Cloud Digital Leader Google Cloud Products and Services Practice Question
A company wants to migrate its on-premises PostgreSQL database to Google Cloud with minimal application changes. They need high availability and want to leverage AI-powered optimizations for performance. Which service should they choose?
⚠ Common exam trap
GCDL often tests the confusion between Cloud SQL and AlloyDB, where candidates may choose Cloud SQL for PostgreSQL due to familiarity, missing the AI-powered optimizations and higher performance of AlloyDB.
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 for PostgreSQL is a fully managed, PostgreSQL-compatible database service on Google Cloud that offers high availability and uses AI-powered optimizations for performance, such as adaptive caching and automated tuning. It is designed for minimal application changes because it is wire-compatible with PostgreSQL. This makes it the best fit for migrating an on-premises PostgreSQL database with high availability and AI-driven performance.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Bigtable
Why it's wrong here
Bigtable is a wide-column NoSQL database designed for massive analytical and operational workloads that require high throughput at low latency, but it does not support the relational features that PostgreSQL applications depend on, such as multi-row ACID transactions, SQL joins, foreign keys, and rich indexing. Migrating an existing PostgreSQL schema to Bigtable would require a complete data model redesign and rewriting all application queries, so it cannot serve as a direct PostgreSQL replacement.
- ✗
Cloud SQL for PostgreSQL
Why it's wrong here
Cloud SQL for PostgreSQL is a fully managed, PostgreSQL-compatible database service that provides a straightforward lift-and-shift migration path with automated backups, replication, and patching. However, it does not include the AI-powered optimizations that AlloyDB offers, such as an automatic columnar engine for analytical queries, adaptive query optimization, and predictive caching, which are specifically designed to accelerate hybrid transactional and analytical workloads beyond what traditional managed PostgreSQL can achieve.
- ✓
AlloyDB
Why this is correct
AlloyDB is purpose-built for PostgreSQL workloads and is fully PostgreSQL-compatible, enabling most applications to migrate without changing code or SQL syntax. It delivers enterprise-grade high availability and performance with a columnar engine that speeds up analytical queries, adaptive indexes that learn from access patterns, and AI-driven optimization features that automatically fine-tune database settings—capabilities that Cloud SQL and other managed PostgreSQL services lack, making it the correct answer for this scenario.
- ✗
Cloud Spanner
Why it's wrong here
Cloud Spanner is a globally distributed, horizontally scalable relational database that provides strong consistency and external consistency, but it uses Google's proprietary SQL dialect rather than full PostgreSQL compatibility. Migrating a PostgreSQL application to Cloud Spanner requires rewriting SQL queries, converting data types, replacing stored procedures, and adjusting transaction semantics, which is a significant effort and deviates from the stated goal of a straightforward PostgreSQL migration.
Go deeper
Related to this question
Learn chapter
Building a Data-Driven Culture
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.
Key term
AlloyDB
AlloyDB is a fully managed, PostgreSQL-compatible database service from Google Cloud designed for high performance, scalability, and reliability for transactional and analytical workloads.
About these practice questions
This GCDL question is part of Courseiva's 848-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
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.