DEA-C01 Data Ingestion and Transformation Practice Test 14 — 15 Questions

Question 1

A data engineer is designing a data ingestion pipeline for IoT sensor data. The data is generated at a high velocity and must be processed in near real-time. The pipeline must also handle bursty traffic. Which TWO AWS services should be combined to achieve this? (Choose TWO.)

Accepted Answer

Amazon Kinesis Data Analytics. Option A (Kinesis Data Streams) is correct because it can ingest high-velocity streaming data and handle bursty traffic. Option C (Kinesis Data Analytics) is correct because it can perform real-time processing. Option B is wrong because SQS is for decoupling, not real-time streaming. Option D is wrong because Glue is more batch. Option E is wrong because S3 is not real-time.

Answer

Amazon S3

Answer

Amazon Simple Queue Service (SQS)

Answer

AWS Glue

Question 2

A company uses AWS Glue to transform data stored in S3. The Glue job runs daily and processes data in the range of hundreds of GB. The data engineer wants to optimize the job for cost and performance. Which THREE actions should be taken? (Choose THREE.)

Accepted Answer

Increase the number of DPUs for the job. Option A is correct because using columnar formats like Parquet improves performance and reduces data scanned. Option B is correct because partitioning reduces data processed. Option D is correct because increasing the number of DPUs can speed up the job, but must be balanced with cost. Option C is wrong because S3 is already the source; moving to HDFS is not relevant. Option E is wrong because reducing DPUs would increase runtime.

Answer

Store intermediate data in HDFS on Amazon EMR

Answer

Reduce the number of DPUs to save cost

Question 3

A data engineer needs to transfer 50 TB of data from an on-premises data center to Amazon S3 over a 1 Gbps network. The transfer must be completed within one week. Which TWO AWS services can be used for this task? (Choose TWO.)

Accepted Answer

AWS DataSync. Option A (AWS DataSync) is correct because it can transfer large volumes over the network efficiently. Option D (AWS Snowball) is correct because it can be used for offline transfer if network is insufficient. Option B is wrong because S3 Transfer Acceleration only speeds up internet transfers but not necessarily achieve the required throughput. Option C is wrong because Direct Connect is a network connection, not a transfer service. Option E is wrong because Glue is for ETL, not bulk transfer.

Answer

AWS Glue

Answer

Amazon S3 Transfer Acceleration

Answer

AWS Direct Connect

Question 4

A company uses Kinesis Data Streams to ingest clickstream data. They notice that the data processing latency increases as the number of shards grows. What is the most likely cause and solution?

Accepted Answer

Reduce the number of shards or increase the number of consumers.. Option D is correct because when there are more shards than consumers, some shards are idle, leading to underutilization and increased latency. Option A is wrong because increasing shards would worsen the imbalance. Option B is wrong because enhanced fan-out is for multiple consumers, not single consumer. Option C is wrong because increasing batch size might help throughput but not the fundamental shard-consumer mismatch.

Answer

Increase the Kinesis Producer Library (KPL) batch size.

Answer

Use enhanced fan-out to allow multiple consumers per shard.

Answer

Increase the number of shards to handle more data.

Question 5

A data engineer needs to ingest JSON files from an S3 bucket into a DynamoDB table. The files are updated hourly and contain new records. Which AWS service should be used to trigger a Lambda function for each new object?

Accepted Answer

S3 Event Notifications. Option A is correct because S3 Event Notifications can invoke Lambda on PutObject events. Option B is wrong because Kinesis is for streaming, not event-based S3 triggers. Option C is wrong because SQS would require polling. Option D is wrong because EventBridge is more complex for simple S3 object creation triggers.

Answer

Kinesis Data Firehose

Answer

Amazon EventBridge

Answer

Amazon SQS

Question 6

A company uses AWS Glue ETL jobs to transform data in S3. The job runs successfully but takes longer than expected. The data is in Parquet format and partitioned by date. Which change would most improve performance without increasing cost?

Accepted Answer

Enable pushdown predicates to filter partitions early.. Option B is correct because enabling pushdown predicates filters partitions at the source, reducing data scanned. Option A is wrong because increasing DPUs increases cost. Option C is wrong because converting to CSV increases data size and scan time. Option D is wrong because repartitioning may cause shuffling overhead.

Answer

Repartition the data by a different column.

Answer

Convert Parquet to CSV for faster serialization.

Answer

Increase the number of DPUs for the job.

Question 7

A data engineer is designing a streaming pipeline that ingests IoT sensor data from 10,000 devices. Each device sends a 1 KB message every second. The data must be processed in near real-time and stored in S3 for analytics. Which combination of services provides the most cost-effective solution?

Accepted Answer

Amazon Kinesis Data Streams with Kinesis Data Firehose delivery to S3.. Option B is correct because Kinesis Data Streams ingests high-throughput data, and Firehose delivers batches to S3 with optional Lambda transformations. Option A is wrong because SQS FIFO is not designed for high-throughput streaming. Option C is wrong because MSK requires more management. Option D is wrong because Data Pipeline is batch-oriented.

Answer

AWS Data Pipeline with periodic S3 copy.

Answer

Amazon MSK (Managed Streaming for Kafka) with Kafka Connect S3 sink.

Answer

Amazon SQS FIFO queue with Lambda consumers writing to S3.

Question 8

A company runs a nightly ETL job using AWS Glue. The job reads data from a JDBC connection to an on-premises MySQL database. The job fails with an error indicating that the connection pool is exhausted. What is the most likely cause and solution?

Accepted Answer

The Glue job is using too many executors, exhausting the database connections. Reduce the number of DPUs or increase the database max connections.. Option A is correct because high parallelism in Glue creates many connections, overwhelming the database. Option B is wrong because network issues would cause timeouts, not pool exhaustion. Option C is wrong because Glue does not have connection pool limits. Option D is wrong because password rotation would cause authentication errors.

Answer

The database is not reachable due to network issues. Check VPC and security groups.

Answer

The Glue job is hitting the AWS Glue connection pool limit. Increase the Glue connection pool size.

Answer

The database credentials are expired. Rotate the password in AWS Secrets Manager.

Question 9

A data engineer needs to transform CSV files to Parquet format using AWS Glue. The source data contains sensitive columns that must be masked. Which Glue feature should be used?

Accepted Answer

AWS Glue DataBrew. Option B is correct because Glue DataBrew provides built-in transformations like masking. Option A is wrong because Glue Studio is for building visual ETL jobs but not specifically for masking. Option C is wrong because Glue crawlers catalog data, not transform. Option D is wrong because Glue Schema Registry manages schemas.

Answer

AWS Glue Studio

Answer

AWS Glue Crawler

Answer

AWS Glue Schema Registry

Question 10

A data pipeline ingests streaming data from Kinesis Data Streams into S3 via Kinesis Data Firehose. Occasionally, small files are written to S3, increasing downstream processing costs. What is the most efficient way to reduce the number of small files?

Accepted Answer

Increase the Firehose buffering interval to 300 seconds and buffering size to 64 MB.. Option C is correct because increasing the buffering interval and size in Firehose batches more data into fewer files. Option A is wrong because Lambda can aggregate but adds complexity and cost. Option B is wrong because KCL runs on EC2, not serverless. Option D is wrong because Glue ETL runs after delivery, not preventing small files.

Answer

Use a Lambda function to aggregate records before sending to Firehose.

Answer

Use the Kinesis Client Library (KCL) to write larger batches to S3 directly.

Answer

Run a daily AWS Glue job to concatenate small files.

Question 11

A company uses AWS Database Migration Service (DMS) to continuously replicate data from an Oracle RDS instance to S3. The data is used for analytics. The replication lags behind the source by several hours. Which change would most likely reduce the lag?

Accepted Answer

Use a larger DMS replication instance (e.g., dms.c5.large instead of dms.t3.medium).. Option A is correct because using a larger instance provides more CPU and memory for DMS. Option B is wrong because S3 endpoint cannot be changed to Kinesis without redesign. Option C is wrong because increasing source RDS storage doesn't directly impact DMS performance. Option D is wrong because changing target to Parquet adds transformation overhead.

Answer

Change the target endpoint from S3 to Kinesis Data Firehose.

Answer

Increase the source RDS instance storage to improve I/O.

Answer

Change the target data format from CSV to Parquet.

Question 12

A data engineer needs to ingest data from an external FTP server into S3 on a schedule. The FTP server is only accessible via VPN. Which AWS service is best suited for this task?

Accepted Answer

AWS Transfer Family. Option D is correct because AWS Transfer Family supports FTP over VPN. Option A is wrong because DataSync requires network connectivity but not FTP protocol. Option B is wrong because Glue can read from FTP but requires custom connectors. Option C is wrong because Snowcone is for offline data transfer.

Answer

AWS Snowcone

Answer

AWS Glue with a Python shell

Answer

AWS DataSync

Question 13

A data engineer is designing a near-real-time streaming pipeline to ingest clickstream data from a web application. The data must be enriched with user metadata from a DynamoDB table before being stored in S3. Which combination of AWS services should the engineer use? (Choose TWO.)

Accepted Answer

Amazon Kinesis Data Analytics for Apache Flink. Option A and Option C are correct because Kinesis Data Streams ingests the clickstream, and Kinesis Data Analytics for Apache Flink can enrich streams with DynamoDB lookups. Option B is wrong because Lambda can enrich but is limited by concurrency. Option D is wrong because Firehose can transform via Lambda but not DynamoDB enrichment directly. Option E is wrong because Glue is batch, not streaming.

Answer

Amazon Kinesis Data Firehose

Answer

AWS Lambda with DynamoDB Accelerator (DAX)

Answer

AWS Glue Streaming ETL

Question 14

A company uses a Kinesis Data Firehose delivery stream to load data into an S3 bucket. The data is in JSON format and must be converted to Parquet before landing in S3. Which steps are required to achieve this? (Choose THREE.)

Accepted Answer

Configure the Firehose delivery stream to enable data format conversion to Parquet.. Option A, Option C, and Option E are correct because Firehose can convert to Parquet using a schema from a Glue table, and the table must be registered in the Data Catalog. Option B is wrong because Firehose does not use DynamoDB. Option D is wrong because Kinesis Data Analytics is for stream processing, not conversion.

Answer

Store the schema in Amazon DynamoDB.

Answer

Use Kinesis Data Analytics to convert the data.

Question 15

A data engineer needs to ingest data from a SaaS application that sends webhooks in JSON format. The data must be stored in S3 for batch analysis. Which AWS services can receive the webhooks and store the data in S3 with minimal custom code? (Choose TWO.)

Accepted Answer

Amazon API Gateway with S3 integration. Option A and Option D are correct because API Gateway can receive webhooks and route to Firehose or S3. Option B is wrong because Glue cannot directly receive webhooks. Option C is wrong because Kinesis Data Streams requires custom producers. Option E is wrong because Lambda can receive but not directly store to S3 without code.

Answer

AWS Lambda with S3 SDK

Answer

AWS Glue with a Python shell job

Answer

Amazon Kinesis Data Streams