Cloud Digital Leader Google Cloud Products and Services Practice Question

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.

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