PDE Storing the Data Practice Question
A company wants to run hybrid transactional and analytical workloads on a PostgreSQL-compatible database with high performance. Which service should they choose?
⚠ Common exam trap
Google often tests the distinction between 'PostgreSQL-compatible' and 'PostgreSQL-based' — candidates mistakenly choose Cloud SQL for PostgreSQL because it is a managed PostgreSQL service, but they overlook the specific requirement for hybrid transactional and analytical workloads, which AlloyDB uniquely addresses with its integrated columnar engine.
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
✓
AlloyDB
AlloyDB is the correct choice because it is a fully managed PostgreSQL-compatible database service specifically designed for high-performance hybrid transactional and analytical workloads. It combines transactional processing with built-in columnar analytics, delivering up to 4x faster transactional performance and up to 100x faster analytical queries than standard PostgreSQL, without requiring any schema changes or ETL.
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 Spanner
Why it's wrong here
Spanner is globally distributed but not specifically optimised for hybrid analytics.
- ✗
Cloud SQL for PostgreSQL
Why it's wrong here
Cloud SQL for PostgreSQL is PostgreSQL-compatible but vertically scaled, so it cannot deliver the high-performance analytical processing alongside transactional load that hybrid workloads demand. It is tempting because it is the natural PostgreSQL choice, and would be correct for a conventional transactional database without analytical scale requirements.
- ✗
BigQuery
Why it's wrong here
BigQuery is an analytical warehouse optimised for large-scale OLAP queries, not a PostgreSQL-compatible transactional engine, so it cannot serve the transactional half of the workload. It is tempting because it handles analytics superbly, and would be the right choice for a pure analytics or data-warehousing requirement.
- ✓
AlloyDB
Why this is correct
AlloyDB is a PostgreSQL-compatible, Google-managed database engine with a columnar acceleration engine that runs hybrid transactional and analytical workloads at high performance, satisfying both the PostgreSQL compatibility and HTAP constraints. Cloud SQL and standard PostgreSQL lack this integrated analytical acceleration.
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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.