC) and replication service that can continuously stream changes from Cloud SQL (including transactional data) to Bigtable. It captures inserts, updates, and deletes in near real-time, enabling the dashboard to reflect current inventory levels within seconds of a transaction.
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.
- ✗
Cloud Composer
Why it's wrong here
Cloud Composer is a workflow orchestrator for batch jobs, not real-time streaming.
- ✓
Datastream
Why this is correct
Datastream captures CDC from Cloud SQL and can publish to Pub/Sub for real-time streaming.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
BigQuery Omni
Why it's wrong here
BigQuery Omni is for cross-cloud analytics, not for real-time streaming to Bigtable.
- ✗
Cloud Functions
Why it's wrong here
Cloud Functions is not designed for high-throughput streaming; it's more suitable for event-driven, lower-volume triggers.
- ✓
Dataflow
Why this is correct
Dataflow can consume events from Pub/Sub and write to Bigtable, performing any necessary transformations.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the distinction between batch orchestration (Cloud Composer) and real-time streaming (Datastream/Dataflow), leading candidates to incorrectly choose Composer for a CDC requirement.
Detailed technical explanation
How to think about this question
Datastream uses log-based CDC, reading the Cloud SQL binary logs (e.g., MySQL binlog or PostgreSQL WAL) to capture row-level changes without impacting source performance. It can stream directly to Bigtable via a Dataflow template, which handles schema mapping and row-key design for low-latency lookups. In a real-world scenario, a retail chain with thousands of stores might use Datastream to capture every inventory decrement from Cloud SQL and write to Bigtable, ensuring the dashboard shows sub-second stale data.
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
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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 a serverless change data capture (CDC) and replication service that can continuously stream changes from Cloud SQL (including transactional data) to Bigtable. It captures inserts, updates, and deletes in near real-time, enabling the dashboard to reflect current inventory levels within seconds of a transaction.
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.
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