Cloud Digital Leader Google Cloud Products and Services Practice Question
A company is migrating its on-premises PostgreSQL database to Google Cloud. They need a managed service that is fully compatible with PostgreSQL, offers high availability, and provides automated backups. Which TWO Google Cloud services should they consider?
⚠ Common exam trap
GCDL often tests the confusion between Cloud SQL and AlloyDB, where candidates might think AlloyDB is not PostgreSQL-compatible or that Cloud SQL is not fully managed, when in fact both are valid options for PostgreSQL migration.
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
✓
Cloud SQL
Cloud SQL (A) is correct because it is a fully managed relational database service that supports PostgreSQL with full compatibility, offers high availability through regional configurations with automatic failover, and provides automated backups and point-in-time recovery. AlloyDB (C) is also correct because it is a fully managed PostgreSQL-compatible database service designed for high availability with a multi-node architecture and automated backups, while offering enhanced performance for demanding workloads. Memorystore (B) is incorrect because it is a managed in-memory data store for Redis and Memcached, not a PostgreSQL-compatible relational database. Filestore (D) is incorrect because it is a managed network file storage service (NFS) for file-based workloads, not a database service. Cloud Bigtable (E) is incorrect because it is a fully managed NoSQL wide-column database, not PostgreSQL-compatible.
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 SQL
Why this is correct
Cloud SQL is a fully managed relational database service that supports PostgreSQL, providing automated backups, point-in-time recovery, and high availability with synchronous replication across zones. It offers native PostgreSQL compatibility, so applications can migrate without any changes to their SQL or data access layer. With managed maintenance, scaling, and built-in security features like IAM integration and encryption at rest, Cloud SQL is the pragmatic default choice for most PostgreSQL migrations to Google Cloud.
- ✗
Memorystore
Why it's wrong here
Memorystore is a fully managed in-memory cache service that offers the Redis and Memcached protocols, engineered for low latency and high throughput as a cache or message broker. It does not provide a relational data model, SQL engine, or ACID transactions, and its primary storage is ephemeral unless persistence is explicitly enabled, which still does not make it PostgreSQL-compatible. Therefore, it cannot be used as the target for migrating an on-premises PostgreSQL database; it could only serve as a cache in front of a real database.
- ✓
AlloyDB
Why this is correct
AlloyDB is a fully managed, PostgreSQL-compatible database service built on Google Cloud's infrastructure, offering significantly higher performance than standard PostgreSQL through a columnar accelerator and adaptive caching. It provides automated backups, continuous availability, and cross-region replication, making it ideal for enterprise workloads that demand both high transaction throughput and fast analytical queries on the same data. AlloyDB also supports the PostgreSQL wire protocol, so migrating from an on-premises database requires minimal effort, though it may offer more features and scalability than the organization actually needs.
- ✗
Filestore
Why it's wrong here
Filestore is a managed network file storage service that provides NFS mounts for compute instances, commonly used for shared filesystems in media processing, on-premises workload lift-and-shift, or content repositories. It is a file storage service, not a database, and offers no SQL engine, query processing, connection pooling, or transactional semantics, so it cannot serve as a replacement for a relational database. Choosing Filestore for a PostgreSQL migration would be a fundamental mismatch, as it supports neither the PostgreSQL wire protocol nor any relational data operations.
- ✗
Cloud Bigtable
Why it's wrong here
Cloud Bigtable is a NoSQL, wide-column database designed for low-latency analytical and operational workloads, not a relational SQL engine. It fails the requirement for full PostgreSQL compatibility because it does not support SQL joins, transactions, or PostgreSQL-specific data types. The option is tempting because Bigtable offers high availability and automated backups, but those features serve time-series or IoT use cases, not a relational database migration requiring ACID compliance and PostgreSQL syntax.
Go deeper
Related to this question
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Key term
Memorystore
A fully managed in-memory data store service that provides Redis and Memcached for caching, session storage, and real-time data processing.
Key term
Failover
Failover is the automatic switching to a backup system when the primary system fails, ensuring continuous operation and minimal downtime.
About these practice questions
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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 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.