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AWS Certified Data Engineer – Associate (DEA-C01) practice questions

100 questions in 10 tests. Open one to answer it on its own, or take a whole test.

Test 1

Take Test 1 ›
  1. A ride-hailing platform publishes trip telemetry to an Amazon Kinesis Data Streams stream running in provisioned mode with 20 shards. Producers set the partition key to the… · Data Ingestion and Transformation
  2. Connected vehicles publish telemetry to an Amazon Kinesis Data Streams stream. Each record carries the timestamp the device generated it. Because vehicles pass through tunnels… · Data Ingestion and Transformation
  3. A nightly AWS Glue Spark ETL job reads newline-delimited JSON files from s3://raw/events/ and appends the transformed rows to a curated Parquet table in Amazon S3. New files… · Data Ingestion and Transformation
  4. A nightly report on an Amazon Redshift RA3 cluster joins fact_orders (about 4 billion rows) to dim_customer (about 300 million rows) on customer_id. Both tables were created with… · Data Store Management
  5. A curated table in a data lake is already stored as Snappy-compressed Apache Parquet and is partitioned by event_date, with partitions registered in the AWS Glue Data Catalog. An… · Data Store Management
  6. Analysts need to run monthly SQL analysis over the full contents of a 2 TB Amazon DynamoDB orders table. The table serves a latency-sensitive checkout API in on-demand capacity… · Data Store Management
  7. A finance dashboard displayed negative order totals and rows with null customer identifiers. The bad records had already been loaded into the curated zone by an AWS Glue ETL job… · Data Operations and Support
  8. An AWS Lambda function consumes an Amazon Kinesis Data Streams stream through an event source mapping with a batch size of 500. Overnight, GetRecords.IteratorAgeMilliseconds for… · Data Operations and Support
  9. A data lake has grown to 40 AWS Glue databases and about 900 tables, organized informally into raw, curated, and restricted zones and into business domains such as sales and… · Data Security and Governance
  10. CSV extracts from dozens of upstream partners land in the raw zone of a data lake and are transformed by a single AWS Glue ETL job. Some extracts carry US Social Security numbers… · Data Security and Governance

Test 2

Take Test 2 ›
  1. An Amazon Data Firehose stream (named Amazon Kinesis Data Firehose in older material) receives JSON sensor readings and delivers them to Amazon S3, where analysts query them with… · Data Ingestion and Transformation
  2. A retailer runs a self-managed Apache Kafka cluster on Amazon EC2. Dozens of producer and consumer applications use the standard Kafka client libraries, and several teams run… · Data Ingestion and Transformation
  3. A nightly pipeline has two steps: an AWS Glue ETL job writes curated Parquet files, then an Amazon Redshift COPY loads them. Today, an AWS Lambda function calls StartJobRun and… · Data Ingestion and Transformation
  4. Business analysts run ad hoc Amazon Athena queries in a dedicated workgroup. A few times a month, someone runs a query with no partition filter against a multi-terabyte table… · Data Operations and Support
  5. A sales dashboard in a third-party BI tool runs the same query against Amazon Redshift every few minutes. The query joins a 3-billion-row sales fact table to two small dimension… · Data Operations and Support
  6. A data lake stores five years of customer interaction events as Parquet files in Amazon S3. The table is registered in the AWS Glue Data Catalog as a standard Hive-style table… · Data Store Management
  7. An order-management service stores orders in an Amazon DynamoDB table with partition key customer_id and sort key order_timestamp. The table has been in production for two years… · Data Store Management
  8. An AWS Glue crawler catalogs clickstream data under s3://lake/clickstream/, which is laid out as dt=YYYY-MM-DD/ folders. Every file is GZIP-compressed JSON. For months the… · Data Store Management
  9. A central data lake account (Account A) stores curated data in an Amazon S3 bucket. The bucket's default encryption is SSE-KMS with a customer managed key that Account A owns. An… · Data Security and Governance
  10. Auditors have asked a data engineering team to show which IAM principals read objects from the s3://finance-restricted/ bucket. An engineer opened CloudTrail Event history and… · Data Security and Governance

Test 3

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  1. An on-premises Oracle database backs a company's order-entry application. The analytics team needs a copy of the order tables in an Amazon S3 data lake that stays within a few… · Data Ingestion and Transformation
  2. An AWS Glue Spark job reads about 2 million JSON files per day from Amazon S3. Each file is roughly 20 KB. The job now runs for more than four hours on 30 G.1X workers. The Spark… · Data Ingestion and Transformation
  3. Partners upload CSV files to a single Amazon S3 prefix at unpredictable times, sometimes six files in an hour, sometimes none all afternoon. An hourly scheduled AWS Glue job… · Data Ingestion and Transformation
  4. A curated data lake zone holds 400 TB of Parquet. Access is genuinely unpredictable: a dataset may be queried heavily for three weeks while a model is being built, then ignored… · Data Store Management
  5. An Amazon Redshift cluster stores five years of fact_sales. Ninety-eight percent of queries touch only the last 90 days, but at quarter end a handful of analysts run… · Data Store Management
  6. An Athena table over application logs is partitioned by year, month, day, and hour, and has grown past 1.5 million partitions in the AWS Glue Data Catalog. Analysts report that… · Data Store Management
  7. A data platform team runs roughly 200 Apache Airflow DAGs on a pair of self-managed Amazon EC2 instances. They spend most of their on-call time patching the hosts, recovering a… · Data Operations and Support
  8. Twelve AWS Glue ETL jobs run between 01:00 and 04:00. When one of them fails, nobody finds out until an analyst reports a stale dashboard the next morning. The on-call engineer… · Data Operations and Support
  9. A security team needs a continuously updated picture of which of the roughly 900 Amazon S3 buckets across an AWS Organization are likely to contain sensitive data, so they can… · Data Security and Governance
  10. A customers table in Amazon Redshift contains a ssn column. Three groups query it through the same BI tool and the same table name: - fraud investigators must see the full value… · Data Security and Governance

Test 4

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  1. A retailer's clickstream flows into an Amazon Kinesis data stream in provisioned mode with 20 shards. Traffic is flat most of the year but multiplies during flash sales, when… · Data Ingestion and Transformation
  2. A nightly Spark batch runs on a long-lived Amazon EMR cluster of 1 primary and 40 core nodes, all On-Demand Instances. Finance wants the cluster's EC2 spend cut substantially… · Data Ingestion and Transformation
  3. Three applications already consume an Amazon Kinesis data stream using GetRecords. When a fourth consumer was added, all four began logging… · Data Ingestion and Transformation
  4. An Amazon DynamoDB table stores device telemetry events. Only the last 30 days of events are ever read; older items are dead weight, and the table's storage bill grows every… · Data Store Management
  5. A team is designing the S3 layout for an events table that will be queried through Amazon Athena. Roughly 12 million events arrive per day from about 4 million distinct… · Data Store Management
  6. A single Amazon Redshift RA3 provisioned cluster serves two workloads. Between 00:00 and 05:00 a heavy ETL load runs; during the same hours, BI dashboards used by an overseas… · Data Store Management
  7. An Amazon Redshift cluster has a WLM queue for ad-hoc analyst queries. Every few days someone submits a query with a missing join predicate; it runs for hours, and other… · Data Operations and Support
  8. An executive dashboard runs the same six Athena SELECT statements every time it is opened, which happens roughly 40 times a day. The underlying tables are refreshed once an hour… · Data Operations and Support
  9. An orders table is registered in the AWS Glue Data Catalog and queried through Amazon Athena. Three groups need different access to the same table: - EU analysts: only rows where… · Data Security and Governance
  10. A data lake bucket holds several hundred million small Parquet objects encrypted with SSE-KMS under a customer managed key. Since the analytics team scaled up its daily Athena… · Data Security and Governance

Test 5

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  1. An AWS Glue crawler has typed the order_total field of a JSON dataset as choice<double,string>, because a minority of upstream files emit the value quoted ("19.99") while the… · Data Ingestion and Transformation
  2. A Step Functions Standard workflow must call an AWS Lambda function once for each of roughly 4 million JSON objects under an Amazon S3 prefix. The current design reads the object… · Data Ingestion and Transformation
  3. A team runs a set of AWS Glue 4.0 Spark jobs on G.1X workers that reprocess historical data and refresh a pre-production environment. Nobody consumes the output until the… · Data Ingestion and Transformation
  4. An analytics team needs Salesforce opportunity records delivered to an Amazon S3 data lake once a day and registered in the AWS Glue Data Catalog. Nobody on the team has worked… · Data Ingestion and Transformation
  5. A new Amazon DynamoDB table will back a product launch. Nobody can forecast the request rate: it may be a few hundred requests per second or tens of thousands, and marketing will… · Data Store Management
  6. A nightly load writes one 200 GB gzip-compressed pipe-delimited file to Amazon S3 and loads it into an eight-node Amazon Redshift cluster with a single COPY statement. The load… · Data Store Management
  7. An Amazon Data Firehose stream applies an AWS Lambda transformation and converts records to Parquet before writing to Amazon S3. Analysts report that a small percentage of events… · Data Operations and Support
  8. A nightly COPY into an Amazon Redshift table aborts with: Load into table 'fact_events' failed. Check 'stl_load_errors' system table for details. The load reads 60 gzip files… · Data Operations and Support
  9. AWS Glue jobs and an Amazon EMR cluster run in private subnets and read and write tens of terabytes per month in Amazon S3 in the same Region. All of that traffic currently… · Data Security and Governance
  10. An AWS Glue job reads from an Amazon RDS for PostgreSQL database. The database password is currently hard-coded near the top of the job script, which is stored in Amazon S3 and… · Data Security and Governance

Test 6

Take Test 6 ›
  1. An AWS Glue streaming ETL job reads from an Amazon Kinesis data stream, enriches each record, and writes Parquet to Amazon S3. The job was stopped for a deployment and restarted… · Data Ingestion and Transformation
  2. A team wants to run Apache Kafka on AWS for an internal event bus. Traffic is bursty and hard to predict, the team has no Kafka operations experience, and nobody wants to size… · Data Ingestion and Transformation
  3. A data team runs about a dozen Apache Spark jobs a day on a long-running Amazon EMR cluster. Job sizes vary widely, so the cluster is often either over-provisioned and idle or… · Data Ingestion and Transformation
  4. Raw clickstream files land under s3://lake/raw/. Policy says they must stay immediately queryable for 30 days, be retained but rarely read for the following 11 months, and be… · Data Store Management
  5. A finance team's Amazon Redshift workload is concentrated into the first three business days of each month, when a dozen analysts run heavy SQL. For the rest of the month the… · Data Store Management
  6. A Redshift Spectrum external table maps to a Data Catalog table partitioned by country, category, and event_date, with about 900,000 partitions. Spectrum queries that filter on… · Data Store Management
  7. An AWS Glue Spark job reads a 34-million-row MySQL table with sparkSession.read.jdbc(url, tableName, connectionProperties) and writes it to Amazon S3 as Parquet. The job is… · Data Operations and Support
  8. An AWS DMS task is migrating an Oracle database to Amazon Aurora PostgreSQL with full load plus CDC. Before the cutover, the project lead must be able to demonstrate, row by row… · Data Operations and Support
  9. A team has adopted AWS Lake Formation on an account that already had AWS Glue Data Catalog databases and tables. A data lake administrator registered the S3 location and granted… · Data Security and Governance
  10. An audit found Athena query results written unencrypted to Amazon S3. Analysts query from the console, from a BI tool over JDBC, and from scripts that call the Athena API, and… · Data Security and Governance

Test 7

Take Test 7 ›
  1. A consumer application reads clickstream events from an Amazon Kinesis data stream that uses the default settings. A bug in the consumer corrupted its output. The team noticed… · Data Ingestion and Transformation
  2. Several teams publish JSON and Avro events to shared topics on Amazon MSK. Producers occasionally add required fields, which breaks downstream consumers that were built for the… · Data Ingestion and Transformation
  3. Business analysts receive raw CSV files in Amazon S3 with inconsistent date formats, missing values and misspelled category names. They do not write code. The team wants them to… · Data Ingestion and Transformation
  4. An Amazon Redshift fact table holds five years of sales rows. The rows were loaded per customer and backfilled over time, so they are not stored in date order. Nearly every… · Data Store Management
  5. An order-management system stores transactions in an Amazon Aurora MySQL cluster. Analysts need dashboards in Amazon Redshift that reflect new orders within seconds to minutes… · Data Store Management
  6. A retailer keeps its product catalog in Amazon DynamoDB, which serves key-based lookups well. The business now wants a search box that supports free-text queries over product… · Data Store Management
  7. A data engineer wants to be alerted when a consumer of an Amazon Kinesis data stream falls so far behind that unread records are at risk of expiring from the stream. Which… · Data Operations and Support
  8. A monthly purge job deletes about 40% of the rows from a very large Amazon Redshift table. Afterward, the table's storage use has not dropped and queries against it are slower… · Data Operations and Support
  9. A security policy states that all client connections to an Amazon Redshift cluster must be encrypted in transit. An audit shows that some legacy tools connect with SSL turned… · Data Security and Governance
  10. A producer account grants Lake Formation permissions on a Data Catalog table to a consumer account in the same AWS Organization. The consumer's data lake administrator can see… · Data Security and Governance

Test 8

Take Test 8 ›
  1. An Amazon Data Firehose stream delivers JSON events that contain a customer_id field to Amazon S3. The company has about 300 customers. Analysts query the data with Amazon Athena… · Data Ingestion and Transformation
  2. A nightly AWS Glue 4.0 Spark job runs with a fixed 60 G.2X workers. Input volume varies a lot from night to night, and CloudWatch shows that many stages use only a few executors… · Data Ingestion and Transformation
  3. A Kinesis data stream in account A uses server-side encryption with the AWS managed key for Kinesis. The team shares the stream with a consumer role in account B by using a… · Data Security and Governance
  4. Hourly change files from a source database land in Amazon S3. Each change record has a primary key and an operation type of insert, update or delete, and each hourly file… · Data Ingestion and Transformation
  5. A DynamoDB table has no backups configured. After a faulty deployment overwrote items, the team wants to be able to restore the table to its state at any second within the last… · Data Store Management
  6. Every weekday at 8 AM, hundreds of analysts open dashboards at once and queries queue on an Amazon Redshift RA3 cluster. For the rest of the day the cluster is lightly used. The… · Data Store Management
  7. A regulation requires that financial records stored in an Amazon S3 bucket cannot be deleted or overwritten by anyone, including the AWS account root user, for seven years. Which… · Data Store Management
  8. Application logs from several CloudWatch Logs log groups must be available in Amazon S3 within a few minutes so that analysts can query them with Athena. The team wants a managed… · Data Operations and Support
  9. A data engineer suspects that an AWS Glue Spark job is over-provisioned: it is billed for many workers, but the workload seems small. Which comparison of CloudWatch metrics shows… · Data Operations and Support
  10. Analysts use Amazon Quick dashboards to query data through Amazon Athena and Amazon Redshift. Today the dashboards connect with one shared IAM role, so data permissions apply to… · Data Security and Governance

Test 9

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  1. A retailer merges customer tables from two acquired companies. The same person often appears in both tables with different name spellings, partial addresses and missing fields… · Data Ingestion and Transformation
  2. An application publishes change events for several business entities into one stream. The data engineering team wants the events written directly to separate Apache Iceberg… · Data Ingestion and Transformation
  3. Clickstream events arrive in an Amazon Kinesis data stream. Analysts need the events queryable in Amazon Redshift within seconds, and the team does not want an Amazon S3 staging… · Data Ingestion and Transformation
  4. A payments company wants to detect fraud rings by finding accounts that are linked through shared devices, addresses and phone numbers, up to several hops away. The queries must… · Data Store Management
  5. A data lake holds 500 GB per day of JSON files in Amazon S3. Analysts run Athena queries that read only 3 of about 120 columns, and the query cost is high because each query… · Data Store Management
  6. A company keeps a data lake in Amazon S3 and must maintain a copy in a second Region for disaster recovery. Its compliance team requires that objects are replicated within a… · Data Store Management
  7. An account runs interactive Athena queries from many analysts and a set of month-end financial reporting queries in their own workgroup. During month-end, the reporting queries… · Data Operations and Support
  8. Several AWS Lambda functions that make up an ETL pipeline write logs to different CloudWatch Logs log groups. An engineer needs to find out quickly how many errors occurred per… · Data Operations and Support
  9. A team stores curated data in an Amazon S3 path and catalogs it in the AWS Glue Data Catalog. Under its governance model, analysts' IAM roles deliberately have no direct Amazon… · Data Security and Governance
  10. An Amazon Redshift cluster in account A must load data with COPY from an Amazon S3 bucket that belongs to account B. Security requires temporary credentials only, with no… · Data Security and Governance

Test 10

Take Test 10 ›
  1. A daily AWS Glue job processes only yesterday's data from a Data Catalog table that is partitioned by year, month and day. The table has grown to several years of data, and the… · Data Ingestion and Transformation
  2. External vendors upload daily files to an SFTP server that a company runs on an Amazon EC2 instance. The team must patch and scale the server, and wants a managed service that… · Data Ingestion and Transformation
  3. A data engineer creates an AWS Step Functions state machine as an Express workflow to save cost. One state runs an Amazon Athena CTAS query with the startQueryExecution.sync… · Data Ingestion and Transformation
  4. A DynamoDB-backed application serves users in two AWS Regions. Users in both Regions need fast local reads and writes against the same data, and the business wants the… · Data Store Management
  5. A machine learning training job reads millions of small objects with a random access pattern, and GPU instances sit idle while they wait for data from Amazon S3. The team needs… · Data Store Management
  6. A team runs transient Amazon EMR clusters that are created for each job and terminated afterward. Hive table definitions created on one cluster are lost when it terminates, and… · Data Store Management
  7. An AWS Glue ETL job uses a Glue connection to read from an Amazon RDS database in a private subnet. The job fails because it cannot connect to the database. The database's… · Data Operations and Support
  8. A data engineer investigates a slow Amazon Redshift query. In STL_ALERT_EVENT_LOG, the query has an alert titled "Nested Loop Join in the query plan". What is the recommended… · Data Operations and Support
  9. A compliance policy requires that all access to the objects in an Amazon S3 data lake bucket use encrypted connections. Some older applications still call the bucket over plain… · Data Security and Governance
  10. A data lake bucket in Amazon S3 is shared by 40 teams, and each team must read and write only its own prefixes. Some teams must also be restricted so that their requests come… · Data Security and Governance