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AWS Certified Machine Learning Specialty MLS-C01 Practice Test

1,755 questions with instant explanations, domain breakdown, and wrong-answer analysis. Built for the real exam.

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Domain score breakdown
Real exam: 180 min
Pass mark: 750%

Sample questions with explanations

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Q1Data Engineeringmedium
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A data science team uses Amazon SageMaker to train models on a large dataset stored in S3. The dataset is 500 GB in CSV format and is updated daily. The team wants to optimize data loading for training jobs to reduce I/O wait time. Which data ingestion strategy is MOST effective?

AUse SageMaker File input mode and increase the EBS volume size to 1 TB.
Use SageMaker Pipe input mode to stream data directly from S3.Correct
CConvert the CSV files to Parquet format and use File input mode.
DLoad the data into an Amazon EFS file system and mount it to the training instance.

Option B is correct because SageMaker Pipe input mode streams data directly from S3 to the training algorithm without writing to the instance's EBS volume, eliminating disk I/O bottlenecks. This is especially effective for large datasets (500 GB) that are updated daily, as it red…Read full explanation

Q2Data Engineeringhard
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A company uses Amazon Kinesis Data Streams to ingest real-time clickstream data from a website. The data is consumed by a Lambda function that writes records to an S3 bucket. Recently, the number of shards was increased from 2 to 4 to handle higher throughput. After the change, the Lambda function started processing records with increased latency and some records were being written out of order. What is the MOST likely cause?

AThe S3 bucket is not configured with versioning, causing overwrites.
BThe Lambda function is reading from the oldest sequence number, causing high IteratorAgeSeconds.
CThe Lambda function’s reserved concurrency is too low for the increased shard count.
The partition key used by the producer does not ensure that related records go to the same shard after resharding.Correct

Option D is correct because after resharding from 2 to 4 shards, the mapping of partition keys to shards changes. If the producer does not use a partition key that ensures related records (e.g., same user session) are routed to the same shard, records that were previously ordered…Read full explanation

Q3Data Engineeringeasy
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A data engineer needs to transform large CSV files stored in S3 into Parquet format and load them into a data warehouse for analysis. The transformation must be cost-effective and serverless. Which AWS service should be used?

AAmazon Athena
BAmazon EMR with Spark
AWS GlueCorrect
DAWS Data Pipeline

AWS Glue is the correct choice because it provides a fully managed, serverless ETL service that can automatically convert CSV files from S3 into Parquet format using its built-in Spark engine. It is cost-effective as you only pay for the resources consumed during the job executio…Read full explanation

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