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Design innovative, scalable, and highly available cloud database solutions

Practise Google Professional Cloud Database Engineer Design innovative, scalable, and highly available cloud database solutions practice questions — original exam-style scenarios with answer choices, explanations, and analysis of common mistakes.

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What to know about Design innovative, scalable, and highly available cloud database solutions

Cloud concepts questions usually test the service model (IaaS/PaaS/SaaS) and deployment model (public/private/hybrid/community) appropriate for a given scenario.

IaaS, PaaS and SaaS responsibilities and examples.

Public, private, hybrid and community cloud deployment models.

On-premises vs cloud trade-offs: cost, control, scalability.

How cloud connectivity options (VPN, Direct Connect, ExpressRoute) work.

Watch out for

Common Design innovative, scalable, and highly available cloud database solutions exam traps

  • IaaS gives you infrastructure control; SaaS gives you only the application.
  • Hybrid cloud combines on-premises and public cloud — not two public clouds.
  • Cloud does not automatically mean cheaper or more secure.
  • Management responsibility shifts with each service model (IaaSPaaSSaaS).

Question index

All Design innovative, scalable, and highly available cloud database solutions questions (141)

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1

A company is using Cloud Spanner and needs to add a new column to an existing table that has billions of rows. The column must have a default value of 0. The team is concerned about downtime. Which approach should they take to add the column with zero downtime?

Hard
2

An organization needs to run both transactional (OLTP) and real-time analytical (OLAP) queries on the same dataset without data duplication. The dataset is moderately large (a few terabytes). Which Google Cloud database service is MOST appropriate for this HTAP workload?

Medium
3

A data engineer is designing a schema for Cloud Spanner to store a hierarchy of customers and their orders. Customers have many orders, and queries often retrieve orders for a specific customer. To optimize performance and reduce cross-node reads, which schema design pattern should the engineer use?

Medium
4

A retail company uses Cloud Bigtable for real-time inventory. They want to improve read performance for queries that filter by product category and last_updated timestamp. Which THREE row key design strategies should they adopt? (Choose 3)

Medium
5

An online payment processing system uses Cloud SQL for MySQL with a 1 TB database. The system experiences high write throughput (~5000 writes/sec) and needs sub-10ms latency. The current instance has 8 vCPUs and 32 GB RAM. Which two metrics would indicate that the instance needs a larger tier? (Choose TWO.)

Hard
6

A company is designing a Cloud Bigtable schema for time-series data. The data is written by millions of devices every second. The query patterns are: (1) retrieve the most recent reading for a specific device, (2) retrieve all readings for a device in a time range. Which TWO row key design techniques should the team use to optimize for these patterns? (Choose two.)

Medium
7

A company is migrating an on-premises OLTP application to Google Cloud. The application requires high concurrency (up to 5,000 simultaneous connections) and uses a relational schema with strong transactional integrity. Which database service is the MOST suitable?

Medium
8

A company uses Cloud Spanner for its global inventory system. The current schema has a table 'Orders' with a primary key of OrderID (UUID). The team wants to add a secondary index to support queries filtering by 'status' and 'order_date'. Which type of index should they create and how should they define it to ensure the index covers the query without needing to read the base table?

Medium
9

A data engineer needs to run complex analytical queries on terabytes of data with sub-second query latency. The data is stored in Google Cloud Storage and updated daily. Which database service should they use?

Easy
10

A company is migrating from a relational database to Cloud Bigtable. They have a table with a 'user_id' and 'login_timestamp'. Queries often filter by user_id and time range. What should be the row key?

Medium
11

A team is migrating a MySQL OLTP database to Cloud Spanner. The existing schema uses auto-increment primary keys. They plan to convert them to STRING columns with UUIDs. However, the application also relies on ORDER BY on the original integer key. How should they preserve ordering while avoiding hotspots in Spanner?

Hard
12

A financial services firm needs a database for real-time fraud detection that requires single-digit millisecond latency for lookups on a precomputed feature set. The dataset is 5 TB and grows by 1 TB per month. Which database service BEST meets these requirements?

Medium
13

A company is migrating a monolithic application to a microservices architecture and plans to use multiple Google Cloud databases. The application has the following workloads: (1) user profiles with high read/write concurrency, (2) product catalog with complex queries, (3) session data that requires low-latency access. Which three Google Cloud databases should be used? (Choose three.)

Hard
14

You need to design a Cloud Bigtable row key for a time-series application that records user activity. The most common queries filter by user_id and then by timestamp (most recent first). Which row key design is MOST appropriate?

Medium
15

An engineer is designing a global inventory system that requires strong consistency across continents, with the ability to handle write conflicts and ensure ACID transactions. The system expects millions of reads and writes per second. Which Google Cloud database service meets these requirements?

Easy
16

A team is designing a Spanner schema for an online gaming leaderboard. The leaderboard stores player scores and requires high write throughput. Which primary key design is BEST to avoid write hotspots?

Medium
17

A data analyst needs to run a one-time SQL query on a dataset stored in CSV files in Cloud Storage. The query will scan the entire dataset, and the analyst wants to minimize cost. Which Google Cloud service should they use?

Easy
18

An organization uses Cloud SQL for PostgreSQL with read replicas to offload reporting queries. During peak, the primary instance's CPU spikes to 90%. The team suspects the read replica is falling behind. Which two settings should they check to diagnose replication lag? (Choose TWO.)

Hard
19

A company needs to store petabytes of time-series IoT sensor data and query it with single-digit millisecond latency at millions of reads per second. The data has a simple key-value structure with timestamps. Which Google Cloud database is MOST appropriate?

Medium
20

You are migrating a 5 TB MySQL database to Cloud SQL. The migration must have minimal downtime. Which THREE steps should you include in your migration plan?

Hard
21

A team is designing a Cloud Spanner schema for an e-commerce platform. They have 'Customer' and 'Order' tables and want to ensure that queries for all orders of a specific customer are efficient. Which schema design approach should they use?

Medium
22

A company uses Cloud Bigtable to store time-series data from IoT devices. Each device sends a reading every minute. The row key currently is: device_id + timestamp (e.g., 'device123#2024-01-01T00:00:00Z'). Write throughput is lower than expected. Which row key modification would MOST improve write distribution?

Medium
23

Which database service should you use if your workload requires complex JOINs, ACID transactions, and you want to avoid operational overhead of managing patching and backups?

Easy
24

A company runs a MySQL database on-premises and wants to migrate to Cloud SQL with minimal downtime. They have a multi-terabyte database. Which migration method is most appropriate?

Medium
25

You are designing a schema for Cloud Spanner and need to avoid write hotspots. Which primary key design strategy is recommended?

Easy
26

A company is designing a schema for Cloud Spanner for an order management system. They need to ensure efficient joins between Order and OrderItems tables. Which TWO design practices should they adopt? (Choose 2)

Medium
27

You are migrating a relational database to Cloud Bigtable. The source schema has a Users table and an Orders table with a one-to-many relationship. The application frequently queries all orders for a user. Which three Bigtable schema design practices should you apply?

Hard
28

A gaming company is designing a leaderboard using Cloud Spanner. The leaderboard updates scores in real time and supports queries for top players. Which THREE strategies should they implement to achieve high performance and avoid hotspots? (Choose 3)

Hard
29

A gaming company uses Cloud Bigtable to store player session data. The row key is player_id (UUID) and they have a column family 'sessions' with multiple columns per session. They want to query all sessions for a specific player in a given time range efficiently. Which row key design improvement should they consider?

Medium
30

A company is planning to use Cloud Spanner for a new global application. They estimate a peak write throughput of 10,000 mutations per second. What is the minimum number of processing units (PUs) required, given that each PU supports up to 2000 mutations/second?

Medium
31

A startup is building a mobile app with a relational database backend. They expect moderate traffic and need strong consistency, automatic backups, and point-in-time recovery. Which two Google Cloud database services meet these requirements? (Choose TWO.)

Easy
32

A company uses Cloud SQL for PostgreSQL and needs to add a full-text search capability to a table with product descriptions. Which index type should be used?

Medium
33

An engineer is configuring a Cloud SQL for PostgreSQL instance for an OLTP workload. The instance has 30 GB of RAM and expects up to 2000 concurrent connections. The default max_connections is 100. The engineer needs to set max_connections appropriately based on Google's recommendation. What should the max_connections be set to?

Hard
34

A team is designing a Bigtable schema for a real-time fraud detection system. The row key includes device ID and timestamp. They need to avoid hotspotting during high write periods. Which two row key design patterns help achieve this? (Choose TWO.)

Medium
35

A financial services company is migrating a legacy on-premises OLTP application to Google Cloud. The application requires high transaction rates (thousands per second), strict ACID compliance, and the ability to scale horizontally across multiple regions with strong consistency. Which Google Cloud database service should the company choose?

Easy
36

A company is migrating a large on-premise Hadoop workload to Google Cloud. The data is stored in HBase and consists of time-series logs with 10 PB of data. They need a fully managed NoSQL solution with high throughput and low latency. Which migration path should they choose?

Medium
37

A Cloud Spanner instance has a single node and is experiencing high write contention. The workload is 3000 writes per second with 2 KB mutations. Which two changes would improve write throughput? (Choose TWO.)

Medium
38

You are designing a Cloud Bigtable schema for a time-series application that stores temperature readings from sensors. Each reading has a sensor ID (string), a timestamp (microseconds), and a temperature value. Queries always filter by sensor ID and a time range. Which row key design is optimal?

Easy
39

A company needs a fully managed, relational database with strong consistency and global distribution for a travel booking application that supports high concurrency and ACID transactions. Which Google Cloud database should they choose?

Easy
40

An application uses Cloud SQL (MySQL) and experiences an increasing number of 'too many connections' errors. The current instance has 4 vCPUs and 15GB of RAM. The application's connection pool is configured for 500 connections. What should the engineer do to resolve this error?

Easy
41

A company is designing a Cloud Spanner database for a global supply chain application. The schema includes a table 'Shipments' with columns: shipment_id (INT64), created_at (TIMESTAMP), origin (STRING), destination (STRING), status (STRING). The application frequently queries for shipments by origin and status. Which three design choices optimize query performance? (Choose THREE.)

Hard
42

A startup is building a mobile app backend with high-concurrency user authentication and profile updates. They need strong consistency and ACID transactions. Which database service should they choose?

Easy
43

You are designing a Spanner schema for a global inventory system. The table Products has primary key (ProductId STRING). The table Inventory has primary key (ProductId STRING, WarehouseId INT64) and is interleaved in Products. You expect high write throughput on Inventory. Which TWO design choices will help avoid hotspots?

Medium
44

A company is migrating a relational database to Cloud Bigtable. The source schema has a customers table and an orders table with a foreign key. Which data model approach is recommended for Bigtable?

Medium
45

A manufacturing company uses Cloud SQL for PostgreSQL for its inventory system. The database has grown and now experiences high read latency. The team wants to improve read performance without changing application code. Which THREE actions should they consider? (Choose 3)

Medium
46

A company runs a financial analytics platform on BigQuery. They need to reduce query costs for frequent, predictable queries. Which three strategies can help? (Choose THREE.)

Hard
47

A company is building a real-time leaderboard for a mobile game using Google Cloud. The data includes player scores that update frequently (thousands of writes per second) and queries for top 100 players. Which database is most suitable?

Easy
48

You are designing a Spanner schema for a global social media application that stores user posts. Each user can have millions of posts. The most common query is 'get the most recent 10 posts for a user'. Which table interleaving design minimizes latency?

Easy
49

An e-commerce platform runs on Cloud SQL and expects heavy write traffic during a flash sale. The database instance currently has 8 vCPUs and 32 GB RAM. Based on the max_connections formula (max_connections = RAM_MB/16), what is the current maximum number of connections, and what change would increase it?

Medium
50

A company needs to migrate its on-premises Oracle database to a fully managed relational database on Google Cloud. The application uses stored procedures and requires high availability across multiple zones. Which migration path is MOST appropriate?

Medium
51

A company is using Cloud SQL for MySQL for its OLTP workload. They want to run complex analytical queries on the same data without impacting transactional performance. The analytical queries involve large scans and joins. What is the recommended approach?

Medium
52

An engineer is designing a Cloud SQL database for an e-commerce platform. They need to store product inventory and order history. Which schema normalization level is recommended for OLTP to avoid data anomalies?

Medium
53

You need to design a Spanner schema for a social media application that stores user posts. Each post has a unique ID, author ID, timestamp, and content. The primary access pattern is querying all posts for a given author in reverse chronological order. Which schema design minimizes the risk of hotspotting?

Hard
54

A company is migrating a large on-premises MySQL database to Cloud SQL. The source database supports heavy reporting queries that scan millions of rows and join multiple tables. The team wants to minimize downtime and avoid performance degradation during migration. Which migration approach should they use?

Hard
55

A company wants to migrate from a self-managed MySQL database to a fully managed GCP service. They need high availability with automatic failover, automated backups, and read replicas for scaling read traffic. Which two Google Cloud services meet these requirements? (Choose TWO.)

Easy
56

A company wants to store and analyze time-series metrics from thousands of servers. The data is write-heavy with occasional reads of recent data. They need low-latency writes and the ability to scan large ranges later. Which Google Cloud database is MOST appropriate?

Medium
57

An e-commerce platform uses Cloud Spanner as its database. The orders table has a monotonically increasing order_id as the primary key, and the team observes high write latency during peak hours. Which design change would BEST distribute write load across nodes?

Hard
58

You are designing a Bigtable schema for a time-series application that records sensor readings every second. Queries always filter by device ID and time range. To avoid hotspotting and ensure recent data is retrieved quickly, which row key design is MOST effective?

Hard
59

A team is designing a schema for Cloud Spanner to store user profiles. The primary access pattern is to read a user's profile by their unique user ID. To avoid write hotspots, which primary key design strategy should the team use?

Medium
60

A Cloud Bigtable instance stores high-volume time-series data. Write throughput is at node capacity, but read latency spikes occasionally. The row key pattern is 'timestamp#device_id'. Which optimization should be applied first?

Hard
61

A company is running analytical queries on large datasets (terabytes) that involve aggregations, joins, and window functions. The data is updated daily via batch loads. The queries must complete in seconds to minutes. Which Google Cloud database service is BEST suited for this workload?

Easy
62

A team is migrating a MongoDB application to Firestore. The data model includes embedded documents and references between collections. Which approach should they follow to maintain similar query performance?

Medium
63

A startup is building a real-time analytics dashboard that ingests 500,000 events per second and needs to query the last hour of data with sub-second latency. The data has a high write volume and the query pattern is time-range scans. Which Google Cloud database is most appropriate?

Medium
64

You are designing a Spanner schema for a financial application that stores transactions for user accounts. To avoid hotspots and optimize performance, which TWO practices should you follow?

Medium
65

A company is evaluating Google Cloud databases for a new application that requires: (1) strong global consistency across multiple regions, (2) the ability to run complex analytical queries on the same data as the transactional workload, and (3) high write throughput. Which TWO databases should they consider?

Medium
66

A company is designing a Cloud Spanner database for a global inventory system. The application runs OLTP transactions on inventory levels and also needs to generate daily reports that scan the entire inventory table. Which two approaches will reduce the impact of analytical queries on transactional performance?

Medium
67

A team is migrating a relational database to Cloud Bigtable. They need to design a row key that distributes write traffic evenly across nodes. The original table had a composite primary key of customer_id and order_date. Which row key design is BEST for high write throughput?

Medium
68

An e-commerce platform uses Cloud SQL for PostgreSQL with max_connections set to 500. They plan to increase the number of application instances requiring connections. The instance has 8 vCPUs and 32 GB RAM. What is the maximum number of connections Cloud SQL can support based on the default formula?

Hard
69

Which Google Cloud database service is designed for hybrid transactional and analytical processing (HTAP) with a built-in columnar engine?

Easy
70

A company is running a financial application on Cloud Spanner and needs to ensure strong transactional consistency across regions. The application requires both high write throughput (2000 mutations/second) and read throughput (2000 reads/second). According to Spanner capacity planning, how many processing units (PUs) are needed for the combined workload?

Medium
71

An engineer is designing a Cloud Spanner schema for a chat application where users send messages. Messages are ordered by timestamp per conversation. The primary key chosen is (ConversationId, MessageId) where MessageId is a monotonically increasing integer. What potential issue might arise with this key design?

Medium
72

A startup needs a database for its new web application that will serve a global user base. The application requires low-latency reads and writes (single-digit milliseconds), strong consistency, and the ability to handle high concurrency (thousands of transactions per second). Which Google Cloud database service should the startup choose?

Easy
73

An engineer is designing a Bigtable schema for a weather data application. The data is written by thousands of sensors, each generating a reading every minute. Queries typically retrieve all readings for a sensor in a time range. The row key should be designed to avoid hotspots and support these queries. Which two row key components are recommended? (Choose two.)

Easy
74

A global e-commerce platform expects 50,000 concurrent users during flash sales, each performing short transactions like adding to cart and checking out. The database must provide strong transactional consistency across regions. Which Google Cloud database is most appropriate?

Medium
75

A company is migrating an on-premise PostgreSQL database to Cloud SQL. The current database has a connection pool with 200 connections and uses 64 GB RAM. According to Cloud SQL best practices, what is the maximum recommended max_connections setting?

Hard
76

A company needs to run complex analytical queries on large datasets (petabytes) with SQL support and high scalability. The data is stored in CSV files in Cloud Storage. Which Google Cloud service is MOST suitable?

Easy
77

A global gaming company uses Spanner to store player profiles and scores. The most common query is 'Get the top 10 players by score' across all regions. The 'Players' table has millions of rows. Which schema design and query approach provides the best performance?

Hard
78

A company is migrating a MySQL OLTP database to Bigtable for a time-series application. The current schema uses a relational model with normalized tables. Which two actions should the team take when designing the Bigtable schema? (Choose TWO.)

Medium
79

A team is migrating a relational database to Bigtable. The existing schema uses foreign keys to join orders, customers, and products. Which data model approach is most suitable for Bigtable?

Medium
80

You are running a Cloud Spanner instance and notice that a secondary index is causing performance issues for write operations. The index includes all columns of the table. Which Spanner feature can reduce the storage and write overhead of the index?

Hard
81

A company uses Bigtable for time-series analytics and needs to query the most recent data points first. The row key currently consists of a user ID followed by a timestamp (e.g., user123#2024-01-15T10:30:00). However, frequent queries filter by time range across all users. Which row key design change would optimize query performance for this access pattern?

Hard
82

A company runs a MySQL database on Cloud SQL for an e-commerce platform. They need to add a new column to a table with millions of rows without causing downtime. What is the recommended approach?

Hard
83

A team is designing a Cloud Spanner schema for a global social media application. The table 'Posts' has a primary key of (UserId, PostId) where PostId is a UUID. They notice write hotspots on the server with monotonically increasing UserId values. What is the most effective schema design change to distribute writes evenly?

Hard
84

A startup needs a fully managed relational database for their e-commerce platform with high availability, automatic failover, and read replicas. They expect moderate traffic and want to minimize operational overhead. Which Google Cloud service should they use?

Easy
85

An organization needs a fully managed, globally distributed relational database with strong consistency and horizontal scaling for a multi-region application. Which service meets these requirements?

Easy
86

A company is designing a schema for Cloud Bigtable to store user sessions. Access patterns: (1) read all sessions for a given user ID, and (2) read a specific session by session ID. The row key should support both patterns efficiently. Which row key design is MOST appropriate?

Medium
87

An e-commerce platform uses Cloud SQL for PostgreSQL to manage orders. The application team reports that the database experiences performance degradation during peak hours due to high connection churn. They want to maintain a pool of established connections. Which configuration change addresses this without application code changes?

Medium
88

You are designing a Cloud SQL for PostgreSQL instance for an OLTP application. The application typically handles 500 concurrent connections and the working set is 8 GB. You estimate a buffer pool of 4 GB. What minimum memory allocation should you choose?

Medium
89

An organization is designing a Cloud Spanner schema for a social media application. The application frequently queries for all posts by a specific user, and also updates the number of likes on a post. To ensure high performance and avoid hotspots, which TWO schema design principles should the team apply? (Choose two.)

Medium
90

An organization uses Cloud Spanner and needs to add a new column to an existing table without downtime. The table has billions of rows and is heavily used. What is the recommended approach to add the column?

Hard
91

Which Spanner feature allows you to add a new column to an existing table without blocking writes or requiring a rebuild?

Easy
92

A company needs to store and analyze semi-structured JSON logs from multiple microservices. The data is write-heavy with bursts of 100,000 writes/sec, and queries filter by service name and timestamp range. They require low operational overhead and the ability to query with SQL. Which Google Cloud database should they choose?

Medium
93

You are designing a database schema for Cloud SQL (MySQL) for an OLTP application. Which normal form is typically recommended to avoid update anomalies?

Easy
94

A startup is building a ride-sharing application that requires globally distributed, strongly consistent transactions for ride matching and payments. The database must scale horizontally and provide low-latency reads and writes. Which Google Cloud database should they use?

Easy
95

You need to estimate the number of Bigtable nodes required for a workload of 50,000 reads per second (QPS) and 20,000 writes per second. Each node can handle 10,000 QPS for reads or writes. Storage is not a constraint. What is the minimum number of nodes required?

Hard
96

You are designing a schema for Cloud Spanner and need to model a one-to-many relationship between Customers and Orders. Which THREE features or practices should you consider? (Choose three.)

Easy
97

Which of the following is a benefit of using parent-child interleaved tables in Cloud Spanner?

Easy
98

You are designing a Bigtable schema for a messaging application where users have conversations. Each row represents a message with row key 'userID#conversationID#timestamp'. The application queries the most recent messages for a given conversation. How should you modify the row key to optimize for this query pattern?

Hard
99

A company uses Cloud SQL for MySQL and wants to run complex analytical queries on the same data without affecting OLTP performance. They need a solution with minimal data movement and low operational overhead. Which approach should they take?

Medium
100

A data engineering team needs to run complex analytical queries on terabytes of data stored in Cloud Storage. The queries are ad-hoc and require scanning large portions of the dataset. The team needs a serverless solution that optimizes for cost by charging only for the data processed. Which Google Cloud service should they use?

Medium
101

You are designing a Cloud Bigtable row key for a social media feed where users see posts from friends. Queries are: get posts for a user (by user_id) ordered by timestamp most recent first, and get posts for a specific topic (by topic_id) ordered by timestamp. To support both access patterns efficiently, which TWO design strategies are appropriate? (Choose two.)

Hard
102

A small business runs a MySQL OLTP database for their inventory management system. They need high availability with automatic failover and regional disaster recovery. Which Google Cloud database service meets these requirements with minimal operational overhead?

Easy
103

A data engineer is migrating a legacy on-premises Oracle data warehouse to Google Cloud. The source schema uses star schemas and advanced Oracle features like materialized views. The target must support real-time data from streaming sources and run complex SQL joins over 50 TB of data with low latency. Which architecture is most appropriate?

Hard
104

A company is migrating a monolithic application to Google Cloud and needs to modernize the database layer. The application has both OLTP (high-volume transactions) and OLAP (complex reporting) workloads. The team wants to use a single database to simplify operations but with high performance for both. Which TWO Google Cloud database services support hybrid transactional/analytical processing (HTAP)? (Choose two.)

Medium
105

A company needs to perform real-time analytics on streaming data from IoT devices with millisecond latency for alerts, and also run complex historical analytics. Which Google Cloud database architecture supports both?

Medium
106

You are designing a Cloud Bigtable schema for a time-series application where the most common write pattern is high-throughput writes (10,000 writes per second) and the row key starts with a timestamp. Write throughput is lower than expected. What is the most likely cause?

Medium
107

A company runs an e-commerce website on Cloud SQL. They want to scale read traffic without impacting write performance and need high availability across zones. Which configuration should they use?

Medium
108

A startup is building an IoT analytics platform that ingests sensor data at high velocity and needs to run real-time dashboards and ad-hoc queries on the data. Which TWO Google Cloud databases should they use together? (Choose 2)

Easy
109

A Cloud Spanner instance must handle 50,000 write mutations per second. You plan to use processing units (PUs). Each PU supports up to 2,000 mutations/second. What is the minimum number of PUs required?

Hard
110

A company uses Bigtable for time-series data with a row key format: 'deviceID#timestamp'. They notice write hotspotting on a few devices that generate high volumes of data. How should they redesign the row key to distribute writes evenly?

Medium
111

A data analyst needs to run ad-hoc SQL queries on a large dataset stored in Google Cloud Storage (CSV files). They do not want to manage any infrastructure. Which service should they use?

Easy
112

A gaming company uses Cloud Spanner to store player profiles and game state. The database has a table 'Players' with a monotonically increasing integer primary key. During a global launch event, write latency spikes and throughput drops. The issue is traced to hotspotting. Which schema change should the team implement to mitigate this?

Medium
113

You have a Cloud Spanner instance and need to add a new column and a secondary index to an existing table. The table is heavily used by production traffic. Which approach minimizes downtime and performance impact?

Hard
114

A team is migrating a legacy application from a relational database to Cloud Firestore. The existing schema has a Customers table and an Orders table with a foreign key. The application often shows orders for a customer. What is the recommended data modeling approach in Firestore?

Medium
115

A financial services company runs a high-frequency trading application that requires strong consistency, horizontal scalability, and low-latency transactions across multiple regions. Which Google Cloud database should they choose?

Easy
116

A company is migrating their on-premises Oracle OLTP workload to Cloud SQL for PostgreSQL. The database currently supports 500 concurrent connections and has a working set of 8 GB. What is the minimum memory required for the Cloud SQL instance based on the max_connections formula (max_connections = RAM_MB/16)?

Medium
117

A financial services company uses Cloud Bigtable to store transaction data. The row key is constructed as customer_id reversed timestamp. The team wants to retrieve the most recent 100 transactions for a specific customer quickly. Which row key design principle is being used to optimize this query?

Hard
118

A media streaming company is designing a database for user recommendations. They expect high write throughput for user interactions and need to run complex analytical queries on the same data for personalization. They want a fully managed solution with minimal latency for writes. Which TWO services can be combined to meet these requirements?

Medium
119

A company needs to store petabytes of time-series IoT sensor data and query it with single-digit millisecond latency at millions of reads per second. The data has a simple key-value structure with timestamps. Which Google Cloud database is MOST appropriate?

Medium
120

A company wants to run complex analytical queries on terabytes of sales data with sub-second query response times for dashboards. Data is updated frequently in near real-time. Which combination of services is most appropriate?

Medium
121

A company is designing a database solution for a global social media application that requires strong consistency, high write throughput, and complex relational queries. Which TWO Google Cloud databases should they consider? (Choose 2)

Medium
122

An engineer needs to migrate a MySQL database to Cloud SQL with minimal downtime. Which TWO steps should be part of the migration plan? (Choose 2)

Medium
123

You are planning a Cloud Bigtable cluster for a workload requiring 100,000 reads per second and 50,000 writes per second. The data will be stored on HDD. How many nodes are needed for the projected throughput? (Assume each node provides 10,000 QPS for reads or writes.)

Hard
124

You are designing a Cloud SQL for PostgreSQL database. The application has a table with 1 million rows that is frequently queried using equality on the 'email' column and range queries on the 'created_at' column. Which index strategy minimizes query latency?

Medium
125

A team is migrating a large on-premise Oracle database to Cloud SQL for PostgreSQL. They need to minimize downtime and ensure data consistency. Which migration approach is recommended?

Medium
126

A retail company is designing a new inventory management system on Cloud Spanner. They need to ensure high write throughput for order processing. Which two schema design practices help avoid write hotspots? (Choose TWO.)

Easy
127

A company is migrating a large relational database to Bigtable. The database has a table with columns: user_id (string), event_type (string), timestamp (timestamp), and details (JSON). The access patterns include retrieving all events for a user in a time range, and filtering by event_type. Which THREE row key design strategies should they apply? (Choose 3)

Hard
128

An engineer is designing a Bigtable row key for global user events. They want to avoid hotspots and enable efficient queries by user_id and time range. Which row key design is best?

Medium
129

A startup needs a database for a global user base with low-latency reads and writes, strong consistency, and the ability to scale horizontally without downtime. They anticipate variable traffic. Which Google Cloud database service meets these requirements?

Easy
130

An engineer is designing a Cloud Spanner table for a global user activity tracking system with high write throughput. Which primary key design is BEST to avoid hotspots?

Hard
131

A company wants to migrate a 5 TB MySQL database to Cloud Spanner with zero downtime. They need to validate schema and data consistency before switching traffic. Which THREE steps should they include in the migration plan?

Hard
132

An engineer is migrating a workload from a relational database to Bigtable. The current schema has a Customers table (1M rows) and an Orders table (100M rows) with a foreign key. Queries often fetch all orders for a customer. What is the best row key design for the Bigtable orders table?

Medium
133

A company wants to run complex analytical queries on terabytes of data with sub-second response times. The data is structured and stored in Cloud Storage as Parquet files. They need a serverless solution that can query the data directly without loading it into a database. Which service should they use?

Medium
134

You are running Cloud Bigtable for time-series analytics. Each row represents a metric and uses a row key of format 'metricID#timestamp' (e.g., 'cpu_usage#2023-08-01T00:00:00Z'). You notice that writes are concentrated on a small number of nodes. What is the most effective way to distribute writes more evenly?

Medium
135

A company wants to migrate their on-premises PostgreSQL database to Cloud SQL. The database currently runs mixed workloads: OLTP with heavy writes and occasional complex analytical queries. They want to avoid performance impact on the transactional workload. Which approach should they take?

Medium
136

You need to design a Bigtable row key for a time-series application that records temperature readings from thousands of sensors. The most common query is 'get all readings for a specific sensor in the last hour'. Which row key design is optimal?

Medium
137

You are designing a Spanner schema for a social media application. The table Posts has primary key (UserId, PostId) where PostId is a UUID. The application frequently queries all posts for a given user, ordered by timestamp descending. The current schema uses PostId as the second part of the key, which is random. How can you improve read performance for this query pattern?

Hard
138

A financial services company is migrating from an on-premises Oracle RAC database to Cloud Spanner. The current application uses sequences to generate globally unique IDs for transactions. To avoid creating hotspots in Spanner, the database architect recommends using a different primary key strategy. Which primary key design is most appropriate for Spanner to avoid hotspots?

Hard
139

An e-commerce platform uses Cloud Spanner with a table Orders and a child table OrderItems. The primary key of Orders is (CustomerId, OrderId) where OrderId is a UUID. The primary key of OrderItems is (CustomerId, OrderId, ItemId). However, writes to OrderItems are creating hotspots. What is the most likely cause?

Medium
140

A company is using Cloud SQL for PostgreSQL and wants to improve read scalability for a reporting dashboard that executes complex aggregate queries. The reports can tolerate up to 5 minutes of data staleness. Which two actions should the team take?

Medium
141

A data pipeline writes 10 TB of streaming data daily into Bigtable. The row key is based on the device ID and timestamp in reverse order. Recent data is queried most frequently. Which three design choices optimize performance and cost? (Choose THREE.)

Medium

Frequently asked questions

What does the Design innovative, scalable, and highly available cloud database solutions domain cover on the PCDE exam?
Cloud concepts questions usually test the service model (IaaS/PaaS/SaaS) and deployment model (public/private/hybrid/community) appropriate for a given scenario.
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This page lists all 141 Design innovative, scalable, and highly available cloud database solutions questions in the PCDE question bank. The actual exam draws from this domain proportionally to its weighting in the official exam blueprint.
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