PCD Deploy Scalable and Highly Available Databases in Google Cloud Practice Test 3 — 15 Questions

Question 1

An organization runs a MySQL database on Cloud SQL. They want to ensure that all connections to the database are encrypted. Which action should they take?

Accepted Answer

Set the 'require_ssl' flag on the Cloud SQL instance to 'on'. Enabling the 'require_ssl' flag ensures that only SSL/TLS connections are accepted, enforcing encryption for all client connections.

Answer

Use the Cloud SQL Auth Proxy

Answer

Enable IAM database authentication

Answer

Create the instance with the '--require-ssl' flag

Question 2

A financial services company needs a globally distributed relational database with strong ACID transactions and high availability across regions. They anticipate unpredictable traffic spikes and need to pay only for the resources they use. Which Google Cloud database and scaling approach is most suitable?

Accepted Answer

Cloud Spanner with processing units and auto-scaling. Cloud Spanner provides global distribution, strong consistency, and ACID transactions. With fine-grained scaling using processing units and auto-scaling, it can automatically adjust capacity based on demand, optimizing cost.

Answer

Cloud SQL for PostgreSQL with cross-region replication

Answer

Bigtable with replication

Answer

Cloud Spanner with node-based scaling and manual resizing

Question 3

A company is using Cloud Bigtable to serve real-time analytics. They notice that some queries are slow, and the Key Visualizer shows a narrow row key range receiving the majority of reads and writes. What is the most likely cause and recommended action?

Accepted Answer

A single row key prefix is being accessed heavily, causing a hot spot; redesign the row key to distribute load. Hot spotting occurs when a small range of row keys is heavily accessed, causing uneven load distribution. Using a well-distributed row key design (e.g., salting) is the recommended solution.

Answer

The cluster has too few nodes; add more nodes to the cluster

Answer

Enable replication to a secondary cluster to offload reads

Answer

The storage type is HDD; switch to SSD to improve latency

Question 4

A developer needs to connect a Cloud Run service to a Cloud SQL instance securely without managing SSL certificates or configuring IP allowlists. Which connection method should they use?

Accepted Answer

Use the Cloud SQL Auth Proxy. Cloud SQL Auth Proxy handles authentication and encryption automatically, and works with Cloud Run via Unix sockets or TCP without requiring IP allowlisting.

Answer

Directly connect using the instance's public IP with SSL

Answer

Use the Cloud SQL Connector library

Answer

Configure VPC peering and use private IP

Question 5

A company wants to deploy a database for a global application that requires strong consistency across continents, with the ability to handle millions of reads and writes per second. Which Google Cloud database should they choose?

Accepted Answer

Cloud Spanner. Cloud Spanner is the only globally distributed, strongly consistent relational database that can handle millions of operations per second across multiple continents.

Answer

Firestore

Answer

Cloud SQL

Answer

Cloud Bigtable

Question 6

You are configuring a Cloud SQL for PostgreSQL instance for high availability. The instance must have automatic failover in under 60 seconds and avoid any data loss. Which configuration meets these requirements?

Accepted Answer

Create a regional HA configuration with synchronous replication. Regional HA configures a primary and a standby in different zones within the same region, using synchronous replication to ensure no data loss and failover in under 60 seconds.

Answer

Use Cloud Spanner instead

Answer

Create a zonal HA configuration with asynchronous replication

Answer

Add a cross-region read replica and promote it on failure

Question 7

A startup is building a mobile app with Firestore. They need to ensure that only authenticated users can read and write their own data. Which Firestore security rule pattern should they use?

Accepted Answer

Allow read/write if resource.data.userId == request.auth.uid. Using request.auth.uid to match the document owner ensures users can only access their own data.

Answer

Allow read/write if request.auth != null

Answer

Allow read/write only if the document path contains the user's uid

Answer

Allow read/write only if request.resource.data.userId == request.auth.uid

Question 8

A company wants to deploy a non-relational database for a real-time bidding application that requires low latency (under 10ms) and high throughput (millions of requests per second). The data model is key-value with a timestamp component. Which Google Cloud database is most appropriate?

Accepted Answer

Cloud Bigtable. Cloud Bigtable is designed for high-throughput, low-latency key-value workloads with time-series data, such as real-time bidding.

Answer

Cloud Spanner

Answer

Firestore

Answer

Cloud SQL

Question 9

You are migrating a PostgreSQL database to Cloud SQL. The database currently uses custom functions and PostGIS extensions. The target must support these extensions. Which database version and tier should you choose?

Accepted Answer

Cloud SQL for PostgreSQL 15 with standard machine type. Cloud SQL for PostgreSQL supports PostGIS and custom functions. The machine type depends on performance needs, but any tier works as long as PostgreSQL is chosen.

Answer

Cloud SQL for MySQL 8.0 with highmem machine type

Answer

Cloud Spanner with PostgreSQL dialect

Answer

Cloud SQL for SQL Server 2019 with lightweight machine type

Question 10

A company runs a Cloud Spanner instance with 2000 processing units. They notice that the high-priority CPU utilization is consistently above 80% during peak hours. Which action should they take to improve performance?

Accepted Answer

Enable auto-scaling with a high-priority CPU target of 65%. Auto-scaling can adjust processing units based on high-priority CPU target. Manually increasing processing units or nodes also works, but auto-scaling is the recommended approach.

Answer

Enable read replicas to offload CPU

Answer

Reduce the number of processing units to save cost

Answer

Switch to node-based scaling and add 2 nodes

Question 11

A company is using Cloud Bigtable for a time-series application. They need to ensure that if one zone fails, the database remains available for reads and writes with minimal downtime. Which configuration should they use?

Accepted Answer

Add a secondary cluster in a different zone within the same region. Adding a secondary cluster in a different zone within the same region provides replication and automatic failover for both reads and writes.

Answer

Enable auto-scaling on the cluster

Answer

Use a development instance type

Answer

Use a single-cluster instance with SSD storage

Question 12

A company needs to secure their Cloud SQL for MySQL instance. They want to ensure that only applications running within their VPC can connect, and that all connections are encrypted. Which two steps should they take? (Choose two.)

Accepted Answer

Enable the 'require_ssl' flag. Using private IP restricts connections to the VPC, and enabling SSL enforcement ensures encryption. IAM authentication is additional but not required for VPC-only connectivity.

Answer

Use Cloud SQL Auth Proxy on the application side

Answer

Assign a public IP address to the instance

Answer

Enable IAM database authentication

Question 13

A company uses AlloyDB for PostgreSQL and needs to scale read traffic automatically. They also want to ensure the database remains available if the primary zone fails. Which two features should they use? (Choose two.)

Accepted Answer

Configure the cluster as a regional cluster with high availability. Read pool instances provide auto-scaling read replicas, and regional cluster with HA provides automatic failover across zones.

Answer

Deploy AlloyDB Omni on-premises

Answer

Use a single-zone cluster and rely on read replicas for HA

Answer

Enable cross-region replication

Question 14

An organization uses Cloud Spanner in a multi-region configuration. They want to monitor performance and identify potential bottlenecks. Which three metrics should they review? (Choose three.)

Accepted Answer

Read and write latency. Processing units utilization indicates capacity, read/write latency measures performance, and high-priority CPU target helps identify contention. Rows deleted is not a performance metric.

Answer

Disk bytes used

Answer

Rows deleted by deletes

Question 15

A company is deploying a new financial application on Google Cloud that requires strong consistency, global scale, and the ability to handle millions of transactions per second across multiple regions. The application data has a relational structure. Which database service should they choose?

Accepted Answer

Cloud Spanner. Cloud Spanner is the only Google Cloud database that provides global strong consistency, horizontal scaling, and relational schema support at massive transaction volumes. Cloud SQL is limited to a single region, Bigtable does not support relational data, and Firestore is document-based with limited transaction support.

Answer

Firestore

Answer

Cloud SQL for MySQL

Answer

Cloud Bigtable