Amazon DEA-C01 Exam Prep
AWS Certified Data Engineer - Associate DEA-C01 (Page 19 )

• Amazon EMR is the best fit because it provides managed clusters that can run the same big-data frameworks you already use on-premises (e.g., Pig, Oozie, Apache Spark, Apache HBase, Apache Flink). This lets you migrate to AWS with similar performance characteristics while reducing operational overhead.
• EMR offers on-demand, scalable clusters and can be integrated with serverless-like patterns (for example, via EMR on EKS or Step Functions) to minimize ongoing maintenance.
• Why not Glue or Lambda?

• Workspace: Stores notebooks, libraries, jobs, and other project resources.
• Notebooks: Interactive documents containing code, queries, visualizations, and explanations. Common languages include Python, SQL, Scala, and R.
• Clusters: Groups of virtual machines that run Spark workloads. Clusters can be started, stopped, and automatically scaled.
• Data access: Databricks can read from services such as Azure Data Lake Storage, Azure Blob Storage, and Azure SQL.
• Jobs: Automate notebooks or data-processing workflows on a schedule or in response to events.

• Elicited and documented customer requirements
• Converted them into clear, measurable specifications
• Validated the requirements with the customer
• Used them as the basis for design, quality checks, and acceptance

• A: Requirements should reflect the customer’s needs—not the supplier’s standards.
• B: Iteration review planning does not replace proper requirements collection.
• D: A retrospective occurs after work is completed and is mainly for process improvement, not initial requirements definition.

• Business
• People
• Governance
• Platform
• Security
• Operations

• Cloud financial management
• Portfolio management
• Data governance
• Risk management
• Compliance

• Input feature distributions differ from training data ? Analyze dataset drift metrics

• Model accuracy drops without code changes ? Analyze dataset drift metrics

• Endpoint latency increases under load ? Investigate scaling and infrastructure metrics

• Wiping securely overwrites the drive so the original data cannot reasonably be recovered. It is generally less expensive than physically destroying the device.
• Recycling could expose the data if the drive is not securely erased first.
• Shredding physically destroys the drive and is effective, but usually more costly and prevents reuse.
• Deletion only removes file references; it is not a secure sanitization method.

• C series: CPU-optimized instances; not designed primarily for LLM training.
• G series: GPU instances generally optimized for graphics and some machine learning workloads, but not specifically large-scale model training efficiency.
• P series: Powerful GPU instances for ML training, but typically consume more energy than Trainium-based instances for suitable training workloads.

• B — Prompts and suggestions retained for 28 days
• C — User engagement data kept for two years

• The key distinction is between content data—your prompts, code context, and generated suggestions—and engagement data, such as usage activity.
• Do not confuse retention with training: enterprise Copilot data is generally not used to train GitHub’s models without appropriate authorization.
• For a current exam, verify the policy version cited by the exam provider. The key’s C is likely correct, but B should be treated cautiously and may no longer reflect the current policy.

• Basic: Self-help only; no technical support or design assessment.
• Standard: Technical support, but not the full proactive architectural guidance required here.
• Professional Direct: Provides proactive guidance and architecture-related assistance.
• Premier: Also supports this, but is a more expensive, enterprise-level option.

• Geo-redundant storage (GRS) replicates data to a secondary Azure region, but the secondary copy is normally unavailable for read access.
• RA-GRS provides geo-replication and read-only access to the secondary region, satisfying all requirements.
• Zone-redundant storage (ZRS) replicates data across availability zones within the same Azure region, not separate geographic regions.
• Locally redundant storage (LRS) keeps copies within a single datacenter or region and does not provide geographic resiliency.

• Conserve public IPv4 addresses: IPv4 addresses are limited, so many internal devices share a smaller number of public addresses through NAT.
• Reduce direct exposure: Private addresses are not directly routable from the public Internet, which helps reduce unsolicited access to internal devices.

Flat organisation

• Few levels of management
• A wide span of control—managers supervise many employees
• Shorter communication channels
• More employee autonomy and quicker decisions
• Fewer formal promotion levels

Tall organisation

• Many levels of management
• A narrow span of control—managers supervise relatively few employees
• A clear hierarchy and reporting structure
• More formal supervision and communication channels
• More obvious promotion and career stages

• 6-phone boxes: 6x
• 8-phone boxes: 8x

sql 
CREATE TABLE my_table 
USING CSV 
OPTIONS (path '/path/to/csv');

sql 
CREATE TABLE my_table 
USING CSV 
LOCATION '/path/to/csv';

• USING CSV specifies the file format.
• path or LOCATION specifies where the files are stored.
• USING DELTA would be used only when the source data is in Delta format.
• FROM is used in a SELECT statement, not normally as the format declaration in CREATE TABLE.

• Tactics: The attacker’s overall goal, such as gaining persistence or exfiltrating data
• Techniques: The methods used to achieve that goal
• Procedures: The specific implementation or sequence of actions

• IP addresses and hash values: Useful indicators, but they can change quickly.
• Indicators of compromise: TTPs may help identify IOCs, but their main value is describing behavior.
• Tools: Attackers can replace tools or use legitimate administrative utilities.

• Multiple nodes: Data is replicated several times in the primary region.
• Separate geography: A copy is asynchronously replicated to a secondary Azure region.
• Readable secondary: RA-GRS provides read-only access to the secondary replica, even when the primary region is available.

• GRS: Replicates to another region but the secondary copy isn’t normally readable.
• ZRS: Replicates across availability zones in the same region, not a separate geographic region.
• LRS: Keeps replicas within a single datacenter or region and provides no geographic redundancy.

• AWS Budgets lets you create a cost or usage budget and configure alerts when actual or forecasted spending reaches a threshold. Notifications can be sent through email or Amazon SNS.
• Amazon CloudWatch can monitor AWS billing metrics and trigger an alarm when estimated charges exceed a specified amount.

• Amazon SQS is a message queue, not a cost-monitoring service.
• Cost Explorer analyzes spending but does not directly provide threshold notifications.
• AWS Cost and Usage Report delivers detailed billing data for analysis; it does not itself send threshold alerts.

• Internal interface ? connected toward the corporate network/internal firewall
• External interface ? connected toward the Internet-facing firewall

1. A route for the internal corporate network through the internal-facing interface/firewall.
2. A default route (0.0.0.0/0) through the Internet-facing interface/firewall.

• Which Security policy matches
• Which NAT rule/translation is selected
• Which PBF rule applies
• Which route is used

text 
test security-policy-match ... 
test nat-policy-match ... 
test pbf-policy-match ... 
test routing fib-lookup ...

• Aggregation happens once, during the scheduled job.
• Dashboard users query a relatively small, precomputed table.
• Repeated users do not trigger expensive aggregations against the detailed sales table.
• Overwriting is appropriate because the summary is rebuilt for the reporting period.

• B: Structured Streaming is unnecessary for data that only needs daily refreshes and adds operational/compute overhead.
• C: A view recomputes the aggregation at query time, increasing latency and query cost.
• D: Delta caching may improve reads but does not replace the need to materialize the expensive aggregation, and cache availability is not the main design guarantee.

• C — “when the query finishes”

• D — “when the query began”

Question 3: AWS Storage Gateway File Gateway

• A: S3 bucket per user — S3 is object storage, not a traditional shared file system; mounting it requires extra tools and is less efficient.
• B: File Gateway — Provides a local file share using standard file protocols while storing files in Amazon S3. This preserves convenient local access and extends storage capacity.
• C: WorkSpaces and WorkDocs — Designed for virtual desktops and document collaboration, not large shared file storage.
• D: EC2 with EBS — EBS is attached to one EC2 instance and is not designed for direct multi-user file sharing.

• Import: Copies data into the Power BI model. It requires scheduled or manual refresh, so it may not meet the two-minute requirement.
• Live connection: Connects to an existing Power BI semantic model or Analysis Services model; it is not the appropriate choice for connecting directly to the Azure SQL database in this scenario.

• Customer contains one row per customer and the customer’s Address ID.
• Address contains one row per address and the corresponding location details.

1. Select the Customer query.
2. Choose Merge Queries.
3. Match Customer[Address ID] with Address[Address ID].
4. Use a Left outer join so every customer is retained.
5. Expand the merged Address column and select City, State/Region, and Country.

• Append adds rows vertically and is used for tables with the same structure.
• Group By summarizes rows rather than adding related columns.
• Transpose switches rows and columns and does not establish a relationship.

• The identified risk
• Its likelihood and potential impact
• The person or team responsible for handling it
• The response or treatment plan
• Risk thresholds, such as when escalation or action is required
• Current status and review dates

• Risk tolerance: The amount of risk an organization is willing to accept; it is a concept or limit, not usually the primary documentation.
• Risk transfer: Moving the responsibility or financial impact of a risk to another party, such as through insurance.
• Risk analysis: The process of evaluating risk likelihood and impact.

• Azure Resource Manager (ARM) templates define Azure resources in a declarative JSON file.
• You can deploy the same template repeatedly for each business unit, ensuring that identical resources are created consistently.
• Templates reduce manual administrative effort and support repeatable, automated deployments.
• Parameters can customize values such as names, regions, and sizes while keeping the overall resource configuration the same.

• tag=Priv searches the tag field for values beginning with Priv. The wildcard can match the remaining characters, so it matches Privileged.
• tag=Priv would search for the exact tag Priv, not Privileged.
• tag=priv* uses lowercase priv; tag matching is treated as case-sensitive here, so it may not match the tag Privileged.
• tag=privileged uses the wrong capitalization for the exact tag.

• A. Tuning system software: This is a corrective action, not an analysis method. Tuning should be based on measured performance data.
• B. User dissatisfaction reports: Useful as an indicator, but subjective and insufficient for diagnosing the cause.
• D. Off-peak utilization and response time: This may hide problems occurring during peak periods. Performance analysis should cover representative or peak workloads.

• The explanation states that Traffic Analytics can be enabled by a user with one of these subscription-level roles:

• Question 34 — Network Contributor: Yes
• Question 35 — Owner: Yes
• Question 36 — Reader: Yes, according to the stated explanation and documentation

• ADF: Automatic Document Feeder; a printer/scanner hardware component.
• USB: A short-range wired connection, not a protocol for accessing a remote shared folder.
• PCL: Printer Control Language; it describes how print jobs are formatted, not how files or printers are shared over a network.

• principal represents the source or initiating system.
• principal.port is the source port.
• target represents the destination system.
• target.port is the destination port.

text 
principal.port = 5555

• network.ApplicationProtocol = HTTP identifies HTTP traffic but not the backdoor specifically.
• target.port = 5555 finds traffic going to port 5555, rather than originating from it.
• network.ip_protocol = TCP is too broad because many services use TCP.

• Equipment and hardware
• Facilities
• Inventory
• Backup media
• Supplies stored at an alternate or remote location

• Personal belongings of staff: Usually not organizational assets.
• DR line-item revenues: Revenue is a financial impact, not a physical asset.
• Cloud-based applications: These are primarily logical or information-processing assets, even though they depend on physical infrastructure.

1. Modify the database subnet NACL inbound rules to allow traffic from the new web subnet’s CIDR block on the MySQL port (3306).
2. Modify the database subnet NACL outbound rules to allow return traffic to the new web subnet’s CIDR block on the required ephemeral port range.

Simple explanation

• The Azure VPN gateway to connect to
• Authentication settings
• Routes for networks that the client can access

• Detect risky sign-ins from unfamiliar or unidentified IP addresses
• Evaluate user or sign-in risk
• Automatically require a password change because of a risky sign-in

• User risk policy: Can require a user to securely change their password when the account may be compromised.
• Sign-in risk policy: Can require MFA or block access based on the risk of a particular sign-in.

• Matching hashes: The software is unchanged.
• Different hashes: The software was modified or corrupted.

• Encryption: Protects confidentiality.
• Baselines: Define approved configurations or normal performance.
• Tokenization: Replaces sensitive data with tokens.

• ARP poisoning: Redirects or intercepts local network traffic; it would more likely affect communication paths or cause man-in-the-middle behavior.
• Jamming: Interferes with wireless signals. The scenario does not indicate a wireless outage.
• Kerberoasting: Attempts to obtain service-account password hashes from Kerberos; it is a credential attack, not typically a direct service outage.

• Creating and managing users and roles
• Granting and revoking roles and privileges
• Managing access-control responsibilities

• SYSADMIN: Manages warehouses, databases, schemas, and other objects—not primarily users and roles.
• PUBLIC: Automatically granted to every user; it is not an administrative role.
• ACCOUNTADMIN: Has the highest level of access, but should be reserved for account-level administration and emergencies rather than routine security tasks.

• Users logging in more frequently than average
• Logins occurring during non-business hours
• Patterns that may indicate compromised credentials or suspicious access

• Login History: Shows individual login attempts and basic details, but does not provide behavioral analysis or averages.
• Login Inspector: Used to troubleshoot or inspect a specific login attempt, rather than analyze organization-wide patterns.
• Login Report: May provide reportable login information, but it is not the specialized tool for forensic behavioral analysis.

• Digitally signing the software: Verifies authenticity and integrity. It does not hide how the software works.
• Limiting third-party libraries: May reduce dependencies and attack surface, but does not directly prevent reverse engineering.
• Using compile flags: Some compiler options can remove debugging information or optimize code, which may provide limited protection, but this is not the primary technique identified for preventing reverse engineering.

• A valid input returns the expected result
• An invalid input raises an error
• Boundary values are handled correctly

• B: Copilot may help generate tests, but it does not automatically write all necessary tests.
• C: Writing the implementation does not verify that it works correctly.
• D: Copilot can suggest test commands or test code, but the developer or development environment must execute and validate the tests.

• The inference container image or built-in algorithm
• The location of model artifacts in Amazon S3
• IAM permissions through the execution role
• Optional environment variables and networking settings

1. Create AWS::SageMaker::Model
2. Create an AWS::SageMaker::EndpointConfig that references the model
3. Create AWS::SageMaker::Endpoint that references the endpoint configuration

• AWS::SageMaker::Endpoint hosts a model but does not define the model itself.
• AWS::SageMaker::NotebookInstance provides a development environment.
• AWS::SageMaker::Pipeline orchestrates ML workflow steps.

• A. Number ? Decimal — Correct. Salesforce Number fields are represented in Apex as Decimal.
• D. Date/Time ? Datetime — This is correct conceptually, but “Dateline” is not an Apex type. If the option literally says “Dateline,” it is incorrect.
• E. Checkbox ? Boolean — Correct. A checkbox contains true or false.

• Number ? Integer — A Number field maps to Decimal, even when its scale is zero.
• Text Area ? List<String> — A text area maps to a single String, not a list.

• Cloud architecture
• Data architecture
• Platform engineering
• Data engineering
• Provisioning and modernization

• Data protection is associated mainly with security and risk management.
• Data governance belongs to the governance perspective.
• Data science is not an AWS CAF capability.

• Vertical scaling (scale up) means increasing the size of an existing VM—for example, adding CPU or RAM.
• Vertical scaling down means reducing the VM’s size when less capacity is needed.
• Horizontal scaling (scale out) means adding more VM instances rather than making one VM larger.
• Elasticity is the broader ability to automatically adjust resources based on demand; it does not specifically mean adding CPU or memory to one VM.
• Agility refers to the ability to provision or change resources quickly.

1. You try to access a cloud application, such as accounting software.
2. The application redirects you to the company’s IdP.
3. You authenticate with the IdP.
4. The IdP sends a digitally signed SAML assertion to the application.
5. The application validates the assertion and grants access.

• The user’s identity
• Whether authentication succeeded
• Roles or group membership
• Access-related attributes

• Confirm the required columns and data types
• Identify the target/label column
• Handle missing or duplicate records if present
• Transform data into a suitable format
• Split it into training and validation/test datasets

1. Prepare the training data
2. Select an algorithm or configure AutoML
3. Train the model
4. Evaluate its performance
5. Tune hyperparameters if needed
6. Deploy the model

• Scheduling overlapping working hours for critical collaboration
• Assigning independent tasks that can proceed asynchronously
• Adding clear handoffs between offices
• Documenting decisions, questions, and required inputs
• Building appropriate time into the schedule for responses