DEA-C01 Data Store Management Practice Test 19 — 15 Questions

Question 1

A company has an Amazon S3 bucket with versioning enabled. They want to automatically delete noncurrent versions of objects after 30 days. Which lifecycle rule action should be used?

Accepted Answer

NoncurrentVersionExpiration. The NoncurrentVersionExpiration lifecycle action is specifically designed to remove noncurrent object versions after a specified number of days. Since versioning is enabled and the requirement is to delete noncurrent versions after 30 days, this action directly meets the goal without affecting current versions or other lifecycle aspects.

Answer

Expiration

Answer

NoncurrentVersionTransition

Answer

AbortIncompleteMultipartUpload

Question 2

A data engineer is designing a data lake on Amazon S3. The data is frequently accessed by multiple analytics services, and the company needs to enforce fine-grained access control based on data tags. Which combination of AWS services should be used?

Accepted Answer

AWS Lake Formation with tag-based access control. AWS Lake Formation with tag-based access control (TBAC) is the correct choice because it provides fine-grained, attribute-based access control (ABAC) at the column, row, and cell level across a data lake on S3. By assigning LF-tags to Data Catalog resources and defining permissions based on those tags, you can enforce granular access policies that scale without managing individual user-to-resource mappings. This directly meets the requirement for tag-driven, fine-grained access for multiple analytics services.

Answer

S3 Block Public Access settings

Answer

S3 Access Points with bucket policies

Answer

S3 Object Lambda with IAM policies

Question 3

Which TWO of the following are benefits of using Amazon DynamoDB Accelerator (DAX)? (Choose TWO.)

Accepted Answer

Provides microsecond read latency. Amazon DynamoDB Accelerator (DAX) is an in-memory cache that sits between your application and DynamoDB, providing microsecond response times for read-heavy workloads. It achieves this by caching frequently accessed data in memory, reducing the latency from single-digit milliseconds to microseconds for eventually consistent reads.

Answer

Improves write throughput

Answer

Provides data durability across Availability Zones

Answer

Reduces storage costs

Question 4

Which THREE of the following are valid storage classes in Amazon S3? (Choose THREE.)

Accepted Answer

S3 Standard. S3 Standard is a valid storage class designed for frequently accessed data with low latency and high throughput. It offers 99.999999999% durability and 99.99% availability, making it suitable for a wide range of use cases like cloud applications, dynamic websites, and content distribution.

Answer

S3 Archive

Answer

S3 Cold

Question 5

Which TWO of the following are best practices for Amazon Redshift table design? (Choose TWO.)

Accepted Answer

Choose sort keys based on query patterns. Options A and D are correct. Choosing sort keys based on query patterns optimizes data organization for faster retrieval, and specifying distribution keys minimizes data movement across nodes. Option B is wrong because large data loads should use the COPY command, not INSERT statements. Option C is wrong because compression encoding reduces storage and I/O, improving performance despite slightly higher CPU overhead. Option E is wrong because setting distribution style to ALL for all tables can cause excessive data duplication and storage costs; distribution keys should be selected based on table size and join patterns.

Answer

Use INSERT statements for large data loads

Answer

Avoid compression encoding to reduce CPU overhead

Answer

Set distribution style to ALL for all tables

Question 6

A company is using Amazon S3 to store sensitive data. To meet compliance requirements, they need to automatically transition objects to S3 Glacier Deep Archive after 90 days and delete them after 7 years. What is the MOST cost-effective way to configure this?

Accepted Answer

Configure an S3 Lifecycle policy to transition objects to Glacier Deep Archive after 90 days and expire them after 7 years.. An S3 Lifecycle policy can automate both the transition of objects to S3 Glacier Deep Archive after 90 days and their expiration (permanent deletion) after 7 years. This is the most cost-effective approach as it eliminates manual effort and leverages S3's native, serverless lifecycle management, which incurs no additional cost beyond the storage and transition fees.

Answer

Manually move objects to Glacier Deep Archive and delete them using a script.

Answer

Use S3 Intelligent-Tiering to automatically move objects to Glacier Deep Archive and set expiration.

Answer

Enable S3 Object Lock with a retention period of 7 years and use a lifecycle policy to transition to Glacier Deep Archive.

Question 7

A data engineer needs to store JSON documents that are frequently read and written by a web application. The data has a flexible schema and requires low-latency queries on primary key lookups. Which AWS service is MOST suitable?

Accepted Answer

Amazon DynamoDB. Amazon DynamoDB is the most suitable service because it is a NoSQL key-value and document database that provides single-digit millisecond latency for primary key lookups, supports flexible schemas for JSON documents, and is designed for high-throughput read/write workloads from web applications. Its fully managed nature and auto-scaling capabilities align with the requirement for frequent, low-latency queries on a flexible schema.

Answer

Amazon Redshift

Answer

Amazon S3

Answer

Amazon RDS for MySQL

Question 8

A company runs a critical transactional database on Amazon RDS for PostgreSQL. They need to achieve high availability with automatic failover to a different AWS Region in case of a regional outage. Which solution meets these requirements?

Accepted Answer

Use Amazon Aurora Global Database with a primary cluster in one Region and a secondary in another.. Amazon Aurora Global Database is designed for cross-Region disaster recovery, replicating data with a typical latency of under one second and providing automatic failover from the primary Region to a secondary Region. This meets the requirement of high availability with automatic failover during a regional outage, unlike standard RDS options which lack built-in cross-Region automatic failover.

Answer

Create a cross-Region Read Replica and promote it during a disaster.

Answer

Take daily automated snapshots and restore them in another Region.

Answer

Deploy the RDS instance in a Multi-AZ configuration.

Question 9

A data engineer is designing a data lake on Amazon S3. The data is ingested from multiple sources in Parquet format, and the schema evolves over time. Which approach allows querying the data with Amazon Athena while supporting schema evolution?

Accepted Answer

Use AWS Glue Data Catalog with crawlers to automatically update the table schema.. AWS Glue Data Catalog with crawlers automatically infers and updates the table schema as new Parquet files with evolving schemas are ingested into S3. This allows Athena to query the data using the latest schema without manual intervention, making it the ideal solution for schema evolution in a data lake.

Answer

Define Hive-style partitions in Athena and manually update the schema.

Answer

Use S3 Select to query the data directly without a schema.

Answer

Use Amazon Redshift Spectrum with external tables and update the schema manually.

Question 10

A company needs to store relational data that requires complex joins and transactional consistency. The workload is predictable and the data size is less than 500 GB. Which AWS service is MOST cost-effective for this use case?

Accepted Answer

Amazon RDS for PostgreSQL. Amazon RDS for PostgreSQL is the most cost-effective choice because it provides a fully managed relational database service that supports complex joins and transactional consistency (ACID compliance) for predictable workloads under 500 GB. Unlike Redshift, which is optimized for petabyte-scale analytics, RDS offers lower cost for this data size and workload pattern, while DynamoDB lacks native SQL join capabilities and S3 is not a relational database.

Answer

Amazon Redshift

Answer

Amazon S3

Answer

Amazon DynamoDB

Question 11

A company is migrating an on-premises Hadoop cluster to AWS. The cluster processes large files in CSV format using Apache Spark. Which data store should be used as the primary storage for the data lake to optimize cost and performance?

Accepted Answer

Amazon S3. Amazon S3 is the most suitable primary storage for a data lake on AWS due to its high durability, scalability, and cost-effectiveness. It integrates seamlessly with Amazon EMR and Apache Spark for processing large CSV files. Option A is wrong because EMRFS is a connector that allows EMR to access data in S3, not a separate storage system; it is not an alternative to HDFS. Option B is wrong because Amazon RDS for MySQL is a relational database service, not designed for storing large-scale data lake files like CSV. Option C is wrong because Amazon EBS volumes are block-level storage for EC2 instances, which are limited in scalability and not cost-effective for large data lakes, especially when used as primary storage.

Answer

Amazon EMR File System (EMRFS) backed by HDFS

Answer

Amazon RDS for MySQL

Answer

Amazon EBS volumes attached to the EMR cluster

Question 12

A company has an Amazon Redshift cluster with a mix of frequently accessed hot data and rarely accessed cold data. They want to reduce storage costs without affecting query performance for the hot data. Which strategy is MOST effective?

Accepted Answer

Use RA3 nodes with managed storage to automatically offload cold data to Amazon S3.. RA3 nodes with managed storage automatically separate compute and storage, offloading cold data to Amazon S3 while keeping hot data on local SSD for fast queries. This reduces storage costs without manual intervention or affecting hot data performance.

Answer

Reduce the number of nodes and increase the number of slices.

Answer

Create external tables in Redshift Spectrum to query cold data in S3.

Answer

Use Dense Compute nodes and unload cold data to Amazon S3 manually.

Question 13

A company needs to store archival logs that must be retained for 10 years. The logs are accessed infrequently, but when accessed, retrieval must occur within 12 hours. Which storage class is MOST cost-effective?

Accepted Answer

Amazon S3 Glacier Deep Archive. Amazon S3 Glacier Deep Archive is the most cost-effective storage class for archival logs that must be retained for 10 years with infrequent access and a 12-hour retrieval window. It offers the lowest storage cost among S3 classes, with retrieval times typically within 12 hours for standard retrievals, making it ideal for long-term archival data that is rarely accessed.

Answer

Amazon S3 Intelligent-Tiering

Answer

Amazon S3 Standard

Answer

Amazon S3 One Zone-Infrequent Access

Question 14

A company is using Amazon S3 to store sensitive financial data. They need to ensure that all objects are encrypted at rest. Which TWO methods can achieve this? (Choose TWO.)

Accepted Answer

Use SSE-KMS to encrypt objects with AWS KMS.. SSE-KMS (Server-Side Encryption with AWS Key Management Service) allows you to encrypt objects at rest in S3 using customer-managed or AWS-managed KMS keys. This provides envelope encryption, separate key management, and audit trails via AWS CloudTrail, meeting compliance requirements for sensitive financial data.

Answer

Enable S3 Transfer Acceleration on the bucket.

Answer

Apply a bucket policy that denies PutObject without encryption.

Answer

Use client-side encryption before uploading objects.

Question 15

A company is designing a multi-Region disaster recovery solution for Amazon DynamoDB. They need to ensure that data is replicated across Regions with minimal latency and that applications can read from any Region. Which THREE steps should be taken? (Choose THREE.)

Accepted Answer

Configure application to read from any Region using the DynamoDB endpoint.. DynamoDB Global Tables provide multi-Region, multi-master replication, allowing applications to read from any Region by simply pointing to the local DynamoDB endpoint. This ensures low-latency reads by serving data from the closest Region, and the replication is fully managed by DynamoDB.

Answer

Configure Time to Live (TTL) to automatically expire old data.

Answer

Deploy DynamoDB Accelerator (DAX) in each Region.