Practice DBS-C01 Workload-Specific Database Design questions with full explanations on every answer.
Start practicing
Workload-Specific Database Design — choose a session length
Free · No account required
Click any question to see the full explanation and answer options, or start a focused practice session above.
A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The database has a large table that is frequently accessed by reporting queries. The reporting queries filter on a column that has a high cardinality but low selectivity. To optimize query performance on this table, which design choice should the database specialist recommend?
2A company is designing a new e-commerce platform using Amazon DynamoDB. The workload requires single-digit millisecond latency for user session data, which is accessed by session token. The session data is temporary and should be automatically deleted after 24 hours. Which DynamoDB design should the database specialist recommend?
3A financial services company is migrating its Oracle database to Amazon Aurora PostgreSQL. The database runs a critical batch processing job every night that updates millions of rows. The company needs the migration to minimize downtime and ensure data integrity. Which AWS service should the database specialist use to perform the migration?
4A social media application uses Amazon DynamoDB as its primary data store. The application stores user posts and allows users to retrieve the most recent 10 posts of users they follow. The access pattern is a followee-based query that needs to be highly scalable and low-latency. Which DynamoDB table design should the database specialist recommend?
5A company is running a MySQL database on Amazon RDS and needs to store JSON documents that are frequently queried by fields within the JSON. The company wants to reduce development complexity and improve query performance. Which RDS MySQL feature should the database specialist recommend?
6A company is designing a multi-tenant SaaS application on Amazon Aurora MySQL. Each tenant has its own database, but some tenants are very large and generate high write traffic. The company wants to isolate tenant workloads to prevent a noisy neighbor from affecting other tenants. Which TWO design strategies should the database specialist recommend?
7A company is running a critical application on Amazon DynamoDB. The table has a partition key of 'user_id' and a sort key of 'timestamp'. The application frequently queries for all items for a given user within a date range. The read capacity is often throttled during peak hours. Which THREE steps should the database specialist take to resolve the throttling?
8A database specialist is analyzing an Aurora MySQL error log and finds the above deadlock error. The application performs an update on the orders table and then updates the inventory table within the same transaction. The deadlock occurs when two concurrent transactions try to update orders and inventory in different orders. Which design change should the database specialist recommend to reduce deadlocks?
9A company is implementing fine-grained access control for a DynamoDB table named UserSessions. The table has a partition key of 'user_id'. The above IAM policy is attached to an IAM role assumed by the application. What does this policy achieve?
10A company is designing a multi-tenant SaaS application on Amazon RDS for PostgreSQL. Each tenant's data must be isolated for security and performance. The application has millions of tenants, with most tenants having small datasets (under 100 MB). Which database design pattern is MOST cost-effective and operationally efficient?
11A gaming company uses Amazon DynamoDB for player session data. Each session has a partition key of `game_id` and a sort key of `session_id`. The table has a global secondary index (GSI) on `player_id` for leaderboard queries. Recently, the company noticed that write traffic to the GSI is causing throttling on the base table, even though the base table's write capacity is not fully utilized. What is the MOST likely cause?
12A company is migrating a MySQL database to Amazon Aurora MySQL. The current database uses multi-statement transactions with read committed isolation level. The application frequently encounters deadlocks on the source database. Which Aurora MySQL feature can help reduce deadlocks without application changes?
13A social media startup is using Amazon ElastiCache for Redis to cache user profiles. The cache currently has a 24-hour TTL. The application experiences a sudden spike in traffic after a celebrity mentions the service, causing the cache to be flooded with requests for uncached profiles. This results in high latency and database load. Which design pattern should the company implement to prevent this in the future?
14A financial services company is designing a ledger system using Amazon QLDB. The application records transactions that must never be modified or deleted. The company expects high write throughput and needs to ensure that the ledger can handle the load without throttling. Which design consideration is MOST important to achieve this?
15A company is using Amazon DynamoDB for a shopping cart application. The table has a partition key of `user_id` and a sort key of `item_id`. The application performs frequent updates to the `quantity` attribute. The company notices that write requests are being throttled during peak hours. Which TWO actions would help reduce throttling? (Choose two.)
16A company is migrating an on-premises MongoDB database to Amazon DocumentDB. The database stores IoT sensor data with time-series characteristics. The application performs range queries on timestamp fields and updates recent documents frequently. Which THREE aspects of DocumentDB should the company consider to optimize performance for this workload? (Choose three.)
17A gaming company uses Amazon DynamoDB as the primary database for their player sessions. The player sessions table has a partition key of 'player_id' and a sort key of 'session_start_time'. The application frequently queries for recent sessions of a specific player, using the query API with 'player_id' and a filter on 'session_start_time' for the last 24 hours. The average item size is 5 KB. The company notices high latency on these queries during peak hours. The table has 10 Read Capacity Units (RCUs) provisioned. There are no indexes. Which design change would MOST improve query performance?
18A financial services company uses Amazon RDS for MySQL to store transaction data. The database has a single table 'transactions' with 500 million rows. The table has an auto-increment primary key and an index on 'transaction_date'. The company runs a monthly report that aggregates transactions by account_id and transaction_date. The report query uses a GROUP BY on account_id and transaction_date, and scans the entire table. The query takes over 2 hours to complete and often times out. The DBA suggests creating a materialized view. However, the company wants to minimize operational overhead. Which solution meets the requirements with the LEAST operational overhead?
19A company is designing a database for an e-commerce application that needs to store product catalog data. The data is highly structured with relationships between products, categories, and suppliers. The application requires ACID transactions to maintain data integrity when updating inventory. The company expects moderate read and write traffic. Which AWS database service is MOST suitable for this workload?
20A social media company uses Amazon DynamoDB to store user posts. The table has a partition key of 'user_id' and a sort key of 'post_timestamp'. Each item is about 10 KB. The application needs to retrieve all posts for a given user within a date range. The company recently added a new feature that allows users to 'like' posts, and they store the like count as an attribute in the post item. The like count is updated frequently. The application experiences high write throttling on the table. The table has 1000 WCUs provisioned. The write pattern is bursty. Which design change would MOST effectively reduce write throttling?
21A company is designing a database for an IoT application that ingests sensor data from thousands of devices. Each device sends a reading every minute. The data includes device_id, timestamp, temperature, humidity, and pressure. The application needs to store this data and support queries that retrieve all readings for a specific device within a time range. The company expects high write throughput and moderate read frequency. The data must be stored with high durability. Which TWO database designs are appropriate for this workload? (Choose TWO.)
22A company runs a customer relationship management (CRM) application on Amazon RDS for PostgreSQL. The application has a table 'customers' with columns: id (primary key), name, email, signup_date, and status. The table has 10 million rows. The application frequently queries by email address. The company also needs to run analytical queries that aggregate customers by signup_date and status. The DBA notices that the index on email is heavily used and causes high write latency. The company wants to improve write performance without sacrificing read performance for email queries. Which THREE actions should the database specialist take? (Choose THREE.)
23A company runs a multi-tenant SaaS application on Amazon DynamoDB. Each tenant's data is stored in a separate table named with a tenant-specific prefix (e.g., tenant1_orders, tenant2_orders). The application uses DynamoDB Streams to replicate data to a central analytics table. Recently, the company added a new large tenant that generates 10x more write traffic than any other tenant. The DynamoDB Streams for the large tenant's table is falling behind by several hours, causing stale data in the analytics table. The company has already increased the write capacity of the large tenant's table to 50,000 WCUs, but the streams lag persists. The analytics table is also in DynamoDB and uses a Global Secondary Index (GSI) for querying. The streams processing Lambda function performs simple transformations and writes to the analytics table. The Lambda function is not throttled. Which action would resolve the streams lag?
24A logistics company uses Amazon RDS for MySQL to track package shipments. The 'shipments' table contains 200 million rows and has a primary key on 'shipment_id' (UUID). The application frequently queries for shipments by 'tracking_number', which is a unique string of 20 characters. The DBA created a B-tree index on tracking_number. The queries by tracking_number are fast, but inserts are becoming slower over time. The table has 50 GB of data. The company plans to double the insert rate next month. The database is a db.r5.large instance with 500 GB of Provisioned IOPS SSD storage. The instance's CPU utilization is below 30%, and there is no lock contention. What should the database specialist do to improve insert performance?
25A social media analytics company uses Amazon DynamoDB as the primary data store for user session data. Each session record has a partition key of user_id (String) and a sort key of session_start_time (Number, epoch). The application often queries the most recent 10 sessions for a given user. The traffic pattern shows that 90% of reads are for the last 10 sessions, while 10% are for historical sessions. The table has a provisioned read capacity of 5000 RCU and consistently experiences throttled read requests during peak hours. The company wants to optimize read performance without changing the provisioned capacity. Which design change will MOST improve read performance for this workload?
26A gaming company uses Amazon RDS for PostgreSQL to store player profiles and game state data. The database is currently 500 GB and grows by 10 GB per day. The company runs weekly reports that scan the entire database, causing high I/O and CPU usage. The application experiences read latency spikes during report generation. The team wants to minimize performance impact on the application while maintaining the ability to run reports. Which solution should the team implement?
27A financial services company uses Amazon DynamoDB to store transaction records. Each transaction has a unique transaction_id as the partition key and a timestamp as the sort key. The application frequently queries all transactions for a given customer within a date range. However, customer_id is not an attribute indexed for querying. The company wants to optimize these queries without redesigning the entire table schema. Which action should the company take?
28Arrange the steps to migrate an on-premises Oracle database to Amazon RDS for Oracle using AWS DMS (Database Migration Service) in the correct order.
29Arrange the steps to enable encryption at rest for an existing unencrypted Amazon RDS for MariaDB DB instance in the correct order.
30Match each AWS service to its primary purpose.
31Match each RDS storage type to its description.
32A company runs a customer-facing application on Amazon RDS for MySQL. The application experiences frequent read replicas lagging behind the primary due to long-running analytics queries. The analytics team runs complex SELECT queries that scan large tables. Which design change would minimize replica lag without affecting production writes?
33A startup is building a real-time leaderboard for a mobile game using Amazon DynamoDB. The leaderboard must update frequently and support global access with low latency. Which database design approach is most suitable?
34A company needs to store and query time-series data from IoT sensors. The data is written continuously and queried by time range for dashboards. Which AWS database service is most cost-effective and scalable for this workload?
35A company uses Amazon DynamoDB for a shopping cart application. During a flash sale, write requests are throttled due to hot partitions. The access pattern is evenly distributed across items, but the partition key is the customer ID. Which design change would best mitigate throttling?
36A company is migrating an on-premises MongoDB database to AWS. Which AWS database service is most compatible and requires minimal application changes?
37A company needs to implement a database solution for a global e-commerce platform that requires strongly consistent reads and writes with automatic failover across AWS Regions. Which service should be used?
38A company runs a critical OLTP workload on Amazon RDS for PostgreSQL. The database size is 2 TB and growing. To reduce storage costs, the company wants to archive old data that is rarely accessed. Which approach is most cost-effective and minimally impacts performance?
39A company runs an application that requires a relational database with high availability across multiple Availability Zones. The database must automatically failover with minimal downtime. Which AWS service meets these requirements?
40A company uses Amazon DynamoDB for a session management workload. The access pattern is random and requires single-digit millisecond latency. The table has a read capacity of 5000 RCU. During peak hours, read requests occasionally exceed this capacity, causing throttling. Which design change is most appropriate to handle traffic spikes?
41A company is designing a document database on Amazon DocumentDB for a content management system. Which TWO design practices improve query performance and reduce costs?
42A company needs to choose a database for a real-time analytics workload that requires sub-second query latency on streaming data. Which TWO AWS services are most suitable?
43A company is migrating a large Oracle data warehouse to Amazon Redshift. Which THREE design considerations are important for performance optimization?
44A company is designing a database for a global e-commerce application with millions of users. The workload requires single-digit millisecond read latency, high availability across multiple AWS Regions, and strong consistency. Which database service should the company use?
45A media company is storing large video files (up to 10 GB each) in Amazon S3 and needs to maintain metadata about each file, including title, duration, and upload timestamp. The workload involves frequent writes (1000+ per second) and occasional read queries by title. Which database is best suited for this metadata store?
46A company runs a time-series application that collects sensor data from millions of IoT devices. The data is written in batches every minute and queried to generate hourly, daily, and monthly aggregates. The database must support high ingestion rates and efficient storage. Which database service is most appropriate?
47A financial services company is migrating an on-premises Oracle database to AWS. The database supports an OLTP application with complex joins, stored procedures, and requires high availability within a single Region. The company wants to minimize licensing costs and use a fully managed service. Which AWS database service should they choose?
48A company is building a social network application that needs to store user profiles, friend relationships, and a feed of posts. The feed queries are complex, involving graph traversals (e.g., friends of friends). Which database is best suited for the relationship data?
49A company needs to store and query JSON documents that vary in structure. The application requires flexible schema, automatic indexing, and the ability to run complex aggregation pipelines. Which AWS database service should be used?
50A company runs an analytics platform that queries billions of rows of sales data. Queries are complex and involve aggregations across multiple dimensions. The data is updated in bulk daily. Which service should be used as the primary data store?
51A gaming company needs a database to store player session data that is ephemeral and requires sub-millisecond latency. The data can be lost on failure without impact. Which service is best?
52A company is designing a database for a mobile application that requires offline synchronization. Users should be able to read and write data while offline, and changes should sync when connectivity is restored. Which AWS service supports this pattern?
53Which TWO database services are most suitable for workloads that require ACID transactions?
54Which THREE factors should be considered when designing a database for a high-traffic web application that requires low-latency reads and writes?
55Which TWO AWS services can be used to implement a serverless database architecture for variable workloads?
56A company is designing a database for an e-commerce platform that requires high availability and automatic failover with minimal downtime. The application performs both OLTP and read-heavy analytics. Which AWS database service should be used?
57A startup is building a real-time leaderboard for a gaming application. The data is highly dynamic with frequent updates and requires single-digit millisecond latency. Which database is most suitable?
58A company needs to migrate an on-premises Oracle database to AWS with minimal changes to the application code. The application uses complex stored procedures and has high availability requirements. Which database service should be used?
59A company is building a document management system where each document can have multiple attributes (tags) that need to be queried efficiently. The workload is write-heavy with occasional reads. Which database is best suited?
60A company is designing a multi-region active-active application that requires low-latency reads and writes across regions. The database must support conflict resolution. Which database should be used?
61A company needs to store and query time-series data from IoT devices. The data arrives in high volume and requires efficient range queries over time. Which database is most appropriate?
62A company is running a MongoDB workload on-premises and wants to migrate to AWS with minimal operational overhead. The application uses MongoDB-specific features like aggregation pipelines. Which service is best?
63A company needs to build a reporting dashboard that queries a large dataset stored in Amazon S3. The queries are complex and require full SQL support. Which service should be used?
64A company is designing a social media application that requires storing user relationships (follows) and making graph queries like 'mutual friends.' Which database is most suitable?
65Which TWO of the following are best practices for designing a DynamoDB table for high traffic? (Choose 2)
66Which THREE factors should be considered when choosing between Amazon RDS Multi-AZ and Amazon Aurora for high availability? (Choose 3)
67Which TWO are valid use cases for Amazon ElastiCache for Redis? (Choose 2)
68A database administrator runs the above command. The database is currently in a healthy state. Which statement is true about this database?
69An IAM policy is attached to a user to restrict access to a DynamoDB table. What does this policy allow the user to do?
70A developer sees the above key schema for the ProductCatalog table. Which query will be most efficient for retrieving a single item?
71A company is designing a database for a real-time bidding system that requires sub-millisecond read and write latency for ad impressions. The workload is heavily write-intensive with occasional reads by campaign IDs. Which AWS database service is most suitable?
72A gaming company uses Amazon RDS for PostgreSQL to store player profiles and game state. They report slow queries during peak hours. The DB instance is a db.r5.2xlarge with 500 GB gp2 storage. Which design change would MOST improve read performance for the most frequently accessed player profiles?
73A financial services company needs a relational database with high availability and automatic failover across three Availability Zones in us-east-1. The workload consists of OLTP transactions with occasional analytic queries. Which database solution meets these requirements?
74A company is migrating an on-premises MongoDB database to AWS. The database stores JSON documents for a content management system. The workload requires read-after-write consistency and automatic scaling. Which AWS database service is MOST appropriate?
75A company runs a global e-commerce platform with a relational database. They need to reduce read latency for users in Europe and Asia. The primary database is in us-west-2. Which solution provides the LOWEST read latency for global users while maintaining data consistency?
76A startup is building a mobile application that requires a database to store user preferences and session data. The data is accessed by user ID and requires single-digit millisecond latency. The workload is read-heavy with occasional writes. Which database service is MOST cost-effective?
77A company uses Amazon RDS for Oracle for an OLTP application. The database experiences high CPU utilization during peak hours. The application is read-heavy and can tolerate eventually consistent reads. Which solution reduces CPU load on the primary database with minimal application changes?
78A company is designing a database for an IoT application that ingests millions of sensor readings per second. Each reading includes device ID, timestamp, and measurement. The workload requires time-series analytics and data retention for 90 days. Which AWS database solution is MOST appropriate?
79A company needs a fully managed graph database for a social networking application that requires real-time recommendations based on friend connections. Which AWS service should they use?
80A company is designing a disaster recovery strategy for an Amazon RDS for PostgreSQL database. They need a Recovery Point Objective (RPO) of less than 5 seconds and a Recovery Time Objective (RTO) of less than 1 minute. Which TWO actions should they take? (Choose two.)
81A company is migrating a large Oracle data warehouse to AWS. The warehouse contains 50 TB of data and runs complex analytical queries. The solution must support concurrency of up to 100 users and provide high performance for queries. Which THREE design decisions should the company make? (Choose three.)
82A company is building a microservices architecture and needs a database for a service that stores JSON documents with variable schema. The database must support high availability and automatic scaling. Which TWO services meet these requirements? (Choose two.)
83Refer to the exhibit. An IAM policy is attached to an IAM role used by a Lambda function that writes to a DynamoDB table. The function also needs to read items from the table. What is the outcome of this policy?
84Refer to the exhibit. A developer reports that the RDS MySQL instance 'mydb' is experiencing high write latency. The storage is gp2 with 100 GB. What is the MOST likely cause of the write latency?
85Refer to the exhibit. A developer created a DynamoDB table 'UserSessions' with a simple primary key. The application needs to query by user_id as well. What design change should the developer make to support this query efficiently?
86A company is migrating an on-premises MySQL database to Amazon RDS. The database is used for a critical e-commerce application that requires high availability with automatic failover. Which RDS deployment option should the company choose to meet these requirements?
87A company is designing a database for a social media application that requires low-latency access to user profiles and support for complex graph queries. Which AWS database service is most suitable for this workload?
88A company is running a production Amazon RDS for PostgreSQL database. The database experiences high write latency during peak hours. The company wants to reduce latency without changing the application code. Which solution is MOST cost-effective and scalable?
89A company is designing a database for an IoT application that ingests millions of time-series data points per second. The database must support high-throughput writes and efficient querying of recent data. Which AWS database service is MOST suitable?
90A company is building a mobile application that requires users to be able to query their order history quickly. The data is stored in Amazon DynamoDB, and each user has up to 10,000 orders over time. The application needs to support pagination and filtering by order date. What is the MOST efficient way to model this data in DynamoDB?
91A company is running a production Amazon DynamoDB table that supports a gaming application with millions of concurrent users. The table uses on-demand capacity mode. Recently, the application started experiencing throttling (ProvisionedThroughputExceededException) during peak hours. The company wants to resolve this with minimal operational overhead. What should the company do?
92A company is using Amazon DynamoDB to store session data for a web application. The session data expires after 24 hours. Which DynamoDB feature should the company use to automatically delete expired items?
93A company is migrating an on-premises Oracle database to Amazon Aurora PostgreSQL. The database is used for a financial application that requires complex joins and transactions. Which migration strategy is MOST appropriate?
94A company is running a production Amazon RDS for MySQL database that is experiencing performance degradation. Amazon CloudWatch metrics show high CPU utilization and high number of connections. The company has already optimized queries and implemented connection pooling. What is the MOST cost-effective solution to address the high CPU utilization?
95Which TWO of the following are benefits of using Amazon DynamoDB Accelerator (DAX)? (Choose 2.)
96Which THREE of the following are best practices for designing a DynamoDB table for a gaming leaderboard that updates scores frequently and supports queries for top players? (Choose 3.)
97Which TWO use cases are best suited for Amazon RDS Multi-AZ deployments? (Choose 2.)
98The application uses the IAM role to access the 'orders' DynamoDB table. What is the intended effect of this policy?
99Based on the CLI output, what is true about this RDS instance?
100What is the purpose of the 'TimeToLiveSpecification' in this template?
101A financial services company is migrating an on-premises Oracle database to Amazon RDS for Oracle. The database has a high volume of write transactions and requires minimal downtime during migration. Which AWS service or feature should be used to replicate data continuously to the target RDS instance during the migration?
102A gaming company runs a leaderboard application on Amazon DynamoDB. The application experiences sudden spikes in read traffic during tournaments. The table uses on-demand capacity and the reads are eventually consistent. However, some users report stale data for several seconds. What is the most likely cause?
103A healthcare company stores patient records in Amazon DynamoDB. Each record includes a 'patient_id' (partition key) and 'visit_date' (sort key). The company needs to run ad-hoc queries to find all patients seen by a specific doctor within a date range. Which design approach minimizes cost and latency for this query pattern?
104A company is designing a database for an IoT application that collects sensor data every second from millions of devices. The data is time-series and must be stored for 90 days, with occasional queries for recent data. Which AWS database solution is MOST cost-effective and performant?
105A company is using Amazon RDS for PostgreSQL for its transactional database. The application generates reports that query millions of rows, causing high CPU on the primary instance. The reports are not time-sensitive. What is the MOST cost-effective way to offload the reporting queries without affecting write performance?
106A company is deploying a globally distributed application with users in the US, Europe, and Asia. The application requires sub-10ms read latency for user profiles stored in Amazon DynamoDB. Writes are less frequent. Which configuration meets the latency requirement while minimizing write conflicts?
107A company is migrating a 5 TB Microsoft SQL Server database to Amazon RDS for SQL Server. The database has many stored procedures and triggers. The migration must have minimal downtime. Which approach should be used?
108A startup is building a mobile app that requires a scalable NoSQL database. The data model includes user profiles with variable attributes that change over time. The database must support high read throughput and low latency. Which AWS database is best suited?
109A company uses Amazon RDS for MySQL with a Multi-AZ deployment. During a recent failover, the application experienced a 2-minute downtime because it was connecting to the primary instance endpoint. The company needs to reduce failover downtime to under 30 seconds. What should be done?
110Which TWO factors should be considered when choosing between Amazon DynamoDB and Amazon RDS for MySQL for a new e-commerce application with variable traffic patterns?
111Which THREE design patterns can improve the performance of a write-heavy application using Amazon DynamoDB?
112Which TWO Amazon RDS features can be used to increase the availability of a production database?
113An IAM policy is attached to a user to allow read access to the Orders table in DynamoDB. The user reports that a GetItem call for an order returns an 'AccessDeniedException'. What is the likely cause?
114A developer is trying to create a FULLTEXT index on a column in an RDS MySQL instance. The error log shows the index creation failed. What is the most likely cause?
115A company is deploying an RDS MySQL database using the above CloudFormation template. After deployment, the database automatically reboots during the maintenance window. The company wants to reduce the impact of maintenance events. Which parameter change would minimize unavailability?
116A company is migrating an on-premises MySQL database to Amazon RDS for MySQL. The database has a large table with frequent inserts and updates. To minimize downtime during migration, which AWS service should be used?
117A gaming company uses Amazon DynamoDB with global tables across two regions. They notice increased write latency and throttling during peak hours. The access pattern is mostly writes to a small set of hot partitions. Which design change would best address this?
118A company needs to store JSON documents that are frequently accessed by a web application. The documents have varying attributes and the query pattern includes filtering on multiple fields. Which AWS database service is most suitable?
119A company is building a real-time analytics dashboard from IoT sensor data. Data arrives as time-series with millions of writes per second. The dashboard queries the last hour of data with aggregations. Which database design is most cost-effective?
120A company uses Amazon RDS for PostgreSQL for its e-commerce platform. The application team reports increasing read latency on the primary instance during sales events. Which action should be taken to reduce read load on the primary?
121A company is designing a database for a social media application that needs to handle friend-of-friend queries and recommendation engine traversals. Which AWS database is best suited?
122A startup needs a fully managed relational database with automated backups and scaling. They expect unpredictable workloads. Which AWS service meets these requirements?
123A company uses Amazon DynamoDB for a session management system. They need to store session data with a TTL of 24 hours. However, they notice that expired items are not being deleted promptly, causing storage costs to increase. What is the most likely cause?
124A company wants to run a MongoDB-compatible database on AWS with automated patching and backups. Which service should they choose?
125Which TWO design patterns are commonly used to handle hot partitions in Amazon DynamoDB? (Choose 2.)
126Which THREE factors should be considered when choosing between Amazon RDS and Amazon DynamoDB for a new application? (Choose 3.)
127Which TWO techniques can reduce read latency for frequently accessed data in Amazon DynamoDB? (Choose 2.)
128A company is migrating an on-premises MongoDB workload to Amazon DocumentDB. The current workload uses secondary indexes heavily for reporting queries. Which design consideration should the company evaluate to ensure optimal performance on DocumentDB?
129A financial services company runs an Amazon Aurora MySQL database. The application performs complex joins and aggregations on large tables, causing high CPU utilization on the writer instance. The team wants to reduce load without changing the application code. Which solution would best address this issue?
130A gaming company uses Amazon DynamoDB as the database for user profiles and game state. The application requires strongly consistent reads for the user's own profile, but eventually consistent reads for leaderboard queries. How should the company design the table and queries?
131A media company uses Amazon ElastiCache for Redis to cache database query results and reduce load on the primary database. The cache hit ratio is low because the cache is purged frequently. The team wants to improve the hit ratio without increasing the cache size. Which strategy should they implement?
132A company is designing a global e-commerce application that requires a relational database with sub-10ms read latency across multiple AWS Regions. The database will store inventory and product catalog data. Which database design should they choose?
133A healthcare application stores patient records in Amazon DynamoDB. Each record has a unique patient ID and contains sensitive health information. The application must encrypt data at rest and ensure that only authorized services can access the data. Which combination of design choices meets these requirements?
134A startup is building a social media application that requires a database to store user relationships (followers, following) and support graph queries. The data volume is expected to grow to tens of terabytes. Which AWS database service is most suitable for this workload?
135A company uses Amazon RDS for PostgreSQL to run a reporting application. The reporting queries are complex and take several minutes to complete, causing performance impact on the primary instance. The company wants to isolate the reporting workload without data staleness. Which solution should they implement?
136A company is designing a disaster recovery plan for an Amazon DynamoDB table that stores critical session data. The table is provisioned with on-demand capacity. The recovery objective is to have the data available in another AWS Region within 15 minutes of a regional outage. Which design should they choose?
137A company is designing an Amazon RDS for MySQL database for an e-commerce application. Which TWO design strategies will help ensure high availability and automatic failover in the event of a primary instance failure?
138A company is using Amazon DynamoDB to store IoT sensor data. The application writes a large volume of data and needs to read recent data by timestamp. The table has a partition key of device_id and a sort key of timestamp. The access pattern is to read the latest data for a specific device. Which TWO design patterns will optimize read performance and reduce costs?
139A company is designing a document database on Amazon DocumentDB. The workload requires high write throughput and needs to support complex queries on nested attributes. Which THREE design considerations should the company evaluate to meet these requirements?
140A company is running an Oracle database on Amazon RDS with the configuration shown in the exhibit. The application is experiencing high latency for write operations. The storage is consistently showing high queue depth and write latency. Which change will most improve write performance?
141A company uses the IAM policy shown in the exhibit to control access to a DynamoDB table. The table has a partition key user_id and a sort key timestamp. The application uses the AWS SDK to query items. When a user tries to query items with a filter condition, they receive an AccessDeniedException. What is the most likely cause?
142A company's application is logging the error shown in the exhibit. The application is deployed on Amazon EC2 and connects to an Amazon RDS for MySQL Multi-AZ DB instance. Which configuration change is most likely to resolve this issue?
143A company is designing a new application that requires a relational database with sub-millisecond read latency for a global user base. The workload is read-heavy with occasional writes. Which database solution should they choose?
144A social media application stores user posts in an Amazon RDS for PostgreSQL instance. The application experiences a sudden spike in read traffic during peak hours, causing database bottlenecks. The team needs to improve read scalability without changing the application code. Which solution is MOST cost-effective?
145A company runs a time-series application that records sensor data every second. The data volume is 500 GB per month and grows continuously. They need to query the last 30 days of data frequently and older data rarely. Which database design is MOST appropriate?
146A financial services company uses Amazon Aurora MySQL-Compatible Edition for transaction processing. They need to run complex analytical queries on the same data without impacting transactional performance. Which solution meets these requirements?
147An e-commerce application uses Amazon DynamoDB as its primary database. The table stores order data with a partition key of 'OrderID' and a sort key of 'OrderDate'. The application frequently queries orders by customer ID (which is not a key attribute). What design change would improve query performance?
148A startup needs a cost-effective database for a small application that handles both transactional and analytical workloads. They expect low traffic initially but want the database to automatically scale as the business grows. Which database solution is BEST suited?
149A company runs a document management system using Amazon DocumentDB (with MongoDB compatibility). The application stores large documents (up to 5 MB each) and frequently fetches them by document ID. The team notices increased latency during peak hours. They need to reduce read latency. Which action is MOST effective?
150A mobile gaming application uses Amazon DynamoDB to store player profiles and game state. The write throughput is high during events, but low otherwise. The company wants to minimize costs while maintaining performance. Which capacity mode should they use?
151A company is migrating an on-premises Oracle data warehouse to AWS. The warehouse contains 20 TB of data and supports complex SQL queries with joins and aggregations. The migration should minimize downtime and require minimal changes to existing SQL queries. Which database service is MOST appropriate?
152Which TWO are valid considerations when designing a global database with Amazon Aurora Global Database? (Select TWO.)
153Which TWO are best practices for designing a DynamoDB table for high-traffic e-commerce application? (Select TWO.)
154Which THREE are factors to consider when choosing between Amazon RDS and Amazon DynamoDB? (Select THREE.)
155Refer to the exhibit. An application team notices that the MySQL RDS instance 'mydb' is running at 80% CPU utilization during peak hours. They need to improve read performance without increasing the CPU load on the primary instance. Which action should they take?
156Refer to the exhibit. An IAM policy is attached to a role used by an application that accesses the DynamoDB 'Orders' table. The application needs to perform a Scan operation on the table. According to the policy, is the Scan operation allowed?
157Refer to the exhibit. A CloudFormation template creates a DynamoDB table. The application team needs to query orders by customer ID (which is not a key attribute). Which change to the template would enable efficient querying by customer ID?
158A company is designing a database for an e-commerce application that requires high availability and automatic failover. The application performs mainly read-heavy workloads with occasional write spikes during flash sales. Which AWS database service is most suitable for this workload?
159A social media startup stores user posts in Amazon DynamoDB with a partition key of user_id and sort key of post_timestamp. The application frequently queries the five most recent posts for a given user. Which design pattern improves query performance and reduces cost?
160A company runs a time-series application on Amazon RDS for PostgreSQL. The table 'events' has 500 million rows and is queried by event_time and event_type. Queries for the last hour are slow despite indexing. Which design change would most improve query performance?
161A company needs to store session data for millions of users with sub-millisecond latency. The data is key-value in nature and can tolerate eventual consistency. Which database service is best suited?
162A financial services company runs a critical application on Amazon RDS for Oracle. The workload is write-heavy with frequent small transactions. The DBA notices high latency during peak hours. Which design change would best address this?
163A gaming company uses Amazon DynamoDB to store player profiles with partition key player_id. The access pattern is to retrieve profiles for multiple players in a single request. The application currently makes separate GetItem calls, causing high latency. Which design pattern reduces latency and cost?
164A startup needs a fully managed, serverless database for a new web application with unpredictable traffic. The application requires ACID transactions and SQL queries. Which AWS database service should they use?
165An IoT company ingests sensor data into Amazon DynamoDB. The data has a partition key of device_id and sort key of timestamp. Queries often filter by device_id and a date range. Which design pattern improves query performance and reduces cost?
166A company runs a data warehouse on Amazon Redshift. The workload has frequent DELETE and UPDATE operations on a large fact table. Over time, query performance degrades. Which maintenance operation should be scheduled regularly to optimize performance?
167Which TWO of the following are valid design considerations when using Amazon DynamoDB for a high-traffic e-commerce application? (Select TWO.)
168Which TWO of the following are recommended best practices for designing a relational database on Amazon RDS? (Select TWO.)
169Which THREE of the following are key considerations when designing a time-series database using Amazon DynamoDB? (Select THREE.)
170A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The database currently uses a custom extension that is not supported by RDS. The application relies heavily on this extension for advanced statistical analysis. Which design approach should the company take to minimize application changes?
171A startup is building a social media analytics application that ingests high-velocity streaming data from multiple sources. The data consists of JSON objects with varying schemas. The application needs to store this data for real-time querying and later batch processing. Which AWS database solution is most cost-effective and scalable for this workload?
172A company is designing a multi-tenant SaaS application using Amazon Aurora PostgreSQL. Each tenant's data must be isolated for security and compliance. The application has a few large tenants and many small tenants. Queries must be able to access data across tenants for reporting, but with strict access controls. Which design best meets these requirements?
173A gaming company uses Amazon DynamoDB to store player profiles and game state. The access patterns include: (1) lookup by player ID, (2) query by game ID for recent games, and (3) leaderboard queries sorted by score. The current single-table design is causing hot partitions on the leaderboard queries. What design change should the company implement to resolve hot partitions?
174A company is designing a document management system using Amazon S3 and needs to store metadata such as document ID, owner, creation date, and tags. The metadata must be searchable with low latency, supporting queries like 'Find all documents owned by user X with tag Y created after date Z'. Which AWS database service is most suitable for storing and querying this metadata?
175A financial services company runs a critical application on Amazon RDS for MySQL. The database stores transaction data that must be retained for 7 years for regulatory compliance. The current retention policy stores all data in the same table, causing performance degradation on the main transactional table. The company needs to archive data older than 1 year while keeping it queryable. Which design should they implement?
176A company is building a real-time chat application using Amazon DynamoDB. Each message has a conversation ID, timestamp, sender, and content. The primary access pattern is to retrieve the most recent 50 messages for a given conversation, ordered by timestamp. Which table design minimizes cost and latency?
177A company is migrating an on-premises MongoDB database to AWS. The application uses MongoDB's aggregation pipeline for real-time analytics. Which AWS database service is most compatible and provides the least application changes?
178A company uses Amazon RDS for Oracle with a custom application that generates complex hierarchical queries using CONNECT BY. They want to migrate to Amazon Aurora to reduce licensing costs. Which migration strategy requires the fewest application changes?
179A company is designing a global e-commerce platform using Amazon DynamoDB. The platform must support strong consistency for inventory updates and eventual consistency for product catalog reads. Which TWO design patterns should the company implement to meet these consistency requirements?
180A company is designing a data lake on Amazon S3 with Amazon Redshift Spectrum for analytics. The data includes JSON logs from web servers. Which THREE design practices should the company follow to optimize query performance and cost?
181A company uses Amazon RDS for PostgreSQL for its CRM application. The application experiences intermittent spikes in read traffic. Which TWO actions can the company take to improve read scalability with minimal application changes?
182A database administrator is troubleshooting a slow-performing query on an Amazon RDS for MySQL instance. The slow query log shows the above entry. Based on the exhibit, which index would most improve the query performance?
183A security engineer created the IAM policy above for an application that reads from a DynamoDB table named UserSessions. The application reports that it cannot query the table using a Global Secondary Index (GSI). The table's GSI is named GSI_UserSessions. Why is the application unable to query the index?
184A company is running an Amazon RDS for MySQL instance as shown in the exhibit. The application is experiencing high write latency. The instance has a high number of write operations and the storage queue depth is consistently above 100. Which change would most effectively reduce write latency?
185A company runs an e-commerce platform on Amazon RDS for PostgreSQL. During a flash sale, the database experiences high write load and read replicas lag significantly. The application uses read replicas for reporting queries. Which design change would most effectively reduce replica lag without compromising write performance?
186A company uses Amazon DynamoDB as the primary database for a global gaming application. The application requires single-digit millisecond latency for user profile lookups by user ID. However, some queries need to retrieve all active users in a region (e.g., 'us-east-1') for administrative dashboards, and these queries currently perform full table scans, causing high costs and throttling. What design approach should be taken to optimize this?
187A company is migrating a MySQL database from on-premises to Amazon RDS for MySQL. The current database has several stored procedures and triggers that use user-defined functions (UDFs) compiled as shared libraries. What is the best practice for handling these UDFs in RDS?
188A company has a document database workload on Amazon DynamoDB that stores user session data. The application frequently updates session attributes (e.g., last activity timestamp). The current design stores the entire session as a single item and updates the entire item on each session activity. This is causing high write costs and throttling. Which design pattern would reduce write costs and improve performance?
189A company is designing a multi-tenant SaaS application on Amazon RDS for PostgreSQL. Tenants have vastly different data sizes and access patterns. The current design uses a separate schema per tenant, but some tenants experience slow queries while others are fine. Which approach would best isolate tenant performance and simplify management?
190A company is using Amazon ElastiCache for Redis as a caching layer for frequently accessed data. The application needs to support caching of session data that must be highly available across multiple Availability Zones. Which ElastiCache configuration should be used?
191A company uses Amazon DynamoDB for a time-series IoT workload. Each device sends a data point every minute. The primary key consists of device_id (partition key) and timestamp (sort key). The company wants to efficiently retrieve the latest 10 data points for a specific device. Which query design is most efficient?
192A company is using Amazon RDS for Oracle with a very large database (10 TB). They need to migrate to Amazon Aurora PostgreSQL with minimal downtime. The source database is heavily used with constant writes. Which migration strategy is most appropriate?
193A company is migrating an on-premises MongoDB database to Amazon DocumentDB (with MongoDB compatibility). The application uses MongoDB's aggregation pipeline with $lookup and $unwind stages. What should the company verify before migration?
194A company is designing a database solution for a global user base that requires single-digit millisecond read latency for user profile data. The data is eventually consistent and can tolerate a few seconds of staleness. Which TWO AWS services or features should be combined to achieve this latency?
195A company is migrating a legacy Oracle data warehouse to Amazon Redshift. The source uses complex stored procedures with cursors, temporary tables, and PL/SQL. Which THREE design considerations should the company evaluate?
196A company runs a MySQL database on Amazon RDS for a financial application that requires point-in-time recovery (PITR) with a recovery window of at least 35 days. The database is 500 GB in size. Which TWO actions should be taken to meet these requirements?
197A company is using Amazon DynamoDB for a gaming leaderboard that updates frequently. They need to maintain a sorted list of top 100 players by score. Which THREE design patterns can achieve this efficiently?
198A company runs a large-scale e-commerce platform using Amazon RDS for MySQL with a Multi-AZ deployment. The database has a table 'orders' with 200 million rows. Recently, they added a new index on the 'order_date' column to improve reporting queries. After adding the index, they noticed increased write latency and occasional replication lag. The application writes new orders continuously. The table experiences about 10,000 writes per second. The DB instance is db.r5.4xlarge. The index creation was done using the ALTER TABLE statement with a default algorithm. What is the most likely cause of the increased write latency and replication lag?
199A company uses Amazon DynamoDB for a real-time analytics platform. The table has a partition key of 'customer_id' and a sort key of 'event_timestamp'. The table receives 50,000 write requests per second, evenly distributed across 10,000 customers. The application frequently queries the last 10 events for a given customer. The company notices that some queries are throttled during peak hours. The table's write capacity is set to 50,000 WCUs, and read capacity to 10,000 RCUs. The throttled queries are read requests. What is the most likely cause of the throttling, and what should be done to resolve it?
200A company is running a MySQL database on an EC2 instance and wants to migrate to Amazon RDS for MySQL with minimal downtime. The database is 500 GB in size and has a high write workload. Which migration approach is most appropriate?
201A company uses Amazon DynamoDB for a gaming leaderboard. The application updates scores frequently. Reads must be strongly consistent, and writes must be optimized for cost. Which table design minimizes cost while meeting consistency requirements?
202A company needs to store application logs for 90 days and run periodic analytical queries. The logs are generated at 1 TB per day. Which storage solution is most cost-effective?
203A company is designing a database for a global e-commerce platform that requires sub-millisecond read latencies from multiple AWS regions. The data is mostly read, with occasional writes. Which database solution meets these requirements?
204A company runs a MongoDB workload on Amazon EC2 and wants to migrate to Amazon DocumentDB. The database has a total size of 2 TB and experiences 10,000 writes per second during peak. Which migration strategy minimizes downtime?
205A company needs a database for a serverless web application that stores user sessions. The sessions expire after 24 hours. The database must be highly available and require no server management. Which AWS service is most appropriate?
206A company is migrating an on-premises Oracle database to Amazon Aurora PostgreSQL. The database is 1 TB and has complex stored procedures. The migration must be completed within a 4-hour downtime window. Which migration approach is most efficient?
207A company runs a financial application on Amazon RDS for PostgreSQL that requires point-in-time recovery (PITR) with a recovery point objective (RPO) of 1 second and recovery time objective (RTO) of 5 minutes. Which configuration meets these requirements at the lowest cost?
208A company uses Amazon DynamoDB for a time-series IoT application. Each device sends a data point every second. The application queries data by device ID and timestamp range. Which table design is most efficient?
209A company is designing a database for an analytics workload that requires storing 5 TB of data and running complex SQL queries with joins. The workload is read-heavy and requires high concurrency. Which TWO services are suitable for this workload? (Choose two.)
210A company is migrating a 2 TB Oracle database to Amazon Aurora MySQL. The database has custom PL/SQL packages and triggers. The migration must be completed with minimal application changes. Which THREE steps should the company take? (Choose three.)
211A company runs a PostgreSQL database on Amazon RDS for a CRM application. The database is 500 GB and experiences high read traffic. The company wants to improve read scalability and reduce latency. Which TWO actions should the company take? (Choose two.)
212A company runs a critical e-commerce platform on Amazon Aurora MySQL. The database is 2 TB and experiences a sudden spike in write latency during flash sales. The application uses auto-generated UUIDs as primary keys. The CPU utilization on the writer instance is 80%, and the read replicas show low utilization. Write latency has increased from 5 ms to 200 ms. The company needs to reduce write latency with minimal application changes. Which course of action is MOST effective?
213A company is building a real-time chat application that requires storing messages with a maximum of 10,000 characters per message. The application needs sub-millisecond latency for reads and writes. The data must be durable and replicated across three Availability Zones. The development team wants to minimize operational overhead. Which AWS database service is most appropriate?
214A company uses Amazon RDS for SQL Server with a 4 TB database for a financial reporting application. The database performs nightly batch updates that take 6 hours. The company needs to reduce the batch update time to under 2 hours. The current instance is db.r5.8xlarge with 64 vCPUs and 512 GB memory. The batch process is I/O-bound with high write throughput. Which change will MOST effectively reduce the batch update time?
215A company is running a MySQL database on Amazon RDS for a web application. The application experiences read-heavy traffic, and the company wants to improve read performance without changing the application code. Which design should the database specialist recommend?
216A company is designing a database for a global e-commerce platform that requires low-latency reads and writes across multiple AWS Regions. The database must support strongly consistent reads and provide automatic failover. Which AWS service should the company use?
217A company is migrating a PostgreSQL database to Amazon Aurora PostgreSQL. The current database has complex queries that join multiple tables and performs well. After migration, the same queries are slower on Aurora. What is the most likely cause?
218A company uses Amazon DynamoDB for a gaming application that stores player data. The application frequently accesses items by the player's user ID. However, the company also needs to query players by their subscription tier (Gold, Silver, Bronze) and registration date. Which design should the database specialist recommend for this access pattern?
219A company is running a MongoDB-compatible database on Amazon DocumentDB. The application performs frequent updates to a small subset of fields in documents. The company notices that write latency is high. What should the database specialist recommend to reduce write latency?
220A company has a critical application that uses Amazon RDS for MySQL with Multi-AZ deployment. During a recent failure, the automatic failover took 2 minutes, causing application timeout. The company needs to reduce failover time to under 30 seconds. Which solution should the database specialist recommend?
221A company is designing a database for an IoT application that ingests millions of small sensor readings per second. The data is time-series and queries are mostly range scans over time. The company needs a cost-effective solution with high write throughput. Which AWS service should the database specialist recommend?
222A company is designing a database for an e-commerce platform that needs to store product catalog data. The data is highly relational with many-to-many relationships between products, categories, and suppliers. The platform requires ACID transactions and complex joins. Which TWO AWS database solutions are suitable for this workload? (Choose TWO.)
223A company is moving a legacy on-premises Oracle database to AWS. The database has large tables with complex stored procedures and triggers. The company wants to minimize application changes. Which THREE AWS database services should the database specialist consider? (Choose THREE.)
224A company is designing a database for a social media application that requires storing user profiles, posts, and follower relationships. The application needs low-latency queries for user timelines and social graph traversals. Which TWO AWS database services should the database specialist consider? (Choose TWO.)
225Refer to the exhibit. A company uses this DynamoDB table to store user session data. The application frequently queries by user_id alone to get all sessions for a user. However, the query is slow. What is the most likely cause?
226Refer to the exhibit. A database specialist is troubleshooting an issue where an application cannot connect to an RDS for MySQL instance using IAM database authentication. The application uses the database user 'db_user1'. The IAM policy shown is attached to the IAM role used by the application. What is the most likely reason for the connection failure?
227A company runs a financial analytics platform on Amazon DynamoDB. The table stores transaction records with a partition key of account_id and a sort key of transaction_timestamp. Each account has thousands of transactions. The application frequently queries the most recent transactions for a given account_id, sorted by timestamp in descending order. Recently, as the number of accounts grew, the query latency increased significantly. The DynamoDB table has provisioned read capacity of 10,000 RCUs, and CloudWatch metrics show that consumed read capacity is at 60%. The database specialist suspects that the issue is due to the query pattern. Which action should the database specialist take to reduce query latency?
228A company runs a customer relationship management (CRM) application on Amazon RDS for PostgreSQL. The application stores customer data in a table with over 50 million rows. The company recently added a new query that searches for customers by their email domain (e.g., '@example.com'). The query uses a LIKE pattern: 'WHERE email LIKE ''%@example.com'''. The query takes over 30 seconds to complete. The DBA has already created a B-tree index on the email column, but it does not help. Which action should the database specialist recommend to improve query performance?
229A company is designing a database for a ride-sharing application that needs to store real-time driver locations and trip history. The application requires low-latency updates to driver locations (every few seconds) and the ability to query nearby drivers within a radius. The company expects millions of drivers and trips. Which AWS database service should the database specialist recommend for storing real-time driver locations and supporting proximity queries?
230A company runs a multi-tenant SaaS application on Amazon RDS for PostgreSQL. Each tenant has an isolated database. Recently, the application experienced a sudden increase in connection errors and slow query performance. Amazon RDS instance metrics show high CPU utilization and a high number of database connections. The application uses connection pooling with PgBouncer running on an EC2 instance. The team suspects the issue is due to a few noisy tenants opening too many connections. The current architecture uses one RDS instance per tenant. The company wants to optimize for workload-specific database design to handle noisy tenants without affecting other tenants. Which design should be implemented to isolate noisy tenants and reduce costs?
231A financial services company uses Amazon DynamoDB to store transaction records. Each transaction has a partition key of customer_id and a sort key of transaction_timestamp. The application queries transactions for a specific customer within a date range. Recently, the query latency increased significantly for customers with a large number of transactions. The company needs to improve query performance without changing the application code. The table is provisioned with 5000 RCUs and 2000 WCUs. Which design change should be made to optimize for this workload?
232A company is migrating an on-premises Oracle database to Amazon Aurora PostgreSQL. The database contains a large table that is partitioned by date. The company wants to minimize downtime during migration and ensure compatibility. Which TWO actions should the company take?
233A gaming company uses Amazon ElastiCache for Redis as a leaderboard for real-time game scores. The leaderboard is updated frequently by millions of users. The application uses sorted sets with player scores. Recently, the leaderboard update latency increased and the cache evictions spiked. The company needs to ensure low-latency updates and high availability. The current setup is a single Redis node. Which design should be implemented?
234A company is designing a highly available e-commerce application using Amazon DynamoDB. The application requires strongly consistent reads for inventory data and eventual consistency for user session data. Which TWO design decisions should the company make?
235A media company stores video metadata in Amazon DynamoDB. Each record has a partition key of video_id and a sort key of uploaded_timestamp. The application frequently queries videos by genre and upload date. The access pattern is read-heavy with occasional writes. The table is provisioned with 3000 RCUs and 1000 WCUs. The company notices that queries by genre are slow and consume many RCUs. Which design change should be made to optimize for this workload?
236A healthcare company stores patient records in Amazon DynamoDB. Each record includes patient_id (partition key), visit_date (sort key), and a large JSON attribute for medical history. The application frequently queries recent visits for a patient and scans historical data for analytics. The scans on the medical history attribute cause high RCU consumption. The company wants to reduce costs and improve query performance. Which design should be implemented?
237A company is designing a new application that requires a relational database with read replicas for reporting. The application has unpredictable traffic patterns. The company wants to minimize operational overhead and automatically scale compute capacity. Which THREE services should the company consider?
238A startup is building a social media application that stores user posts in Amazon DynamoDB. The access pattern is to retrieve posts by user_id (partition key) sorted by post_timestamp (sort key) in descending order. The table has a global secondary index (GSI) with the same key structure but with different projection. The application reads from the GSI. Recently, the team noticed that writes to the base table are throttled during peak hours. The write capacity is balanced across partitions. Which design change should be made to reduce write throttling?
239A company runs an OLTP application on Amazon RDS for PostgreSQL. The database stores customer orders. The application frequently queries orders by customer_id and order_date. The orders table has 100 million rows. The query performance has degraded over time. The database has a single index on customer_id. The company needs to improve query performance without changing the application code. Which design change should be made?
240A company uses Amazon DynamoDB to store IoT sensor data. Each sensor sends data every minute. The table has a partition key of sensor_id and a sort key of timestamp. The application queries data for a sensor over the last hour. The table uses on-demand capacity. Recently, the query latency increased for sensors that generate a high volume of data. The application retrieves all attributes for the sensor data. Which design change should be made to reduce latency?
241A company is migrating a self-managed MongoDB database to Amazon DocumentDB. The database stores user profiles and activity logs. The activity logs are write-heavy and accessed infrequently. The company wants to optimize cost and performance for the workload. Which THREE design decisions should the company make?
242A company runs a reporting application on Amazon Redshift. The application queries a large fact table that is distributed by a key. The report queries filter on a date column. The report performance is slow. The database has 10 nodes. The company wants to improve query performance by optimizing the table design. Which design change should be made?
243A company uses Amazon RDS for MySQL to store e-commerce order data. The orders table has millions of rows and is frequently queried by order_id. The company also runs periodic reports that aggregate data by order_date. The reports are slow. The database has a primary key on order_id. The company needs to improve report performance without affecting OLTP queries. Which design change should be made?
244A company is designing a disaster recovery strategy for an Amazon RDS for PostgreSQL database. The database is 2 TB in size. The company wants to recover to a different AWS Region with minimal data loss. Which TWO options meet these requirements?
245A company is migrating its on-premises MySQL database to Amazon Aurora MySQL. The current database has a table of 500 GB that is accessed by a nightly batch job that updates 80% of the rows. The company wants to minimize downtime during migration. Which migration strategy is MOST appropriate?
246A social media application uses Amazon DynamoDB with a table that has a partition key of 'user_id' and a sort key of 'post_timestamp'. The application frequently queries for the 10 most recent posts by a specific user. The query pattern uses a 'begins_with' condition on the sort key with a timestamp prefix. Recently, the query latency has increased significantly for users with many posts. Which design change would improve query performance?
247A company runs an online transaction processing (OLTP) workload on Amazon RDS for PostgreSQL. The database has grown to 2 TB and the company needs to run complex analytical queries that join multiple large tables. These analytical queries are slowing down the OLTP operations. What is the MOST cost-effective solution to separate the workloads?
248A gaming company uses Amazon DynamoDB for player profiles. The access pattern is to retrieve a player's profile by 'player_id'. Each profile includes a list of 'achievements' that can grow up to 400 KB. Recently, the application has been encountering 'ProvisionedThroughputExceededException' errors. The table has 1000 read capacity units (RCU) and 500 write capacity units (WCU). The average item size is 200 KB. What is the MOST likely cause of the throttling?
249An e-commerce application stores order data in Amazon RDS for MySQL. The database has grown to 1.5 TB and the company needs to retain data for 7 years for compliance. Current queries are becoming slow due to the large table size. The compliance requirement mandates that data older than 1 year must be retained but is rarely accessed. What strategy would reduce the active table size while maintaining compliance?
250A company is designing a document storage system using Amazon DynamoDB. Each document is up to 400 KB and is identified by a unique 'document_id'. The access pattern is to retrieve a document by its ID. Which DynamoDB table design is MOST efficient?
251A company is migrating a large Oracle Data Warehouse (10 TB) to Amazon Redshift. The current system uses complex stored procedures, materialized views, and window functions. The company wants to minimize migration effort. Which approach is MOST suitable?
252A company runs a MySQL database on Amazon RDS and wants to capture data changes to replicate to a separate reporting database. Which AWS service should be used to capture these changes with minimal impact on the source database?
253A company is designing a time-series database for IoT sensor data using Amazon DynamoDB. Each sensor sends a reading every second. The table uses 'sensor_id' as partition key and 'timestamp' as sort key. The application queries for the last hour of data for a specific sensor. The query uses 'KeyConditionExpression' with 'timestamp' between start and end time. The table has auto-scaling enabled. However, the query latency is high. What is the MOST likely cause?
254A company is designing a database for a global e-commerce platform. The application requires single-digit millisecond read and write latency for user sessions, and must handle millions of requests per second. The data is key-value in nature. Which TWO AWS services should the company consider? (Choose two.)
255A company is migrating a 3 TB Oracle database to Amazon Aurora PostgreSQL. The database has a heavy OLTP workload with many small transactions. The migration must have minimal downtime. Which TWO strategies should the company use? (Choose two.)
256A company is building a real-time leaderboard for a mobile game using Amazon DynamoDB. The leaderboard displays the top 100 players by score. The table has 'game_id' as partition key and 'player_id' as sort key. The score is updated frequently. Which THREE design patterns should the company implement to ensure low-latency reads for the leaderboard? (Choose three.)
257A gaming company runs a global leaderboard on Amazon DynamoDB. The leaderboard is updated frequently and must return the top 100 scores in milliseconds. The current design uses a single table with a Global Secondary Index (GSI) on score. However, the query to retrieve top scores often throttles under load. Which design change would best improve performance?
258A financial services company uses Amazon RDS for MySQL with Multi-AZ and read replicas. The application suddenly reports increased write latency. The DB instance is a db.r5.large with 300 GB of General Purpose SSD (gp2) storage. CloudWatch metrics show Write IOPS is at 2,500 and Write Latency averages 50 ms. What is the most likely cause?
259A startup is building a social media application with a news feed feature. The feed must be personalized and updated in real-time as users post. Which AWS database service is best suited for this workload?
260A company is migrating an on-premises Oracle database with complex stored procedures and triggers to AWS. They want to minimize code changes. Which two AWS database services should they consider? (Choose two.)
261A company runs an e-commerce platform on Amazon Aurora MySQL. The platform experiences high traffic during flash sales. To handle the load, they want to offload read traffic to read replicas. However, they are concerned about replication lag causing stale data for inventory checks. Which three strategies can reduce replication lag? (Choose three.)
262A company wants to store session state for a web application that runs on Amazon EC2 instances behind an Application Load Balancer. The session data is ephemeral and must be highly available. Which two AWS services are suitable for this use case? (Choose two.)
263An application using the above IAM policy is trying to perform a Scan operation on the 'Orders' table. What will happen?
264A developer is designing a DynamoDB table for an order management system using the above CloudFormation template. The application needs to query orders by CustomerID. The current design has a GSI on CustomerID. However, the developer notices that the GSI has low write throughput and often throttles. What is the most cost-effective way to improve write throughput on the GSI?
265An application is receiving the error shown in the exhibit. The application uses connection pooling. The RDS instance is a db.r5.large with max_connections set to 1000. What is the most likely cause?
266A company needs to store time-series data from IoT sensors. Each sensor sends a reading every minute. The data is rarely accessed after 30 days. The query pattern is to retrieve all readings for a specific sensor within a time range. Which AWS database is most cost-effective?
267A company runs a global application using Amazon Aurora Global Database. The primary region is us-east-1, and secondary regions are eu-west-1 and ap-southeast-1. The application reports that writes to the primary are taking longer than expected. What is the most likely cause?
268A company uses Amazon DynamoDB to store user profiles. The access pattern is mostly GetItem by user_id. They want to reduce costs. Which design change is most effective?
269A company needs to store and query graph data (nodes and edges) for a social network. They require low-latency traversals. Which AWS database is best suited?
270A data analyst reports that a nightly ETL job to Amazon Redshift is failing with timeout errors shown in the exhibit. The cluster is a dc2.large with 2 nodes. The ETL job inserts large volumes of data. What is the most likely cause?
271A company is designing a document management system using Amazon DocumentDB. Each document is up to 10 MB. The application needs to retrieve multiple documents by their IDs in a single request. The IDs are known at query time. Which query pattern is most efficient?
272A social media application stores user posts in a DynamoDB table with a partition key of user_id and a sort key of timestamp. The most frequent query is to retrieve the 10 most recent posts for a given user. Which secondary index design would optimize this query?
273A company runs an OLTP workload on an RDS for MySQL instance. The database has a table with 50 million rows. The application frequently runs queries that join this table with a small lookup table (1000 rows) using a foreign key. The queries are slow. Which design change would most improve performance?
274A startup wants to store session data for a web application. Each session is small (under 1 KB) and accessed frequently with low latency. The data can be ephemeral and does not require complex queries. Which AWS database service is most suitable?
275A company is designing a database for a global IoT application that ingests millions of events per second. Each event includes a device ID, timestamp, and sensor readings. The requirement is to store data for historical analysis and to support queries that aggregate data by device ID over time ranges. The team needs a cost-effective solution that can scale write throughput. Which database design is most appropriate?
276A company runs a financial application that requires ACID transactions on a relational database. The workload has a high volume of writes and reads, and the team wants to minimize operational overhead. Which AWS database service should they choose?
277A gaming company wants to store player profiles and game state. The data is accessed via a REST API and must be highly available with single-digit millisecond latency. The schema is simple and may evolve over time. Which database should they use?
278A company has a multi-player game that uses DynamoDB to store game state. The access pattern is write-heavy, and the game state for each active game session is updated frequently. The team notices throttling on the table during peak hours. The table has a partition key of game_id and no sort key. What design change would best reduce throttling?
279A company is migrating an on-premises Oracle data warehouse to AWS. The warehouse contains 50 TB of data and runs complex queries that involve joins and aggregations. The team wants to minimize migration effort and cost while maintaining query performance. Which AWS service should they use?
280A company needs to store and query JSON documents that have varying attributes. The workload is read-heavy, and the team wants to use SQL-like queries. Which service is most appropriate?
281Which TWO factors should you consider when choosing between Amazon RDS and Amazon DynamoDB for a new application?
282Which THREE design patterns are commonly used to optimize DynamoDB performance for write-heavy workloads?
283Which TWO of the following are advantages of using Amazon Aurora over standard RDS for MySQL?
284A company is designing a database for an e-commerce platform that stores product catalog data. The catalog has frequent reads and occasional writes. The data is highly relational but the team wants the lowest possible latency for read queries. Which database service should they choose?
285A financial services company runs a core banking application on Amazon RDS for MySQL. They need to maintain a full audit trail of all changes to customer account balances for regulatory compliance. The audit trail must be immutable and queryable for up to 7 years. Which solution meets these requirements with minimal impact on the source database?
286A startup is building a social media application. User profiles, posts, and comments have relationships but the team expects rapid growth and wants to scale horizontally with no single points of failure. They need a database that supports flexible schemas for different content types. Which database service is most appropriate?
287A company is running a MongoDB-compatible workload on Amazon DocumentDB. They are experiencing high write latency during peak hours. The current cluster has one instance (db.r5.large) with 100 GB storage. Which change is most likely to improve write performance?
288A company uses Amazon RDS for PostgreSQL to store sensor data. Each sensor sends a row every second. The table has grown to 500 GB and queries filtering on a timestamp column are slow even with an index. The team wants to improve query performance while keeping the data online. Which approach should they take?
289A mobile gaming company needs a database to store player scores and leaderboards. The data must be updated in real time as players finish games. The database must support high write throughput and provide sub-millisecond read latency for leaderboard queries. Which database is best suited?
290A company uses Amazon RDS for Oracle with a Multi-AZ deployment for a critical OLTP application. During a recent failover test, they noticed that the application experienced a two-minute downtime. The team wants to reduce downtime to under 30 seconds during automatic failovers. What should they do?
291A company runs a web application on Amazon EC2 instances behind an Application Load Balancer. The application uses Amazon RDS for MySQL. Recently, the database CPU utilization spikes to 100% during peak hours. The team observes that the spike is caused by a large number of slow queries. They need to identify and resolve the issue with minimal disruption. Which combination of steps should they take? (Choose two.)
292A company is migrating an on-premises MySQL database to Amazon Aurora MySQL. The database is 2 TB and the migration must have minimal downtime. The network bandwidth between the on-premises data center and AWS is 1 Gbps. Which migration approach is most appropriate?
293A company needs to store and analyze JSON documents that contain nested fields. The data is used for real-time dashboards and ad-hoc queries. The team wants a fully managed solution that supports both key-value lookups and SQL-like queries. Which AWS service should they use?
294A company uses Amazon DynamoDB for a session management store. The application writes and reads session data frequently. The team notices that write requests occasionally fail with ProvisionedThroughputExceededException. They want a cost-effective solution to handle these bursts. What should they do?
295A company has a MySQL database that stores user profile data. The database is 1 TB and growing. The team wants to archive inactive user profiles that haven't been accessed in over 1 year. The archived data must be queryable but at a slower performance tier. Which approach is most cost-effective?
296A company is designing a database for a global application that requires active-active replication across two AWS Regions. The database must support multi-master writes with conflict resolution. Which AWS database service should they use?
297A company runs a critical Oracle database on Amazon RDS. The database has a large table that is frequently accessed by multiple applications. The team wants to implement caching to reduce the load on the database. The cached data must be strongly consistent with the database. Which caching strategy should they use?
298A company is building a real-time analytics dashboard for IoT sensor data. The data arrives as JSON and needs to be stored in a way that supports fast ingestion and complex queries. Which database service is best suited?
299A company needs to store and manage user sessions for a web application. The application runs on multiple EC2 instances, and sessions must be accessible from any instance. The team wants a fully managed, highly available, and low-latency solution. Which AWS service should they use?
300A company uses Amazon Aurora MySQL for an OLTP application. The database has a buffer pool cache hit ratio of 99%. However, the application still experiences high latency for some queries. Which of the following is the most likely cause? (Choose two.)
The Workload-Specific Database Design domain covers the key concepts tested in this area of the DBS-C01 exam blueprint published by Amazon Web Services. Courseiva provides free domain-focused practice, mock exams, missed-question review, and readiness tracking across all DBS-C01 domains — no account required.
The Courseiva DBS-C01 question bank contains 300 questions in the Workload-Specific Database Design domain. Click any question to see the full explanation and answer breakdown.
Start with a 10-question focused session to identify your baseline accuracy in this domain. Read every explanation — even for questions you answer correctly — to understand the reasoning. Once you score consistently above 80%, move to a 20–30 question session to confirm depth before moving to the next domain.
Yes — the session launcher on this page draws questions exclusively from the Workload-Specific Database Design domain. Choose 10, 20, 30, or 50 questions for a focused session, or click individual questions to review them one by one.
Save your results, see per-domain analytics, and get readiness scores — free, for every certification.
Sign Up FreeFree forever · Every certification included