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CCNA Deployment and Migration Questions

75 of 341 questions · Page 4/5 · Deployment and Migration · Answers revealed

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226
MCQmedium

A company is deploying a multi-AZ Aurora MySQL database. They need to ensure that failover happens automatically with minimal data loss. Which configuration should be used?

A.Deploy an Aurora Global Database with a primary in one region and a secondary in another region.
B.Use a Multi-AZ RDS for MySQL deployment.
C.Create an Aurora cluster with one primary and two readers in different Availability Zones.
D.Configure a single-AZ Aurora instance and enable cross-Region replication.
AnswerC

Aurora automatically fails over to a reader with minimal data loss.

Why this answer

An Aurora cluster with one primary and two readers in different Availability Zones provides automatic failover with minimal data loss. Aurora uses a shared cluster volume that is replicated six ways across three AZs, ensuring that during a failover, the promoted reader has access to all committed transactions with no data loss. This configuration meets the requirement for multi-AZ high availability and automatic failover within a single region.

Exam trap

The trap here is that candidates often confuse Multi-AZ RDS for MySQL with Aurora's multi-AZ architecture, not realizing that Aurora's distributed storage and reader promotion provide superior automatic failover with minimal data loss compared to traditional RDS Multi-AZ.

How to eliminate wrong answers

Option A is wrong because an Aurora Global Database is designed for cross-region disaster recovery, not for automatic failover within a single region; it introduces replication lag of up to 1 second, which can result in data loss during a failover. Option B is wrong because Multi-AZ RDS for MySQL uses synchronous replication to a standby instance, but it is not Aurora and does not leverage Aurora's distributed storage engine, which provides faster failover and better durability. Option D is wrong because a single-AZ Aurora instance with cross-Region replication does not provide automatic failover within the same region; it only replicates asynchronously to another region, and a failure in the primary AZ would cause downtime until manual intervention.

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227
MCQhard

A company is using an Amazon RDS for SQL Server database with Multi-AZ deployment. They need to migrate to Amazon RDS for SQL Server in a different AWS region. The database is 1 TB and cannot tolerate more than 15 minutes of downtime. Which strategy minimizes downtime?

A.Create a cross-region read replica in the target region and promote it to a standalone instance.
B.Take a snapshot of the source RDS instance and restore it in the target region. Then update the application connection string.
C.Set up cross-region replication using native SQL Server log shipping or DMS with ongoing replication, then perform a DNS cutover to the target instance.
D.Use AWS DMS to perform a full load to a new RDS instance in the target region. During the final sync, stop the source and resume from the target.
AnswerC

This approach keeps the target synchronized and allows a quick cutover with minimal downtime.

Why this answer

It combines native SQL Server log shipping or AWS DMS with ongoing replication to keep the target region instance nearly synchronized with the source, enabling a DNS cutover with minimal downtime. This approach meets the 15-minute downtime requirement by allowing a controlled final sync and cutover, unlike snapshot restore or full-load-only methods that require longer outages. Multi-AZ deployment does not prevent cross-region replication, and log shipping or DMS can handle the 1 TB database within the downtime window if properly configured.

Exam trap

The trap here is that candidates often assume cross-region read replicas are available for all RDS engines, but SQL Server does not support them, leading them to choose Option A without verifying engine-specific limitations.

How to eliminate wrong answers

Option A is wrong because Amazon RDS for SQL Server does not support cross-region read replicas; read replicas are only available within the same region for SQL Server, and promoting a replica that cannot be created across regions is not feasible. Option B is wrong because taking a snapshot and restoring it in the target region requires the source to be stopped or at least incur significant downtime during the snapshot creation and restore process, which for a 1 TB database would exceed 15 minutes. Option D is wrong because using AWS DMS for a full load only, without ongoing replication, means the target database will be out of sync with the source during the final sync, requiring a longer outage to capture and apply changes, which cannot guarantee the 15-minute downtime limit.

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228
MCQmedium

A company is deploying a MySQL RDS instance using this CloudFormation template. After deployment, they notice that the database is not automatically backed up at the scheduled time. What is the most likely cause?

A.The storage type gp2 does not support automated backups.
B.The PreferredBackupWindow is not defined, so backups are disabled.
C.MultiAZ is enabled, which disables automated backups.
D.The BackupRetentionPeriod must be greater than 0 to enable automated backups; however, it is set to 7, so this is not the issue. The actual cause might be that the DB instance is using a storage engine not supported for backups (e.g., MyISAM).
AnswerD

RDS automated backups require InnoDB; MyISAM tables cause backup failure.

Why this answer

The BackupRetentionPeriod is set to 7, which is greater than 0, so automated backups are enabled. However, the most likely cause of the backup failure is that the DB instance is using a storage engine like MyISAM, which does not support point-in-time recovery or consistent automated backups in Amazon RDS. RDS automated backups rely on the InnoDB storage engine for crash recovery and transaction consistency; MyISAM tables can cause backup failures or incomplete backups.

Exam trap

The trap here is that candidates focus on the BackupRetentionPeriod being set to 7 (which is correct) and overlook the storage engine limitation, assuming all MySQL storage engines are equally supported for automated backups in RDS.

How to eliminate wrong answers

Option A is wrong because gp2 storage type fully supports automated backups; automated backups are supported on all storage types (gp2, gp3, io1, io2, magnetic) as long as the BackupRetentionPeriod is greater than 0. Option B is wrong because the PreferredBackupWindow is optional; if not defined, AWS automatically assigns a random backup window, it does not disable backups. Option C is wrong because MultiAZ does not disable automated backups; in fact, MultiAZ deployments still support automated backups and the backup window is used to take backups from the standby instance to reduce I/O impact.

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229
MCQhard

A company is migrating a 5 TB MySQL database to Amazon Aurora MySQL. The migration must have zero downtime and the source database is continuously written to. The team plans to use AWS DMS with ongoing replication. However, they notice that the target Aurora instance is not receiving all changes from the source. Which configuration change is most likely required to resolve this?

A.Create an Amazon RDS read replica of the source database and use it as the source endpoint.
B.Set the target table preparation mode to 'Do nothing' in the DMS task.
C.Enable binary logging (binlog) on the source MySQL database with row-based logging.
D.Configure a VPC endpoint for the DMS replication instance.
AnswerC

DMS needs binlogs for ongoing replication; if not enabled, it cannot capture changes.

Why this answer

AWS DMS requires binary logging (binlog) with row-based logging on the source MySQL database to capture ongoing changes for continuous replication. Without binlog enabled, DMS cannot read the change data stream needed to replicate transactions to the target Aurora instance, causing missed changes. This is a mandatory prerequisite for any MySQL-to-Aurora migration using DMS with ongoing replication.

Exam trap

The trap here is that candidates may overlook the fundamental prerequisite of binary logging for DMS ongoing replication and instead focus on network connectivity (VPC endpoints) or task configuration settings that do not address the root cause of missing change capture.

How to eliminate wrong answers

Option A is wrong because creating an RDS read replica does not enable the binary logging needed for DMS to capture ongoing changes; the read replica itself would still lack binlog unless explicitly enabled, and it adds unnecessary complexity. Option B is wrong because setting the target table preparation mode to 'Do nothing' only affects how DMS handles existing tables on the target during full load, not the capture of ongoing changes from the source. Option D is wrong because a VPC endpoint is used for private connectivity between services within a VPC, but it does not enable or affect the binary logging configuration required for change data capture.

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230
MCQhard

Refer to the exhibit. A company's production RDS MySQL instance 'mydb' is configured as shown. The application experiences write latency spikes during peak hours. Which action would most effectively reduce write latency?

A.Change the storage type to Provisioned IOPS (io1) and allocate sufficient IOPS.
B.Create a Read Replica in a different region.
C.Increase the allocated storage to 1 TB to improve baseline IOPS.
D.Enable Multi-AZ deployment to provide a standby instance.
AnswerA

Provisioned IOPS provides consistent, low-latency write performance.

Why this answer

The RDS MySQL instance uses gp2 storage with 500 GB, providing a baseline of 1500 IOPS (3 IOPS per GB). Write latency spikes during peak hours indicate that the workload is exceeding these IOPS, causing throttling. Changing to Provisioned IOPS (io1) allows allocating a higher, consistent IOPS level that matches the write workload, directly reducing write latency.

Option D (Multi-AZ) adds synchronous replication overhead, increasing write latency. Option B (Read Replica) offloads reads, not writes. Option C (increasing storage) raises baseline IOPS but is less efficient and more costly than provisioning exact IOPS with io1.

Exam trap

Multi-AZ improves availability but adds synchronous replication to the standby, which increases write latency. Candidates may incorrectly think Multi-AZ reduces write latency.

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231
Multi-Selectmedium

A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. Which TWO AWS services can be used to assess the source database for compatibility and migration readiness?

Select 2 answers
A.Amazon Kinesis
B.AWS Schema Conversion Tool (SCT)
C.AWS Database Migration Service (DMS)
D.AWS Glue
E.Amazon CloudWatch
AnswersB, C

SCT assesses and converts schema.

Why this answer

AWS Schema Conversion Tool (SCT) is designed to assess source databases for compatibility by analyzing the schema, code objects, and dependencies, then generating a detailed assessment report that identifies conversion complexity and migration readiness. For PostgreSQL to Amazon RDS for PostgreSQL migrations, SCT validates that the source schema is compatible with the target RDS engine version and highlights any deprecated features or required modifications.

Exam trap

The trap here is that candidates confuse AWS DMS (which handles data migration and can perform some schema conversion via its built-in transformation rules) with the assessment and schema conversion capabilities of SCT, but DMS alone does not provide a detailed compatibility assessment report or code-level conversion analysis.

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232
Multi-Selectmedium

A company is migrating a 500 GB SQL Server database to Amazon RDS for SQL Server. The migration must minimize downtime and support ongoing replication. Which TWO AWS services should be used together?

Select 2 answers
A.AWS Lambda
B.AWS Snowball Edge
C.AWS RDS SQL Server native backup and restore
D.AWS Database Migration Service (DMS)
E.AWS Schema Conversion Tool (SCT)
AnswersD, E

DMS supports ongoing replication with change data capture.

Why this answer

AWS Database Migration Service (DMS) is the correct choice because it supports ongoing replication (change data capture) from a source SQL Server database to Amazon RDS for SQL Server with minimal downtime. DMS can perform a full load followed by continuous replication of changes, allowing the source to remain operational during migration.

Exam trap

The DBS-C01 exam often tests the misconception that native backup and restore (Option C) is sufficient for minimal-downtime migrations, but it requires a full outage for the final restore, whereas DMS with ongoing replication allows near-zero downtime.

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233
Multi-Selectmedium

Which THREE factors should be considered when choosing between Amazon RDS and Amazon DynamoDB for a new application? (Choose THREE.)

Select 3 answers
A.The requirement for encryption at rest.
B.The need for multi-AZ high availability.
C.The query patterns and access methods required by the application.
D.The need for complex transactions and joins.
E.The expected scalability and throughput requirements.
AnswersC, D, E

RDS supports SQL queries, while DynamoDB is NoSQL with key-value and document queries.

Why this answer

The choice between Amazon RDS (relational) and DynamoDB (NoSQL) hinges on the application's data access patterns. RDS supports complex SQL queries with joins, aggregations, and secondary indexes, while DynamoDB is optimized for key-value and document queries with predictable, low-latency access patterns. If the application requires flexible querying with ad-hoc filters, RDS is appropriate; if it needs high-throughput, single-key lookups or simple query patterns, DynamoDB is better suited.

Exam trap

The trap here is that candidates assume encryption at rest or multi-AZ HA are exclusive to one service, but both RDS and DynamoDB fully support these features, making them irrelevant for choosing between the two.

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234
MCQmedium

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. The database has a large table with a BLOB column storing PDF files. Which migration approach minimizes downtime?

A.Use Oracle Data Pump to export the table and import into RDS.
B.Use Oracle RMAN to back up the database and restore to RDS.
C.Export the table without the BLOB column, then import the BLOBs separately.
D.Use AWS Database Migration Service (DMS) with ongoing replication.
AnswerD

DMS can perform a full load and then continuously replicate changes to minimize downtime.

Why this answer

AWS DMS with ongoing replication (change data capture) allows you to perform an initial full load of the database while continuously capturing and applying changes from the source Oracle database to the target RDS for Oracle instance. This minimizes downtime because you can cut over to the new database after the initial load and replication lag is near zero, rather than taking the source offline for the entire migration.

Exam trap

The trap here is that candidates often assume traditional Oracle tools like Data Pump or RMAN are the best for minimizing downtime, but they fail to recognize that AWS DMS with ongoing replication is specifically designed for near-zero downtime migrations by continuously synchronizing changes.

How to eliminate wrong answers

Option A is wrong because Oracle Data Pump is a logical export/import tool that requires the source database to be in a consistent state during export, and it does not support ongoing replication, so the database must be taken offline for the entire duration of the export and import. Option B is wrong because RMAN backups are physical backups that cannot be directly restored to Amazon RDS for Oracle, as RDS does not provide access to the underlying file system or allow RMAN restore operations. Option C is wrong because exporting the table without the BLOB column and then importing the BLOBs separately introduces complexity and still requires a period of downtime to ensure consistency between the table and the BLOB data, and it does not provide ongoing replication to minimize cutover time.

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235
MCQmedium

A company is deploying a new web application that requires a highly available MariaDB database. The application is read-heavy and needs to scale read traffic. Which deployment approach meets these requirements?

A.Deploy Amazon Aurora MySQL with a read replica.
B.Deploy a Multi-AZ RDS for MariaDB with one or more read replicas.
C.Deploy a Multi-AZ RDS for MariaDB instance.
D.Deploy a single-AZ RDS for MariaDB with a read replica.
AnswerB

Combines HA and read scaling.

Why this answer

Deploying a Multi-AZ RDS for MariaDB provides high availability through automatic failover to a standby in a different Availability Zone, while adding one or more read replicas offloads read traffic from the primary instance, meeting the read-heavy scaling requirement. This combination ensures both fault tolerance and read scalability for a MariaDB database.

Exam trap

The trap here is that candidates often confuse Amazon Aurora MySQL with MariaDB, or assume that Multi-AZ alone provides read scaling, when in fact read replicas are required for read-heavy workloads.

How to eliminate wrong answers

Option A is wrong because Amazon Aurora MySQL is not MariaDB; it uses a MySQL-compatible engine but is not the same as MariaDB, and the question explicitly requires a MariaDB database. Option C is wrong because a Multi-AZ RDS for MariaDB instance alone provides high availability but does not scale read traffic; read replicas are needed to handle read-heavy workloads. Option D is wrong because a single-AZ RDS for MariaDB with a read replica can scale reads but lacks high availability, as a failure in the primary instance's Availability Zone would cause downtime until manual recovery or a read replica promotion.

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236
MCQeasy

A developer is connecting to an RDS for MySQL instance. What is the endpoint address that should be used in the database connection string?

A.mydb
B.mydb.123456789012.us-east-1.rds.amazonaws.com
C.3306
D.Z1R2S3V4X5Y6Z7
AnswerB

This is the DNS endpoint address.

Why this answer

When connecting to an Amazon RDS for MySQL instance, the endpoint is a fully qualified domain name (FQDN) that resolves to the underlying database host. Option B provides the correct FQDN format: a DB instance identifier followed by a randomly generated alphanumeric string, the AWS region, and the rds.amazonaws.com domain. This endpoint is found in the RDS console under the instance's 'Connectivity & security' tab and is required by MySQL clients to establish a TCP connection.

Exam trap

The trap here is that candidates confuse the DB instance identifier (a simple name like 'mydb') with the full endpoint, or they mistake the port number (3306) for the address, because MySQL connection strings often list the host and port together, leading to the misconception that the port is part of the endpoint.

How to eliminate wrong answers

Option A is wrong because 'mydb' is only the DB instance identifier, not the full endpoint; a MySQL client cannot resolve a bare name to an RDS host without the full FQDN. Option C is wrong because 3306 is the default MySQL port number, not an endpoint address; the port is specified separately in the connection string (e.g., after a colon). Option D is wrong because 'Z1R2S3V4X5Y6Z7' resembles a DNS resolver ID or a random string, not the RDS endpoint format which always includes the region and 'rds.amazonaws.com'.

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237
MCQmedium

A company is migrating a self-hosted MongoDB database to Amazon DocumentDB. They need to ensure that indexes are created after the data load to improve migration performance. Which migration strategy should they use?

A.Use AWS Schema Conversion Tool (SCT) to convert the schema and then load data with DMS.
B.Use AWS DMS with 'create indexes before data load' option enabled.
C.Use AWS Database Migration Service (DMS) with the 'lob' mode set to 'Don't include LOB columns' and create indexes after the full load.
D.Use mongodump and mongorestore with the --writeConcern option set to 0.
AnswerC

Deferring index creation speeds up data migration; DMS can handle data transfer.

Why this answer

AWS DMS can be configured to skip LOB columns during the full load, which significantly improves migration performance by reducing data transfer overhead. After the full load completes, indexes can be created on the target DocumentDB database, avoiding the performance penalty of maintaining indexes during the bulk data ingestion. This approach aligns with the requirement to defer index creation until after the data load.

Exam trap

The trap here is that candidates may assume DMS has a built-in option to defer index creation (like some relational database migration tools), but DMS for DocumentDB requires manually configuring LOB handling and creating indexes post-load, and they might confuse the 'create indexes before data load' misconception with a real DMS feature.

How to eliminate wrong answers

Option A is wrong because AWS Schema Conversion Tool (SCT) is used for schema conversion of relational databases, not for MongoDB to DocumentDB migrations, and it does not control index creation timing during data load. Option B is wrong because DMS does not have a 'create indexes before data load' option; in fact, creating indexes before loading data would degrade migration performance due to index maintenance overhead during the load. Option D is wrong because mongodump and mongorestore are native MongoDB tools, not AWS DMS, and the --writeConcern option set to 0 reduces durability but does not address index creation timing for migration performance.

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238
MCQmedium

A company is migrating a PostgreSQL database to Amazon Aurora PostgreSQL. They have set up AWS DMS with change data capture (CDC). However, after the initial load, the CDC replication is experiencing high latency. What is the MOST likely cause?

A.The target Aurora instance has insufficient storage.
B.The DMS instance is using an older engine version.
C.The source database has large transactions that are not committed quickly.
D.The network bandwidth is too low.
AnswerC

Large uncommitted transactions delay CDC.

Why this answer

Large uncommitted transactions on the source database cause DMS CDC to buffer changes until the transaction commits, leading to high latency. DMS must wait for the commit record before applying changes to the target Aurora instance, and during this time, CDC replication stalls, accumulating a backlog of changes.

Exam trap

The trap here is that candidates often assume network or infrastructure issues (like bandwidth or storage) are the primary cause of CDC latency, overlooking the fundamental constraint that DMS must wait for transaction commits before applying changes.

How to eliminate wrong answers

Option A is wrong because insufficient storage on the target Aurora instance would cause write failures or replication errors, not high latency in CDC replication. Option B is wrong because while older DMS engine versions may lack performance improvements, the most likely cause of CDC latency is source-side transaction behavior, not the DMS version. Option D is wrong because low network bandwidth would cause throughput issues or timeouts, but DMS CDC latency is primarily driven by transaction commit patterns on the source, not network speed.

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239
MCQeasy

A company is deploying a new web application that uses Amazon RDS for MySQL. To meet high availability requirements, the database must automatically failover to a standby in a different Availability Zone with minimal downtime. Which deployment configuration should be used?

A.Multi-AZ deployment with automatic failover
B.Single-AZ deployment with enhanced monitoring
C.Multi-AZ cluster deployment
D.Single-AZ deployment with a read replica
AnswerA

Multi-AZ provides a standby in a different AZ and automatic failover.

Why this answer

A Multi-AZ deployment for Amazon RDS automatically provisions and maintains a synchronous standby replica in a different Availability Zone. If the primary DB instance fails, Amazon RDS automatically fails over to the standby, typically within 60–120 seconds, without requiring manual intervention. This meets the high availability requirement with minimal downtime.

Exam trap

The trap here is that candidates often confuse Multi-AZ deployments (synchronous, automatic failover) with read replicas (asynchronous, manual promotion) or assume that a Multi-AZ cluster deployment applies to standard RDS MySQL, when it is actually an Aurora-specific feature.

How to eliminate wrong answers

Option B is wrong because a Single-AZ deployment with enhanced monitoring provides performance metrics and logs but does not include a standby instance or automatic failover, so it cannot meet the high availability requirement. Option C is wrong because a Multi-AZ cluster deployment is specific to Amazon Aurora, not RDS for MySQL, and uses a different architecture (writer and reader nodes) that is not applicable to standard RDS MySQL. Option D is wrong because a Single-AZ deployment with a read replica provides asynchronous replication and can be manually promoted for failover, but it does not support automatic failover and may incur data loss due to replication lag.

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240
MCQhard

A company is migrating a 2 TB Oracle database to Amazon Aurora PostgreSQL using AWS DMS. The migration is taking longer than expected, and the ongoing replication lag is increasing. Which action would MOST likely improve the migration speed?

A.Enable parallel load on the DMS task.
B.Decrease the DMS task's batch size and commit interval.
C.Increase the DMS replication instance size.
D.Disable the DMS task's logging to reduce overhead.
AnswerC

More resources improve replication performance.

Why this answer

Increasing the replication instance size (Option C) directly addresses the root cause of slow migration and increasing replication lag: insufficient compute or network resources on the DMS instance. A larger instance provides more CPU, memory, and network bandwidth, enabling faster full-load processing and more efficient ongoing replication. This is the most effective action when the instance is resource-constrained, which is common with a 2 TB database.

Exam trap

The trap here is that candidates often assume tuning batch sizes or parallel load settings will fix performance issues, but the question explicitly states the migration is taking longer than expected and replication lag is increasing, which points to an under-provisioned replication instance rather than suboptimal task configuration.

How to eliminate wrong answers

Option A is wrong because enabling parallel load on the DMS task can improve full-load speed but does not address ongoing replication lag; in fact, it can increase resource contention and worsen lag if the instance is already overloaded. Option B is wrong because decreasing batch size and commit interval reduces the number of rows per transaction and increases commit frequency, which actually slows down replication by adding more overhead and reducing throughput. Option D is wrong because disabling logging to reduce overhead is not a recommended practice for troubleshooting or performance tuning; DMS logging is lightweight and disabling it would remove critical diagnostic information without meaningfully improving migration speed.

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241
MCQeasy

A company is migrating a 1 TB SQL Server database to Amazon RDS for SQL Server. They want to use the native backup and restore feature. What must they do first?

A.Upload the backup file to an Amazon S3 bucket.
B.Store the backup file on an EBS volume attached to the RDS instance.
C.Use FTP to transfer the backup file directly to the RDS instance.
D.Use the AWS Management Console to upload the backup file to the RDS instance.
AnswerA

Native restore in RDS SQL Server requires the backup file to be in S3.

Why this answer

To use the native backup and restore feature for migrating a SQL Server database to Amazon RDS, you must first upload the backup file to an Amazon S3 bucket. RDS for SQL Server supports restoring from backup files stored in S3 via the `RESTORE DATABASE` command, using the `FROM URL` option that references the S3 bucket. This is the only supported method for native restore, as RDS does not allow direct file system access or FTP transfers.

Exam trap

The trap here is that candidates assume they can directly upload files to an RDS instance via the console or FTP, similar to an on-premises SQL Server, but RDS abstracts the underlying infrastructure and only supports S3 as the staging location for native backups.

How to eliminate wrong answers

Option B is wrong because you cannot attach an EBS volume to an RDS instance; RDS manages its own storage and does not expose underlying EBS volumes for direct file uploads. Option C is wrong because RDS instances do not support FTP or any direct file transfer protocols; the only way to provide a backup file is through S3. Option D is wrong because the AWS Management Console does not provide a mechanism to upload backup files directly to an RDS instance; the console can be used to initiate a restore from S3, but the file must already reside in S3.

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242
MCQmedium

Refer to the exhibit. An IAM policy is attached to a user who needs to deploy an RDS MySQL instance. After creating the instance, the user tries to modify it to enable deletion protection, but the action fails. What is the most likely reason?

A.The user does not have permission to describe instances.
B.The resource ARN is not specified in the policy.
C.The user does not have permission to enable deletion protection.
D.The user does not have permission to create the instance.
AnswerC

Missing ModifyDBInstance action.

Why this answer

The IAM policy shown in the exhibit grants `rds:CreateDBInstance` but does not include `rds:ModifyDBInstance` or the specific action required to enable deletion protection (`rds:ModifyDBInstance` with the `DeletionProtection` parameter). Enabling deletion protection is a modification action, not part of the creation process, so the user lacks the necessary IAM permission for that operation.

Exam trap

The trap here is that candidates assume the `rds:CreateDBInstance` permission includes the ability to modify any instance property after creation, but AWS IAM separates create and modify actions, and deletion protection specifically requires the `ModifyDBInstance` action.

How to eliminate wrong answers

Option A is wrong because the policy includes `rds:DescribeDBInstances` (implied by `rds:*` or explicitly listed), so the user does have permission to describe instances. Option B is wrong because the policy uses a wildcard `*` for the resource ARN, which covers all RDS resources, so the lack of a specific ARN is not the issue. Option D is wrong because the user successfully created the instance, indicating they have `rds:CreateDBInstance` permission; the failure occurs only when trying to modify the instance to enable deletion protection.

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243
Multi-Selecthard

A company is migrating an on-premises Oracle database to Amazon RDS for Oracle. The migration uses AWS DMS with ongoing replication (CDC). Which TWO tasks must be completed before starting the migration?

Select 2 answers
A.Enable supplemental logging in the Oracle source database
B.Create an Oracle user with required privileges for DMS
C.Configure DMS to use only full load without CDC
D.Disable archive logging on the Oracle source
E.Enable binary logging on the Oracle source
AnswersA, B

Supplemental logging is required for DMS to capture changes.

Why this answer

AWS DMS requires supplemental logging to be enabled on the Oracle source database for ongoing replication (CDC). Supplemental logging ensures that the redo logs contain sufficient information (e.g., primary key, unique key, or all column values) to reconstruct the changes for DMS to capture and apply to the target. Without it, DMS cannot generate the necessary log-based change data for CDC.

Exam trap

The trap here is that candidates may confuse Oracle's redo logging with MySQL's binary logging, leading them to incorrectly select 'Enable binary logging on the Oracle source' (Option E) instead of understanding that Oracle requires supplemental logging for CDC.

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244
Multi-Selectmedium

Which TWO options are valid methods to migrate an on-premises Microsoft SQL Server database to Amazon RDS for SQL Server with minimal downtime? (Choose 2.)

Select 2 answers
A.Use AWS Snowball Edge
B.Use SQL Server Integration Services (SSIS)
C.Use AWS DMS with ongoing replication
D.Use native backup and restore to Amazon S3
E.Use AWS Direct Connect
AnswersC, D

DMS provides CDC for minimal downtime.

Why this answer

AWS DMS with ongoing replication (change data capture) is a valid method for migrating SQL Server to Amazon RDS with minimal downtime because it allows a full load of the source database followed by continuous replication of incremental changes. This keeps the target database nearly synchronized with the source, enabling a short cutover window. The ongoing replication feature uses SQL Server's transaction logs to capture changes without requiring application downtime.

Exam trap

The trap here is that candidates confuse supporting services (Direct Connect, Snowball) with actual migration methods, or mistake batch ETL tools (SSIS) for real-time replication solutions, leading them to select options that do not achieve minimal downtime.

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245
MCQeasy

A company wants to migrate a 10 TB Microsoft SQL Server database from on-premises to Amazon RDS for SQL Server. The migration must be completed within a week and minimize network bandwidth usage. Which approach is most suitable?

A.Back up the database to Amazon S3 using AWS CLI
B.Set up AWS Direct Connect and use DMS
C.Use AWS DMS over the internet
D.Use AWS Snowball Edge to transfer backup files, then restore to RDS
AnswerD

Snowball Edge bypasses network bandwidth constraints.

Why this answer

AWS Snowball Edge is the most suitable approach because it allows you to transfer the 10 TB database backup files physically, bypassing the internet entirely. This eliminates network bandwidth constraints and ensures the migration can be completed within a week, as the data is shipped to AWS and then restored to Amazon RDS for SQL Server using native restore operations.

Exam trap

The trap here is that candidates often overlook the physical transfer option (Snowball) for large migrations, mistakenly assuming that AWS DMS or Direct Connect can handle multi-terabyte datasets within tight deadlines without considering provisioning times or bandwidth constraints.

How to eliminate wrong answers

Option A is wrong because backing up directly to Amazon S3 using AWS CLI over the internet would consume significant bandwidth and likely exceed the one-week timeline for a 10 TB database, especially with limited on-premises upload speeds. Option B is wrong because setting up AWS Direct Connect requires weeks to months for provisioning and is not feasible for a one-week migration, plus it still relies on network bandwidth for the data transfer. Option C is wrong because using AWS DMS over the internet for a 10 TB database would be too slow due to bandwidth limitations and potential network congestion, making it impossible to complete within a week.

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246
Multi-Selecteasy

A company is migrating a 2 TB MongoDB database to Amazon DocumentDB. Which TWO factors should be considered when planning the migration?

Select 2 answers
A.DocumentDB stores backups in Amazon S3 automatically.
B.DocumentDB requires LDAP for authentication.
C.DocumentDB does not support encryption in transit.
D.Source MongoDB version compatibility with DocumentDB.
E.Network bandwidth and latency between source and target.
AnswersD, E

DocumentDB may not support all MongoDB versions.

Why this answer

Amazon DocumentDB is wire-protocol-compatible with MongoDB 3.6 and 4.0, but not with all MongoDB versions. If the source MongoDB version is older or newer than these supported versions, you may need to upgrade or downgrade the source before migration. Compatibility also affects features like indexes, aggregation pipelines, and data types, which can cause migration failures if not addressed.

Option E is correct because network bandwidth and latency directly impact the time required to transfer a 2 TB dataset. Insufficient bandwidth can lead to prolonged migration windows or failures. Additionally, high latency can degrade performance of replication-based tools. Therefore, assessing network capacity and optimizing the transfer path is a critical planning factor.

Exam trap

The trap here is that candidates often focus on operational features of DocumentDB (like automated backups or authentication) as migration planning factors, when the actual critical considerations are source version compatibility and network constraints that directly affect the feasibility and duration of the migration.

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247
MCQeasy

A company is migrating a MySQL database from on-premises to Amazon RDS for MySQL. They want to use native MySQL replication to minimize downtime. Which configuration is required in the on-premises MySQL server?

A.Enable the slow query log
B.Enable binary logging with binlog_format = ROW
C.Enable the audit log
D.Enable the error log
AnswerB

Binary logging is required for MySQL replication.

Why this answer

Native MySQL replication requires binary logging on the source server to capture all changes. Setting binlog_format = ROW ensures that row-level changes are logged, which is the recommended format for cross-version replication and is required by Amazon RDS for MySQL to support replication from an external source. Without binary logging enabled, the on-premises MySQL server cannot act as a replication master.

Exam trap

The trap here is that candidates may confuse logging features (slow query log, audit log, error log) with the binary log, which is the only log that provides the change data stream required for native MySQL replication.

How to eliminate wrong answers

Option A is wrong because enabling the slow query log is used for performance troubleshooting and does not provide the change data stream needed for replication. Option C is wrong because the audit log records user activity for security compliance and does not capture the binary log events required for replication. Option D is wrong because the error log records server errors and warnings, not the transactional changes needed to replicate data to RDS.

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248
MCQhard

A company is migrating a 10 TB Amazon RDS for MySQL database to Amazon Aurora MySQL. The migration must have minimal downtime and must support point-in-time recovery for the source during migration. Which approach meets these requirements?

A.Create a read replica of the source RDS instance, use AWS DMS with CDC from the read replica to Aurora, then promote Aurora.
B.Use mysqldump to export the database, import into Aurora, and point DNS to Aurora.
C.Use AWS DMS with CDC directly from the source RDS instance to Aurora.
D.Take a snapshot of the source RDS instance, restore to Aurora, and point DNS to Aurora.
AnswerA

Read replica minimizes source impact, CDC allows minimal downtime, PITR on source remains.

Why this answer

Creating a read replica of the source RDS for MySQL instance and using AWS DMS with Change Data Capture (CDC) from that replica allows the migration to proceed with minimal downtime. The read replica offloads the CDC overhead from the source, and CDC captures ongoing changes after the full load, enabling a near-zero-downtime cutover. Additionally, the source RDS instance remains fully available for point-in-time recovery (PITR) throughout the migration, as the read replica does not interfere with the source's backup or transaction log retention.

Exam trap

The trap here is that candidates often assume DMS CDC must be run directly from the source for simplicity, overlooking that a read replica isolates the migration workload and preserves the source's point-in-time recovery capabilities, which is a key requirement in this question.

How to eliminate wrong answers

Option B is wrong because using mysqldump for a 10 TB database would require an extended period of downtime to export and import the data, and it does not support ongoing replication (CDC), so it cannot achieve minimal downtime. Option C is wrong because using AWS DMS with CDC directly from the source RDS instance can impact source performance and may interfere with the source's transaction logs needed for point-in-time recovery, especially under heavy write loads; the recommended best practice is to use a read replica to isolate the CDC load. Option D is wrong because taking a snapshot and restoring to Aurora is a one-time, offline migration that does not capture ongoing changes during the migration process, resulting in significant downtime and no support for point-in-time recovery of the source during the migration.

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249
MCQmedium

A company is migrating a MySQL database to Amazon Aurora MySQL. The database has several stored procedures and triggers. During the migration, some stored procedures fail to execute. What is the most likely cause?

A.Aurora does not support stored procedures.
B.The stored procedures exceed the maximum size limit in Aurora.
C.The stored procedures use features that are not compatible with Aurora MySQL.
D.The stored procedures use MyISAM tables, which are not supported by Aurora.
AnswerC

Aurora MySQL has some differences; stored procedures may need modifications.

Why this answer

Aurora MySQL is designed to be compatible with MySQL 5.6, 5.7, and 8.0, but it does not support all MySQL features. Stored procedures that rely on deprecated or non-standard MySQL features, such as certain SQL modes, storage engine-specific syntax, or unsupported functions, will fail to execute after migration. This is the most common cause of stored procedure failures during a migration to Aurora MySQL.

Exam trap

The trap here is that candidates may assume Aurora MySQL is a drop-in replacement for all MySQL features, but the exam tests awareness of specific incompatibilities in stored procedures, triggers, and functions that are not supported or behave differently in Aurora.

How to eliminate wrong answers

Option A is wrong because Aurora MySQL fully supports stored procedures, including triggers and functions, as part of its MySQL compatibility. Option B is wrong because Aurora MySQL does not impose a specific maximum size limit on stored procedures beyond the general MySQL limits (e.g., max_allowed_packet), which are typically not the cause of migration failures. Option D is wrong because while MyISAM tables are not supported by Aurora MySQL (which uses InnoDB only), the question specifically states that stored procedures are failing, not table operations; stored procedures themselves do not depend on MyISAM tables for execution.

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250
MCQhard

A company is migrating a 10 TB MongoDB database to Amazon DocumentDB. The migration must have minimal downtime. Which strategy should be used?

A.Use mongodump to export the database and mongorestore to import into DocumentDB.
B.Use AWS CloudEndure to replicate the MongoDB server to DocumentDB.
C.Copy the database files to Amazon S3 and restore to DocumentDB.
D.Use AWS DMS with MongoDB as source and DocumentDB as target, with change data capture.
AnswerD

AWS DMS supports MongoDB as a source and can perform continuous replication.

Why this answer

AWS DMS with MongoDB as source and DocumentDB as target, using change data capture (CDC), is the correct strategy because it enables a live migration with minimal downtime. DMS performs an initial full load of the 10 TB database and then continuously replicates ongoing changes from the MongoDB oplog, allowing you to cut over to DocumentDB with only a brief pause.

Exam trap

The trap here is that candidates may assume a simple dump-and-restore or file-copy approach is sufficient for large databases, overlooking the need for change data capture to achieve minimal downtime, or they may confuse CloudEndure's server replication capabilities with database-specific migration tools.

How to eliminate wrong answers

Option A is wrong because mongodump/mongorestore is a logical backup and restore method that requires the source database to be quiesced or taken offline during the dump, causing significant downtime for a 10 TB database. Option B is wrong because AWS CloudEndure is designed for block-level replication of entire servers (e.g., physical or virtual machines) to EC2, not for replicating database schemas or data to DocumentDB, which is a managed document database service. Option C is wrong because copying raw MongoDB database files to Amazon S3 and restoring to DocumentDB is not supported; DocumentDB uses its own storage engine and does not accept raw file imports, and this method would also require taking the source offline to ensure file consistency.

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251
MCQhard

A company is migrating a 5 TB PostgreSQL database to Amazon Aurora PostgreSQL. The database has complex stored procedures and triggers. The migration must be completed within a 30-minute downtime window. Which approach would meet the requirement?

A.Use Database Migration Service (DMS) with validation only.
B.Use AWS DMS with full load and ongoing replication, then perform a cutover.
C.Use AWS SCT to convert the schema and then use pg_dump/pg_restore.
D.Set up an Aurora read replica from the source PostgreSQL.
AnswerB

Ongoing replication allows a fast cutover.

Why this answer

AWS DMS with full load and ongoing replication allows you to migrate the 5 TB database with minimal downtime by continuously replicating changes from the source PostgreSQL to the target Aurora PostgreSQL. When you are ready, you perform a cutover, which typically takes only a few minutes, meeting the 30-minute downtime window. The complex stored procedures and triggers are handled because DMS supports ongoing replication for PostgreSQL, capturing DML and DDL changes.

Exam trap

The trap here is that candidates often assume a full dump and restore (pg_dump/pg_restore) is the fastest method for large databases, but they overlook the need for ongoing replication to achieve a short downtime window, and they may incorrectly think Aurora read replicas can be created from external PostgreSQL sources.

How to eliminate wrong answers

Option A is wrong because DMS with validation only does not perform any data migration; it only validates the source and target schemas, so it cannot move the 5 TB database. Option C is wrong because AWS SCT is used for schema conversion, but pg_dump/pg_restore would require a full dump and restore, which for 5 TB would take far longer than 30 minutes and would not support ongoing replication to minimize downtime. Option D is wrong because setting up an Aurora read replica from a source PostgreSQL database is not supported; Aurora read replicas can only be created from an existing Aurora DB cluster, not from an external PostgreSQL instance.

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252
MCQeasy

An organization wants to migrate a 200 GB MySQL database from an on-premises server to Amazon Aurora MySQL. They have a 50 Mbps network connection. The database is 8 hours of downtime. The migration must be completed within 24 hours and costs must be minimized. The team decides to use AWS Database Migration Service (DMS). Which approach best meets the requirements?

A.Create a mysqldump and transfer it over the network to S3, then restore to Aurora.
B.Use AWS DMS with a full load and ongoing replication to minimize downtime.
C.Use AWS Snowball Edge to transfer the data physically.
D.Provision a large EC2 instance to run a parallel export and import.
AnswerB

DMS can handle full load and CDC within constraints.

Why this answer

Using a DMS full load with ongoing replication minimizes downtime and works within the network constraints. Option A is wrong because taking a dump over the network would take too long. Option C is wrong because using Snowball is overkill for 200 GB and shipping would take too long.

Option D is wrong because using a larger instance is unnecessary and costly.

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253
MCQhard

A company is migrating a 4 TB Oracle database to Amazon Aurora PostgreSQL using AWS DMS. The migration completes successfully but the application experiences high latency on the Aurora cluster. The DMS task used LOB mode 'full LOB mode'. What is the most likely cause of the latency?

A.The Aurora cluster was underprovisioned for parallel load
B.Full LOB mode caused large LOBs to be stored in the Aurora cluster, leading to increased I/O
C.The DMS task was configured with 'ongoing replication' causing continuous write load
D.The DMS task replicated data to a different region, causing network latency
AnswerB

Full LOB mode stores LOBs inline, which can cause write amplification and high latency.

Why this answer

Full LOB mode in AWS DMS loads entire LOBs into memory before writing them to the target, which can cause large LOBs to be stored in the Aurora cluster. This increases I/O and storage overhead, leading to high latency on the Aurora cluster, especially if the LOBs are significantly larger than the default chunk size or if the cluster's I/O capacity is exceeded.

Exam trap

The trap here is that candidates often assume 'full LOB mode' is always safe or that latency must be due to ongoing replication or network issues, but the real cause is the I/O impact of storing large LOBs in Aurora's storage engine.

How to eliminate wrong answers

Option A is wrong because underprovisioning for parallel load would cause general performance issues during migration, but the migration completed successfully, and the latency is specifically tied to LOB handling post-migration. Option C is wrong because ongoing replication adds continuous write load, but the question states the migration completed successfully and latency is on the Aurora cluster, not that DMS is still writing; ongoing replication would cause latency during replication, not after. Option D is wrong because replicating to a different region would introduce network latency, but the question does not mention cross-region replication, and the latency is on the Aurora cluster itself, not on the network path.

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254
MCQmedium

A company is deploying a new DynamoDB table for a global application. The table must have low latency reads and writes across multiple AWS regions. Which configuration should be used?

A.Enable DynamoDB Accelerator (DAX) in each region.
B.Use DynamoDB Accelerator (DAX) with cross-region replication.
C.Use DynamoDB global tables with replicate streams.
D.Create a single table in the primary region and use Amazon CloudFront for reads.
AnswerC

Global tables automatically replicate data across regions for low latency access.

Why this answer

DynamoDB global tables provide a fully managed, multi-region, multi-master solution that automatically replicates data across selected AWS Regions, enabling low-latency reads and writes globally. By enabling DynamoDB Streams on the table, global tables use the streams to capture item-level changes and replicate them to other regions, ensuring eventual consistency and high availability for global applications.

Exam trap

The trap here is that candidates often confuse DynamoDB Accelerator (DAX) as a solution for global low-latency reads and writes, overlooking that DAX is single-region and does not replicate data, while global tables are purpose-built for multi-region active-active scenarios.

How to eliminate wrong answers

Option A is wrong because DynamoDB Accelerator (DAX) is an in-memory cache that improves read performance within a single region but does not replicate data across regions, so it cannot provide low-latency writes globally. Option B is wrong because DAX does not support cross-region replication; it is a regional service and cannot be configured to replicate data between regions. Option D is wrong because a single table in one region with CloudFront for reads only accelerates read requests via edge caching, but writes still go to the primary region, causing high latency for writes from other regions, and CloudFront does not handle write operations.

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255
MCQeasy

A company needs to deploy a globally distributed application with a database that supports multi-region writes and automatic conflict resolution. Which AWS database service should be used?

A.Amazon DynamoDB Global Tables
B.Amazon Aurora Global Database
C.Amazon RDS for MySQL with Multi-AZ
D.Amazon ElastiCache for Redis
AnswerA

DynamoDB Global Tables support multi-region active-active writes with conflict resolution.

Why this answer

Amazon DynamoDB Global Tables is the correct choice because it provides a fully managed, multi-Region, multi-active database that replicates data across AWS Regions with automatic conflict resolution using last-writer-wins (LWW) or application-defined conflict resolution. This directly meets the requirement for multi-region writes and automatic conflict resolution without requiring custom replication logic.

Exam trap

The trap here is that candidates often confuse Amazon Aurora Global Database (which is read-only in secondary Regions) with a multi-write solution, but DynamoDB Global Tables is the only AWS database service that natively supports multi-region writes and automatic conflict resolution.

How to eliminate wrong answers

Option B (Amazon Aurora Global Database) is wrong because it supports only one primary Region for writes; secondary Regions are read-only, so it does not support multi-region writes. Option C (Amazon RDS for MySQL with Multi-AZ) is wrong because Multi-AZ provides high availability within a single Region, not multi-region writes or automatic conflict resolution. Option D (Amazon ElastiCache for Redis) is wrong because it is an in-memory cache, not a durable database, and does not support multi-region writes or conflict resolution.

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256
MCQeasy

A company is deploying a new web application on Amazon RDS for MySQL and expects read-heavy traffic. The database must be highly available. Which deployment approach meets these requirements?

A.Deploy a Multi-AZ instance without read replicas.
B.Deploy a Multi-AZ instance and create read replicas.
C.Deploy a Single-AZ instance with a Multi-AZ read replica.
D.Deploy a Single-AZ instance and use ElastiCache for caching.
AnswerB

Multi-AZ for HA, read replicas for read scaling.

Why this answer

Deploying a Multi-AZ RDS for MySQL instance provides automatic failover for high availability, while adding read replicas offloads read-heavy traffic from the primary instance, improving read scalability. Read replicas can be placed in different Availability Zones to further enhance resilience and read performance.

Exam trap

The trap here is that candidates often confuse Multi-AZ standby replicas with read replicas, not realizing that Multi-AZ standby instances cannot serve read traffic, so they fail to address the read-heavy requirement without additional read replicas.

How to eliminate wrong answers

Option A is wrong because a Multi-AZ instance alone provides high availability through synchronous standby replication but does not address read-heavy traffic, as the standby replica cannot serve read queries. Option C is wrong because a Single-AZ instance lacks high availability, and a Multi-AZ read replica does not provide automatic failover for the primary instance; read replicas are for read scaling, not failover. Option D is wrong because while ElastiCache can reduce database read load, it does not provide high availability for the database itself, and a Single-AZ instance remains a single point of failure.

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257
MCQmedium

A company is migrating a 50 GB PostgreSQL database from on-premises to Amazon RDS for PostgreSQL. The network bandwidth between on-premises and AWS is 50 Mbps. The migration must complete within 24 hours. What is the most efficient way to transfer the initial data?

A.Use AWS Snowball to physically transfer the database backup to AWS, then load into RDS.
B.Use AWS DMS to perform a full load directly over the internet.
C.Set up a VPN connection and use AWS DMS with ongoing replication.
D.Use pg_dump to export the database and upload to S3 via the internet, then restore into RDS.
AnswerD

Correct because pg_dump to S3 via the internet leverages the available bandwidth efficiently, and the transfer can complete in a few hours, well within the 24-hour deadline.

Why this answer

The most efficient method is to use pg_dump to export the database, upload the dump file to Amazon S3 via the internet (or using AWS CLI with multipart upload), and then restore it into Amazon RDS for PostgreSQL. Given the database size of 50 GB and a 50 Mbps link, the theoretical transfer time is about 2.3 hours, and even with realistic overhead and retransmissions, it can complete well within the 24-hour window. This approach avoids the shipping delay and logistical overhead of AWS Snowball, which would take several days to arrive and process.

Exam trap

The trap is that candidates overestimate the impact of network overhead and assume Snowball is required for any large data transfer. In reality, for a 50 GB database over a 50 Mbps link, direct network transfer is faster and simpler than physical shipping.

How to eliminate wrong answers

Option B is wrong because AWS DMS over the internet at 50 Mbps would take at least 2.3 hours under perfect conditions, but network overhead, latency, and potential congestion make it unreliable to complete within 24 hours, and DMS is designed for ongoing replication, not just initial bulk transfer. Option C is wrong because setting up a VPN and using DMS with ongoing replication adds unnecessary complexity and latency; the VPN overhead reduces effective throughput, and ongoing replication is not needed for a one-time migration of initial data. Option D is wrong because pg_dump over the internet to S3 would be limited by the same 50 Mbps bandwidth, and the upload time plus the restore time from S3 to RDS would likely exceed 24 hours due to network inefficiencies and the need to download the backup from S3 to the RDS instance.

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258
MCQhard

A company is migrating a 5 TB SQL Server database to Amazon RDS for SQL Server. The migration must be completed within 48 hours with minimal downtime. The network bandwidth between on-premises and AWS is 500 Mbps. What is the MOST efficient migration strategy?

A.Use AWS Snowball to transfer the full database to an RDS instance, then use AWS DMS for ongoing replication
B.Upgrade network bandwidth to 10 Gbps using AWS Direct Connect
C.Use AWS Database Migration Service (AWS DMS) with ongoing replication
D.Use AWS Schema Conversion Tool (AWS SCT) to migrate the schema, then use bulk insert
AnswerA

Snowball transfers data offline, avoiding network bandwidth limitations, then DMS handles ongoing changes.

Why this answer

A 5 TB database over 500 Mbps would take approximately 23 hours for the initial full load alone (5 TB * 8 / 500 Mbps = 80,000 seconds ≈ 22.2 hours), leaving insufficient time for ongoing replication within the 48-hour window. AWS Snowball provides a physical transfer of the full database, bypassing network constraints, and then AWS DMS can perform ongoing change data capture (CDC) replication to apply incremental changes with minimal downtime.

Exam trap

The trap here is that candidates often assume DMS alone can handle large migrations within tight timeframes, underestimating the network transfer time for the full load, and overlook Snowball as a physical transport solution for initial data seeding.

How to eliminate wrong answers

Option B is wrong because upgrading to 10 Gbps Direct Connect is not the most efficient strategy; it would still require a full network transfer of 5 TB, which at 10 Gbps takes about 1.1 hours for the initial load, but provisioning and configuring Direct Connect often takes days or weeks, exceeding the 48-hour migration window. Option C is wrong because using only AWS DMS with ongoing replication would require the initial full load to traverse the 500 Mbps link, taking over 22 hours, and then CDC replication would need to catch up, risking exceeding the 48-hour limit and causing extended downtime. Option D is wrong because AWS Schema Conversion Tool (SCT) is used for heterogeneous migrations (e.g., Oracle to SQL Server), not for homogeneous SQL Server to SQL Server migrations; additionally, bulk insert would still require network transfer of the full 5 TB, which is too slow over 500 Mbps.

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259
MCQeasy

A company is deploying a new RDS for MySQL database and needs to ensure that connections are encrypted using TLS. Which parameter should be configured?

A.Set the ssl_ca parameter to the RDS CA certificate.
B.Set the require_secure_transport parameter to ON.
C.Set the tls_version parameter to TLSv1.2.
D.Set the rds.force_ssl parameter to 1 in the DB parameter group.
AnswerD

rds.force_ssl=1 enforces that all connections use SSL/TLS.

Why this answer

In Amazon RDS for MySQL, the `rds.force_ssl` parameter must be set to 1 in the DB parameter group to enforce TLS/SSL for all connections. This parameter, when enabled, requires clients to use SSL/TLS encryption when connecting to the database instance, ensuring data in transit is encrypted.

Exam trap

The trap here is that candidates often confuse the MySQL native `require_secure_transport` parameter (which is not available in RDS) with the RDS-specific `rds.force_ssl` parameter, or they mistakenly think that setting a TLS version alone enforces encryption.

How to eliminate wrong answers

Option A is wrong because the `ssl_ca` parameter is used to specify the Certificate Authority (CA) certificate for client-side verification, not to enforce encryption; it is typically set on the client side, not in the RDS parameter group. Option B is wrong because `require_secure_transport` is a MySQL Server system variable (available in MySQL 8.0.28+), but it is not supported in Amazon RDS for MySQL; RDS uses `rds.force_ssl` instead. Option C is wrong because setting `tls_version` to TLSv1.2 only restricts the allowed TLS protocol version but does not enforce encryption; clients could still connect without TLS if encryption is not mandated.

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260
MCQhard

A company wants to migrate an on-premises MySQL database to Amazon RDS for MySQL. The database is 500 GB and experiences heavy write traffic. They need to minimize downtime and ensure no data loss. Which approach should they take?

A.Use AWS DMS with a full load task, then cut over the application to RDS.
B.Set up MySQL replication from the on-premises database to RDS, then promote the RDS instance when ready.
C.Create an RDS read replica of the on-premises database, then promote it to a standalone instance.
D.Use mysqldump to export the database and mysql command to import into RDS during a maintenance window.
AnswerB

Replication captures ongoing changes, minimizing downtime and ensuring data consistency.

Why this answer

Setting up native MySQL replication from the on-premises database to Amazon RDS for MySQL allows continuous synchronization with minimal downtime. When ready, you simply stop replication and promote the RDS instance, ensuring zero data loss since all transactions are replicated in near real-time.

Exam trap

The trap here is that candidates confuse AWS DMS's ongoing replication (CDC) with a full load task, or mistakenly think RDS read replicas can be created from external databases, leading them to choose options that either risk data loss or are technically impossible.

How to eliminate wrong answers

Option A is wrong because AWS DMS with a full load task only captures a point-in-time snapshot and does not handle ongoing changes, leading to data loss if writes continue during migration. Option C is wrong because an RDS read replica cannot be created from an on-premises database; read replicas are only supported within AWS RDS or cross-Region, not from external sources. Option D is wrong because mysqldump and mysql import require an application downtime window and do not provide continuous replication, risking data loss if writes occur during the export/import process.

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261
MCQhard

Refer to the exhibit. A database administrator runs the AWS CLI command and gets the following output: {"Engine":"mysql","DBInstanceStatus":"available","MultiAZ":true,"SecondaryAvailabilityZone":"us-east-1b"}. What can be concluded about the database deployment?

A.The database is a Single-AZ deployment.
B.The database has a Read Replica in a different Availability Zone.
C.The database is an Amazon Aurora cluster.
D.The database is a Multi-AZ deployment with a standby in a different Availability Zone.
AnswerD

MultiAZ true and SecondaryAZ present.

Why this answer

The output shows `"MultiAZ":true` and `"SecondaryAvailabilityZone":"us-east-1b"`, which are explicit indicators of a Multi-AZ deployment for an RDS MySQL instance. In a Multi-AZ deployment, Amazon RDS automatically provisions and maintains a synchronous standby replica in a different Availability Zone, and the `SecondaryAvailabilityZone` field confirms the standby's location. This matches option D exactly.

Exam trap

The trap here is that candidates confuse the `SecondaryAvailabilityZone` field with a Read Replica or Aurora's multi-AZ nature, but only a Multi-AZ deployment with a synchronous standby explicitly populates this field in the describe output for a non-Aurora RDS instance.

How to eliminate wrong answers

Option A is wrong because `"MultiAZ":true` directly contradicts a Single-AZ deployment, which would have `"MultiAZ":false` or omit the field. Option B is wrong because Read Replicas are asynchronous and do not appear in the `SecondaryAvailabilityZone` field of the primary instance's describe output; Read Replicas are separate DB instances with their own endpoint. Option C is wrong because Amazon Aurora clusters do not use the `MultiAZ` or `SecondaryAvailabilityZone` fields in the same way; Aurora uses a cluster volume and DB instances across AZs, and the engine would be `aurora-mysql` or `aurora`, not `mysql`.

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262
MCQmedium

A company is deploying a new web application that uses Amazon RDS for MySQL. The application has unpredictable read traffic spikes. The company wants to minimize read latency and automatically scale read capacity. What is the MOST cost-effective solution?

A.Use Amazon ElastiCache as a caching layer
B.Use Amazon RDS Proxy to manage connections
C.Deploy the RDS instance in a Multi-AZ configuration
D.Create an Amazon RDS read replica and configure the application to use it for read traffic
AnswerD

Read replicas offload read traffic and can be scaled manually; they are cost-effective.

Why this answer

Amazon RDS read replicas allow you to offload read traffic from the primary DB instance to one or more replicas, which can be scaled horizontally by adding more replicas as needed. This is the most cost-effective solution among the options for handling unpredictable read spikes because it directly addresses read capacity scaling without the cost of a full caching layer. Multi-AZ provides only high availability, not read scaling; ElastiCache adds cost and complexity; RDS Proxy manages connections but does not scale read capacity.

Exam trap

The trap here is that candidates often confuse Multi-AZ (which provides high availability but no read scaling) with read replicas (which provide read scaling but not automatic failover), leading them to select Multi-AZ as a solution for read performance.

How to eliminate wrong answers

Option A is wrong because Amazon ElastiCache adds operational complexity and cost for a caching layer that may not be necessary for simple read offloading, and it does not directly scale the database's read capacity for unpredictable spikes. Option B is wrong because Amazon RDS Proxy manages connection pooling and improves application scalability, but it does not increase read throughput or reduce read latency for read-heavy workloads. Option C is wrong because Multi-AZ configuration provides high availability and failover support, not read scaling; the standby instance cannot serve read traffic, so it does not help with read spikes.

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263
MCQhard

Refer to the exhibit. A developer deploys this CloudFormation template. An application on the EC2 instance cannot connect to the RDS MySQL database. What is the MOST likely cause?

A.The EC2 security group allows inbound MySQL from 0.0.0.0/0 but the RDS security group only allows traffic from the VPC CIDR, which does not include the EC2 security group.
B.The RDS instance has encryption enabled, preventing access from EC2.
C.The RDS instance has DeletionProtection enabled, which blocks connections.
D.The EC2 instance is in a different Availability Zone than the RDS instance.
AnswerA

RDS SG should allow traffic from EC2 SG, not just VPC CIDR.

Why this answer

The RDS security group only allows inbound MySQL traffic from the VPC CIDR (e.g., 10.0.0.0/16), but the EC2 instance's security group is not referenced. Since the EC2 instance's private IP may fall outside that CIDR (e.g., if it uses a different subnet or a public IP), the RDS security group blocks the connection. Security group rules must explicitly reference the EC2 security group ID to allow traffic from that specific instance, not just the VPC CIDR.

Exam trap

The trap here is that candidates assume a VPC CIDR rule in the RDS security group will automatically cover all EC2 instances in the VPC, but they overlook that the EC2 instance's private IP might be outside that CIDR (e.g., due to subnet allocation or NAT) or that security group referencing is required for proper traffic flow.

How to eliminate wrong answers

Option B is wrong because RDS encryption (using AWS KMS) encrypts data at rest and does not affect network connectivity or authentication; it does not block connections from EC2. Option C is wrong because DeletionProtection prevents accidental deletion of the RDS instance, not inbound connections; it has no impact on database connectivity. Option D is wrong because RDS instances and EC2 instances can communicate across Availability Zones within the same VPC without any connectivity issues, as long as security groups and network ACLs permit the traffic.

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264
MCQeasy

Refer to the exhibit. A database specialist is taking a final snapshot of an RDS DB instance before deletion. The command returns the output shown. The snapshot is at 75% progress. What should the specialist do next?

A.Use the describe-db-snapshots command with --db-snapshot-identifier to get more details.
B.Use the stop-db-instance command to pause the snapshot.
C.Wait for the snapshot status to become 'available' before deleting the instance.
D.Delete the DB instance immediately; the snapshot will continue in the background.
AnswerC

Snapshot must be available before deletion to ensure completeness.

Why this answer

An RDS DB instance cannot be deleted while a final snapshot is in progress; the snapshot must reach the 'available' status first. The AWS CLI output shows the snapshot at 75% progress, meaning the snapshot is still being created. Attempting to delete the instance before the snapshot completes will result in an error, as the deletion operation requires the snapshot to be fully available.

Exam trap

The trap here is that candidates may assume the snapshot continues independently after instance deletion (Option D), but AWS RDS enforces that the instance cannot be deleted until the final snapshot is fully available, preventing data loss.

How to eliminate wrong answers

Option A is wrong because the describe-db-snapshots command with --db-snapshot-identifier would only return the same progress information already shown; it does not change the snapshot status or allow deletion. Option B is wrong because the stop-db-instance command is used to stop a running DB instance, not to pause a snapshot; snapshots are atomic operations that cannot be paused once started. Option D is wrong because deleting the DB instance immediately while the snapshot is in progress will cause the deletion to fail; the snapshot does not continue in the background after instance deletion — the snapshot creation is tied to the instance lifecycle.

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265
MCQhard

A company is deploying a new Amazon DynamoDB table with global tables for a multi-region application. The application requires strongly consistent reads in the primary region and eventual consistency in secondary regions. Which write strategy should they use?

A.Use conditional writes to ensure consistency
B.Use DynamoDB global tables with last writer wins (LWW) conflict resolution
C.Use DynamoDB Streams to replicate writes to secondary regions
D.Use DynamoDB transactions across regions
AnswerB

LWW provides eventual consistency across regions; strong read in primary region is supported.

Why this answer

DynamoDB global tables use last writer wins (LWW) conflict resolution based on the timestamp in the update, which automatically handles concurrent writes across regions. This strategy satisfies the requirement for strongly consistent reads in the primary region and eventual consistency in secondary regions, as global tables replicate data asynchronously and LWW ensures convergence without additional application logic.

Exam trap

The trap here is that candidates often confuse conditional writes or transactions with cross-region consistency mechanisms, not realizing that DynamoDB global tables inherently use LWW and do not support strongly consistent reads across regions.

How to eliminate wrong answers

Option A is wrong because conditional writes are used for optimistic locking or idempotency within a single table, not for cross-region conflict resolution or consistency management in global tables. Option C is wrong because DynamoDB Streams can capture changes but require custom replication logic (e.g., via Lambda) to write to another region, which is not a built-in write strategy for global tables and adds complexity without inherent conflict resolution. Option D is wrong because DynamoDB transactions are limited to a single region and cannot span across regions, making them unsuitable for multi-region write strategies.

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266
MCQeasy

Refer to the exhibit. An IAM policy allows creation of a DMS replication task only if the source database engine is Oracle. A user attempts to create a replication task with a MySQL source. What will happen?

A.The action will fail with an error because the policy is malformed.
B.The action will succeed but the task will fail later.
C.The action will be allowed because the resource is '*'.
D.The action will be denied because the condition does not match.
AnswerD

Condition fails for MySQL.

Why this answer

The IAM policy includes a condition that requires the source engine to be Oracle. When the user attempts to create a DMS replication task with a MySQL source, the condition fails, and IAM denies the action by default. The explicit deny is not needed; IAM uses an implicit deny when no policy statement allows the action under the given conditions.

Exam trap

The trap here is that candidates assume a wildcard resource ('*') grants blanket permission, overlooking that conditions in the Allow statement must be satisfied for the Allow to take effect, and that IAM's default behavior is to deny any request that does not match an applicable Allow.

How to eliminate wrong answers

Option A is wrong because the policy is not malformed; it uses valid IAM policy syntax with a condition block that correctly references the dms:SourceEngine context key. Option B is wrong because the action will not succeed; IAM evaluates policies before the API call is executed, so the task creation is denied immediately and never reaches DMS. Option C is wrong because the resource being '*' does not override the condition; the condition must be satisfied for the Allow to apply, and since it is not, the action is implicitly denied.

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267
Multi-Selecthard

A company is migrating a 3 TB PostgreSQL database to Amazon Aurora PostgreSQL. The migration must have minimal downtime. Which THREE steps should be taken?

Select 3 answers
A.Disable autovacuum on the Aurora cluster to improve migration performance
B.Use AWS DMS with ongoing replication from the source PostgreSQL database
C.Use AWS Snowball Edge to transfer the data offline
D.Create an Aurora PostgreSQL read replica to offload read traffic during migration
E.Increase the instance class of the Aurora cluster to handle the migration load
AnswersB, D, E

DMS with CDC enables near-zero downtime migration.

Why this answer

AWS DMS with ongoing replication (change data capture, CDC) allows continuous synchronization from the source PostgreSQL database to the target Aurora PostgreSQL cluster, enabling a cutover with minimal downtime. This is the standard approach for live migrations where the source remains fully operational during the transfer.

Exam trap

The trap here is that candidates may assume offline methods like Snowball Edge are faster for large datasets, but the question explicitly requires minimal downtime, making continuous replication the only viable choice.

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268
MCQhard

A company is deploying a MongoDB-compatible database using Amazon DocumentDB. The application requires the ability to perform ad-hoc queries on nested fields within documents. Which DocumentDB feature should be enabled to meet this requirement?

A.TTL indexes
B.Indexes on nested fields
C.Transactions
D.Change streams
AnswerB

Indexes allow efficient ad-hoc queries on nested fields.

Why this answer

Amazon DocumentDB supports indexing on nested fields, which allows efficient querying of sub-documents and arrays within documents. By creating indexes on specific nested paths (e.g., "address.city"), the query engine can perform index scans instead of full collection scans, enabling fast ad-hoc queries on nested fields. This feature directly meets the requirement for ad-hoc queries on nested fields.

Exam trap

The trap here is that candidates may confuse indexing features with operational features like TTL or Change streams, assuming any advanced DocumentDB feature can support nested queries, when only explicit indexing on nested fields enables efficient ad-hoc querying on sub-documents.

How to eliminate wrong answers

Option A is wrong because TTL indexes are used to automatically expire documents after a specified time period, not to enable querying on nested fields. Option C is wrong because Transactions provide atomic multi-document operations but do not improve query performance on nested fields. Option D is wrong because Change streams capture real-time data changes (inserts, updates, deletes) for event-driven applications, not for ad-hoc querying of nested fields.

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269
Multi-Selecteasy

A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The migration must be completed with minimal downtime. Which TWO AWS services should be used together?

Select 2 answers
A.AWS Snowball
B.AWS Database Migration Service (DMS)
C.AWS CloudEndure Migration
D.AWS Schema Conversion Tool (SCT)
E.AWS Direct Connect
AnswersB, D

DMS supports ongoing replication for minimal downtime.

Why this answer

AWS Database Migration Service (DMS) is the correct choice because it supports ongoing replication from an on-premises PostgreSQL source to Amazon RDS for PostgreSQL, enabling near-zero downtime migrations. DMS uses change data capture (CDC) to continuously replicate transactions after an initial full load, allowing the target database to stay synchronized until cutover.

Exam trap

The DBS-C01 exam often tests the misconception that AWS DMS alone is sufficient for a homogeneous migration, but the question requires TWO services, and the trap is that candidates overlook the Schema Conversion Tool (SCT) because they assume no schema changes are needed for PostgreSQL-to-PostgreSQL, ignoring potential incompatibilities with extensions or unsupported features in RDS.

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270
MCQeasy

A company wants to migrate a 1 TB on-premises PostgreSQL database to Amazon RDS for PostgreSQL. They have a limited internet bandwidth. Which service should they use to accelerate the migration?

A.AWS Snowball Edge
B.AWS Database Migration Service (DMS)
C.Amazon S3
D.AWS Direct Connect
AnswerA

Offline data transfer bypasses bandwidth limitations.

Why this answer

AWS Snowball Edge is the correct choice because it provides a physical storage device that can be used to transfer large volumes of data (1 TB) over a limited internet bandwidth. By shipping the device to AWS, the initial bulk data load bypasses the internet entirely, which accelerates the migration. After the data is loaded into Amazon RDS for PostgreSQL via Snowball Edge, AWS DMS can be used for ongoing replication to keep the database in sync.

Exam trap

The trap here is that candidates often assume AWS DMS is always the best choice for database migrations, but they overlook the critical constraint of limited bandwidth, which makes a physical appliance like Snowball Edge the only viable option for accelerating the initial bulk transfer.

How to eliminate wrong answers

Option B (AWS DMS) is wrong because while DMS is the primary service for database migrations, it relies on network connectivity to transfer data; with limited internet bandwidth, a 1 TB migration would be extremely slow or impractical. Option C (Amazon S3) is wrong because S3 is an object storage service, not a migration service; it cannot directly migrate a PostgreSQL database to RDS, and uploading 1 TB to S3 over limited bandwidth would still be slow. Option D (AWS Direct Connect) is wrong because it establishes a dedicated network connection, but it requires significant setup time and cost, and does not inherently accelerate the data transfer if the underlying internet bandwidth is limited; it also does not address the physical data transfer challenge.

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271
MCQeasy

A company needs to migrate a 100 GB on-premises SQL Server database to Amazon RDS for SQL Server. The migration must be completed within a 4-hour maintenance window. The network link has 500 Mbps throughput. Which approach should be used?

A.Use AWS DMS with full load and CDC
B.Use native SQL Server backup to S3, then restore to RDS
C.Use AWS Snowball Edge to transfer the backup
D.Launch an EC2 instance with SQL Server, copy the database, and then migrate to RDS
AnswerB

This method can be fast and fits within the maintenance window with 500 Mbps.

Why this answer

Native SQL Server backup to S3 and restore to RDS is the fastest method for a 100 GB database over a 500 Mbps link. At 500 Mbps, the theoretical transfer time for 100 GB is approximately 28 minutes (100 GB * 8 / 500 Mbps), well within the 4-hour window, making Snowball unnecessary. This approach avoids the overhead of change data capture (CDC) and additional compute resources, directly leveraging SQL Server's native backup/restore capabilities.

Exam trap

The trap here is that candidates overestimate the time required for network transfer and assume Snowball is necessary for any database over a few gigabytes, ignoring that a 500 Mbps link can transfer 100 GB in under 30 minutes, well within the 4-hour window.

How to eliminate wrong answers

Option A is wrong because AWS DMS with full load and CDC introduces unnecessary complexity and overhead for a one-time migration that can be completed within the maintenance window using a simpler backup/restore method; CDC is designed for ongoing replication, not a single batch transfer. Option C is wrong because AWS Snowball Edge is overkill for a 100 GB database when the network link (500 Mbps) can transfer the data in under 30 minutes, and Snowball adds logistics delays (shipping, preparation) that exceed the 4-hour window. Option D is wrong because launching an EC2 instance with SQL Server, copying the database, and then migrating to RDS adds extra steps and cost without benefit; the native backup to S3 and restore to RDS is more direct and avoids intermediate compute resources.

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272
MCQmedium

A company is migrating a 3 TB Oracle database to Amazon RDS for Oracle. They want to use Oracle Data Pump to export the data and then import it into RDS. What is the most efficient way to transfer the dump files to AWS?

A.Use AWS Snowball to physically ship the dump files to AWS.
B.Use AWS DMS to migrate the data directly from Oracle to RDS for Oracle.
C.Upload the dump files to Amazon S3 and then import them into RDS for Oracle using Oracle Data Pump.
D.Transfer the dump files over a VPN connection to an EC2 instance and then copy to RDS.
AnswerC

S3 provides scalable storage and fast upload; RDS can read from S3 for import.

Why this answer

Uploading Oracle Data Pump dump files to Amazon S3 and then importing them into Amazon RDS for Oracle using the DBMS_DATAPUMP API is the most efficient method for transferring large dump files. This approach leverages S3 for scalable, durable storage and high-throughput transfer, avoiding network bottlenecks or physical shipping delays. The RDS for Oracle instance can directly access the S3 bucket via an IAM role, enabling a seamless import process.

Exam trap

The trap here is that candidates may assume AWS Snowball is always the best choice for large data transfers, but for 3 TB with available network bandwidth, direct S3 upload is more efficient and avoids physical shipping delays.

How to eliminate wrong answers

Option A is wrong because AWS Snowball is designed for petabyte-scale data transfers where network bandwidth is insufficient, but for a 3 TB database, uploading to S3 over a high-speed internet connection or AWS Direct Connect is more efficient and avoids the logistical overhead of physical shipping. Option B is wrong because AWS DMS is a continuous replication tool for migrating live databases with minimal downtime, not for importing static Data Pump dump files; it would require a separate schema conversion and does not use Oracle Data Pump. Option D is wrong because transferring dump files over a VPN to an EC2 instance and then copying to RDS adds unnecessary intermediate steps and latency, whereas direct upload to S3 provides faster, parallelized transfer and native integration with RDS for Oracle.

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273
Multi-Selectmedium

A company is migrating a self-managed MongoDB database to Amazon DocumentDB (with MongoDB compatibility). Which TWO actions should the company take to ensure a successful migration? (Choose two.)

Select 2 answers
A.Use AWS Schema Conversion Tool (SCT) to convert MongoDB schemas to DocumentDB compatible format.
B.Use AWS Database Migration Service (DMS) to migrate data from MongoDB Atlas to DocumentDB.
C.Use AWS DMS to perform a full load and ongoing replication from MongoDB to DocumentDB.
D.Use AWS DMS with an Amazon EBS snapshot as the source for the migration.
E.Use AWS DMS to migrate data from MongoDB to Amazon DynamoDB, then import into DocumentDB.
AnswersA, C

SCT helps convert schemas for compatibility.

Why this answer

AWS Schema Conversion Tool (SCT) can convert MongoDB schemas to a format compatible with Amazon DocumentDB, handling data type mappings and index definitions. This is essential because DocumentDB uses a different storage engine and schema structure than MongoDB, and SCT automates the conversion of collections, indexes, and validation rules to ensure compatibility before migration.

Exam trap

The trap here is that candidates often assume DMS can migrate from any MongoDB deployment (including Atlas) or that EBS snapshots are valid sources, but DMS strictly requires a live MongoDB endpoint with oplog access for CDC.

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274
MCQeasy

A company is deploying Amazon DynamoDB for a new application. The application requires single-digit millisecond latency for read operations. Which DynamoDB feature should be configured to meet this requirement?

A.DynamoDB Accelerator (DAX)
B.DynamoDB Streams
C.Auto Scaling
D.Time to Live (TTL)
AnswerA

DAX provides in-memory caching for fast reads.

Why this answer

DynamoDB Accelerator (DAX) is an in-memory caching service that sits between your application and DynamoDB, providing microsecond to single-digit millisecond latency for read-heavy workloads. By caching frequently accessed items, DAX offloads read traffic from the underlying DynamoDB tables, ensuring consistent low-latency responses even under high concurrency.

Exam trap

The trap here is that candidates may confuse DynamoDB Streams (a change-data-capture feature) with a performance optimization tool, or assume Auto Scaling directly reduces latency when it only manages throughput capacity.

How to eliminate wrong answers

Option B (DynamoDB Streams) is wrong because it captures a time-ordered sequence of item-level changes in a table for event-driven processing, not for improving read latency. Option C (Auto Scaling) is wrong because it automatically adjusts provisioned throughput capacity based on traffic patterns, but it does not reduce read latency — it only helps maintain throughput under varying load. Option D (Time to Live) is wrong because it automatically deletes expired items from tables to manage storage costs, with no impact on read performance or latency.

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275
MCQeasy

A company wants to migrate a 200 GB SQL Server database to Amazon RDS for SQL Server with minimal downtime. The database is used by a critical application. Which service should be used for the migration?

A.AWS Schema Conversion Tool (SCT).
B.AWS Database Migration Service (DMS).
C.SQL Server Import and Export Wizard.
D.SQL Server Management Studio (SSMS) backup and restore.
AnswerB

DMS supports near-zero downtime migration with CDC.

Why this answer

AWS DMS is the correct choice because it supports ongoing replication (change data capture) from a SQL Server source to an Amazon RDS for SQL Server target, enabling a migration with minimal downtime. DMS can perform a full load of the 200 GB database and then continuously replicate changes until the cutover, which is essential for a critical application that cannot tolerate extended downtime.

Exam trap

The trap here is that candidates often confuse AWS SCT (schema conversion) with AWS DMS (data migration), assuming SCT can also handle data movement, when in fact SCT only converts schema and assesses compatibility, while DMS handles the actual data transfer and ongoing replication.

How to eliminate wrong answers

Option A is wrong because AWS Schema Conversion Tool (SCT) is used for converting database schemas to a different database engine (e.g., SQL Server to Aurora), not for migrating data to the same engine with minimal downtime. Option C is wrong because the SQL Server Import and Export Wizard is a manual, one-time data transfer tool that does not support ongoing replication, resulting in significant downtime for a 200 GB database. Option D is wrong because SSMS backup and restore requires taking a full backup, transferring it, and restoring, which incurs downtime during the backup and restore process and does not support continuous replication for minimal downtime.

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276
MCQeasy

A company wants to migrate its on-premises Oracle database to Amazon Aurora PostgreSQL. The company needs to automatically convert the Oracle schema to PostgreSQL-compatible format. Which AWS service should the company use?

A.AWS Database Migration Service (AWS DMS) with the Oracle native dump and load option
B.AWS Server Migration Service (AWS SMS)
C.AWS Database Migration Service (AWS DMS)
D.AWS Schema Conversion Tool (AWS SCT)
AnswerD

AWS SCT automates schema conversion from Oracle to Amazon Aurora PostgreSQL.

Why this answer

AWS Schema Conversion Tool (AWS SCT) is designed specifically to convert database schemas from one engine to another, including Oracle to Amazon Aurora PostgreSQL. It automatically translates Oracle DDL (tables, indexes, stored procedures, functions, etc.) into PostgreSQL-compatible format, handling data type mappings, PL/SQL to PL/pgSQL conversion, and other schema-level transformations. AWS DMS handles data migration, not schema conversion, making SCT the correct choice for this requirement.

Exam trap

The trap here is that candidates confuse AWS DMS's data migration capability with schema conversion, assuming DMS can automatically transform the schema, when in fact DMS only moves data and requires SCT for schema translation.

How to eliminate wrong answers

Option A is wrong because AWS DMS with the Oracle native dump and load option is used for bulk data transfer, not schema conversion; it does not automatically translate Oracle schema objects to PostgreSQL format. Option B is wrong because AWS Server Migration Service (SMS) is designed for migrating on-premises virtual machines to AWS, not for database schema conversion. Option C is wrong because AWS DMS migrates data (rows and tables) but does not perform schema transformation; it relies on AWS SCT to first convert the schema before data migration.

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277
MCQmedium

Refer to the exhibit. A company wants to migrate this RDS MySQL instance to an Aurora MySQL cluster with encryption at rest. What is the most efficient approach?

A.Use AWS DMS to migrate the database to an encrypted Aurora cluster.
B.Create a snapshot of the RDS instance, copy the snapshot with encryption, then restore to an Aurora cluster.
C.Create a snapshot of the RDS instance and restore it directly to an Aurora cluster.
D.Create an encrypted read replica in Aurora and promote it.
AnswerB

Copying the snapshot enables encryption, then restoring to Aurora creates an encrypted cluster.

Why this answer

It is the most efficient approach to migrate an RDS MySQL instance to an encrypted Aurora MySQL cluster. You first create a snapshot of the RDS instance, then copy that snapshot with encryption enabled (using an AWS KMS key), and finally restore the encrypted snapshot to an Aurora cluster. This method ensures encryption at rest is applied during the migration without requiring additional data transfer or schema conversion.

Exam trap

The trap here is that candidates often assume DMS is the only migration tool for cross-engine or encryption changes, but for RDS MySQL to Aurora MySQL with encryption, a snapshot copy with encryption is more efficient and avoids unnecessary data movement.

How to eliminate wrong answers

Option A is wrong because AWS DMS would require a full data migration, which is less efficient than using a snapshot restore, and DMS does not automatically enable encryption at rest on the target Aurora cluster unless explicitly configured. Option C is wrong because restoring a snapshot directly to an Aurora cluster does not enable encryption at rest; the snapshot must be copied with encryption first. Option D is wrong because creating an encrypted read replica in Aurora and promoting it is not possible; Aurora read replicas inherit the encryption setting of the source cluster, and you cannot add encryption to an existing unencrypted cluster via replication.

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278
MCQhard

A company wants to migrate a 2 TB Amazon RDS for MySQL DB instance to Amazon Aurora MySQL. The migration must have zero downtime and must be reversible for 48 hours. Which strategy meets these requirements?

A.Create an Aurora MySQL Read Replica from the RDS MySQL instance, then promote the replica to a standalone Aurora cluster.
B.Take a snapshot of the RDS MySQL instance, restore it to Aurora MySQL, and update the DNS.
C.Export the database using mysqldump, import into Aurora, and switch DNS.
D.Use AWS DMS with ongoing change data capture (CDC) to migrate to Aurora.
AnswerA

Read replica creation is online, promotion is fast. Fallback by deleting Aurora cluster within 48 hours.

Why this answer

Creating an Aurora MySQL Read Replica from an RDS MySQL instance uses MySQL's native asynchronous replication to keep the Aurora cluster in sync with the source, allowing a near-zero-downtime cutover by promoting the replica. The migration is fully reversible within 48 hours because the original RDS instance remains unchanged and can continue serving traffic if the promotion is rolled back.

Exam trap

The trap here is that candidates often assume AWS DMS with CDC is the only zero-downtime option, but they overlook the reversibility requirement, which is better met by the native RDS-to-Aurora replica feature that keeps the source intact.

How to eliminate wrong answers

Option B is wrong because taking a snapshot and restoring to Aurora requires downtime during the restore and DNS switch, and it is not reversible without restoring another snapshot. Option C is wrong because mysqldump export and import involves significant downtime during the data transfer and is not reversible without a full re-import. Option D is wrong because AWS DMS with CDC can achieve zero downtime, but it is not inherently reversible for 48 hours without additional infrastructure (e.g., maintaining a reverse replication task), and the question specifies a reversible strategy that keeps the original RDS instance available.

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279
MCQhard

Refer to the exhibit. A database administrator has this IAM policy attached to their user. They attempt to delete the database instance 'prod-mydb' but receive an 'AccessDenied' error. Why?

A.The policy does not allow the rds:DeleteDBInstance action for any resource.
B.The resource ARN in the Deny statement does not match the instance.
C.The user does not have permission to describe the DB instance.
D.The Deny statement explicitly denies deletion of any instance with an identifier starting with 'prod-'.
AnswerD

The Deny statement overrides the Allow, preventing deletion of prod instances.

Why this answer

The IAM policy includes an explicit Deny statement that denies the rds:DeleteDBInstance action when the resource ARN contains an instance identifier starting with 'prod-'. Explicit Deny statements override any Allow statements, so even if another policy allows deletion, this Deny blocks it for instances like 'prod-mydb'.

Exam trap

The trap here is that candidates often overlook the explicit Deny statement and focus only on the Allow statement, assuming the user has permission because the action is allowed for some resources, but they miss that the Deny specifically blocks the targeted instance identifier pattern.

How to eliminate wrong answers

Option A is wrong because the policy does allow the rds:DeleteDBInstance action for resources matching the condition in the Allow statement, but the explicit Deny overrides it. Option B is wrong because the resource ARN in the Deny statement uses a wildcard pattern (arn:aws:rds:*:*:db:prod-*) that matches the instance identifier 'prod-mydb', so the ARN does match. Option C is wrong because the error is 'AccessDenied' for the delete action, not for describing the instance; the user's ability to describe the instance is irrelevant to the delete permission.

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280
MCQeasy

A company is deploying Amazon RDS for PostgreSQL and needs to ensure that all data at rest is encrypted. Which action should be taken to enable encryption?

A.Specify an AWS KMS key when creating the RDS instance.
B.Modify the existing RDS instance to enable encryption.
C.Enable encryption by default in the RDS console.
D.Enable encryption using S3 server-side encryption.
AnswerA

RDS encryption uses KMS keys and must be set at creation.

Why this answer

Amazon RDS for PostgreSQL supports encryption at rest using AWS Key Management Service (KMS). Encryption must be enabled at instance creation time by specifying an AWS KMS key; it cannot be enabled on an existing unencrypted instance. This ensures that the underlying storage, automated backups, read replicas, and snapshots are encrypted using the chosen KMS key.

Exam trap

The trap here is that candidates assume encryption can be toggled on after creation (like enabling encryption on an existing EBS volume), but RDS requires encryption to be set at launch time, and modifying an existing instance does not offer this option.

How to eliminate wrong answers

Option B is wrong because RDS does not allow enabling encryption on an existing unencrypted DB instance; you must create a new encrypted instance and migrate the data. Option C is wrong because there is no 'enable encryption by default' setting in the RDS console; encryption is an instance-level attribute set only during creation. Option D is wrong because S3 server-side encryption is used for objects stored in Amazon S3, not for RDS database volumes; RDS encryption uses KMS keys for EBS volumes and storage.

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281
MCQhard

A company is deploying a new multi-AZ application that requires a relational database. The database must be highly available and must automatically failover to a standby in another Availability Zone within minutes. The database size is 500 GB and the workload is read-heavy. Which AWS RDS configuration meets these requirements?

A.Deploy Amazon Aurora with Multi-AZ
B.Deploy Amazon RDS for PostgreSQL with a cross-Region read replica
C.Deploy Amazon RDS for MySQL with Multi-AZ and a read replica in a different AZ
D.Deploy Amazon RDS for Oracle with RDS Proxy
AnswerC

Multi-AZ provides automatic failover; read replica improves read performance.

Why this answer

Deploying Amazon RDS for MySQL with Multi-AZ provides automatic failover to a standby in a different Availability Zone within minutes, meeting the high availability requirement. Adding a read replica in a different AZ offloads read traffic, which is ideal for the read-heavy workload, without affecting the primary database's performance.

Exam trap

The trap here is that candidates may confuse Aurora's built-in high availability with the explicit 'Multi-AZ' feature of RDS, or assume that a cross-Region read replica provides automatic failover, when in fact it requires manual promotion and does not meet the 'within minutes' automatic failover requirement.

How to eliminate wrong answers

Option A is wrong because Amazon Aurora with Multi-AZ is not a valid configuration; Aurora inherently provides high availability across AZs with its cluster architecture, but the term 'Multi-AZ' is specific to RDS, and Aurora uses a different failover mechanism that may not meet the 'within minutes' requirement as precisely as RDS Multi-AZ. Option B is wrong because a cross-Region read replica provides disaster recovery and read scaling, but it does not offer automatic failover within the same region; failover would require manual intervention or additional setup, and it does not meet the 'within minutes' automatic failover requirement. Option D is wrong because RDS Proxy is a connection pooling service that improves application scalability and resilience, but it does not provide database-level high availability or automatic failover; it is not a substitute for Multi-AZ deployment.

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282
Multi-Selectmedium

Which TWO factors should be considered when selecting a migration method from on-premises Oracle to Amazon RDS for Oracle?

Select 2 answers
A.The size of the database and available network bandwidth
B.The version of the Oracle client used by applications
C.The required downtime tolerance
D.The number of stored procedures in the database
E.The number of indexes on the source database
AnswersA, C

Large databases may require Snowball; bandwidth affects transfer time.

Why this answer

The size of the database directly impacts the time required for data transfer, and available network bandwidth determines the maximum throughput for that transfer. For large databases over limited bandwidth, full offline migration may be impractical, requiring incremental or online methods like AWS DMS with ongoing replication to minimize transfer time.

Exam trap

The trap here is that candidates confuse factors affecting migration method selection with factors affecting post-migration performance or compatibility, such as client versions or object counts, which are not relevant to the method choice.

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283
MCQmedium

A company is migrating a MongoDB database to Amazon DocumentDB. They have a 200 GB database and need to minimize downtime. Which migration approach is most appropriate?

A.Take an EBS snapshot of the MongoDB volume and restore it to DocumentDB.
B.Set up MongoDB replication from the source to DocumentDB, then promote DocumentDB.
C.Export the database using mongodump and import using mongorestore into DocumentDB.
D.Use AWS DMS to migrate data from MongoDB to DocumentDB.
AnswerD

AWS DMS with ongoing replication (CDC) allows initial load and continuous sync, minimizing downtime. This is the recommended approach for large databases requiring minimal interruption.

Why this answer

AWS DMS with ongoing replication (change data capture) is the most appropriate migration approach for minimizing downtime when migrating a 200 GB MongoDB database to Amazon DocumentDB. DMS can perform an initial load and then continuously replicate ongoing changes from the source MongoDB to the target DocumentDB until cutover, resulting in near-zero downtime. Option B is incorrect because native MongoDB replication is not supported by DocumentDB; DocumentDB cannot join a MongoDB replica set.

Exam trap

Candidates may think that native MongoDB replication to DocumentDB is possible, but DocumentDB uses a different replication mechanism and cannot act as a MongoDB replica. The correct tool for minimal downtime migration is AWS DMS with ongoing replication.

How to eliminate wrong answers

Option A is wrong because EBS snapshots capture block-level data of an EC2 instance volume, not the logical database state, and DocumentDB does not support restoring from an EBS snapshot; it uses its own storage engine. Option C is wrong because mongodump/mongorestore is an offline, logical export/import process that requires the source database to be quiesced or read-locked during the dump, causing significant downtime for a 200 GB database. Option D is wrong because AWS DMS for MongoDB to DocumentDB migrations uses a CDC (change data capture) approach that relies on the MongoDB oplog, but DMS does not support DocumentDB as a target for MongoDB source migrations; DMS supports MongoDB to Amazon DynamoDB or Amazon S3, but not to DocumentDB.

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284
MCQeasy

A company is migrating an on-premises MongoDB database to Amazon DocumentDB (with MongoDB compatibility). They want to validate that the data is consistent after migration. Which tool should they use?

A.mongoexport and mongoimport
B.dbHash command on both databases
C.DocumentDB native consistency check tool
D.AWS DMS data validation
AnswerD

DMS can validate data between source and target.

Why this answer

AWS DMS data validation is the correct tool because it provides built-in, row-level checksum-based validation that compares source and target data after a full load or ongoing replication. For DocumentDB migrations, DMS can compute and compare checksums on the fly, ensuring consistency without requiring manual scripting or external tools. This is the recommended AWS approach for validating data integrity during and after a migration to DocumentDB.

Exam trap

The trap here is that candidates assume a native MongoDB command like dbHash or a generic export/import tool can validate consistency across different database engines, but DocumentDB does not support dbHash and AWS DMS is the only service-integrated validation method for cross-engine migrations.

How to eliminate wrong answers

Option A is wrong because mongoexport and mongoimport are data export/import utilities, not validation tools; they cannot compare existing data in both databases for consistency. Option B is wrong because the dbHash command computes a hash of all data in a MongoDB instance, but DocumentDB does not support the dbHash command natively, and it would require custom scripting to compare hashes across different database engines. Option C is wrong because there is no native 'DocumentDB native consistency check tool' — DocumentDB relies on AWS DMS or manual methods for consistency validation, not a built-in tool.

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285
Multi-Selectmedium

A company is migrating a 1 TB on-premises SQL Server database to Amazon RDS for SQL Server. The migration must be completed within 24 hours and with minimal downtime. Which TWO approaches should be used? (Choose 2)

Select 2 answers
A.Use AWS DMS with SSIS packages.
B.Use native backup and restore to S3.
C.Use AWS DMS with ongoing replication (CDC).
D.Use AWS SCT to assess and convert the schema.
E.Use AWS DMS full load only.
AnswersC, D

Near-zero downtime migration.

Why this answer

AWS DMS with ongoing replication (CDC) allows you to perform a full load of the existing data and then continuously replicate changes from the source SQL Server database to Amazon RDS for SQL Server, minimizing downtime to just the final cutover window. This approach meets the 24-hour migration window and the requirement for minimal downtime by keeping the target database nearly synchronized with the source until you are ready to switch.

Exam trap

The trap here is that candidates often confuse a full-load-only DMS task (Option E) with a full-load-plus-CDC task (Option C), assuming any DMS migration automatically minimizes downtime, but only CDC provides ongoing replication to reduce the cutover window.

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286
Multi-Selecthard

Which TWO steps are required when migrating an Oracle database to Amazon RDS for Oracle using AWS DMS with ongoing replication? (Choose TWO.)

Select 2 answers
A.Run AWS Schema Conversion Tool (SCT) to convert the schema.
B.Enable minimal supplemental logging.
C.Enable archive logging on the source Oracle database.
D.Enable supplemental logging for all columns.
E.Create a VPC endpoint for the DMS replication instance.
AnswersC, D

DMS needs archive logs to capture changes.

Why this answer

AWS DMS requires archive logging on the source Oracle database to capture ongoing changes for continuous replication. Archive logging ensures that redo logs are retained and available for DMS to read transaction changes after a log switch, enabling Change Data Capture (CDC) without data loss.

Exam trap

The trap here is that candidates often confuse minimal supplemental logging (which is sufficient for Oracle GoldenGate) with the full supplemental logging required by AWS DMS, leading them to incorrectly select option B instead of D.

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287
MCQhard

A company is migrating an on-premises MongoDB database to Amazon DocumentDB. The migration must be online with minimal downtime. The source MongoDB is version 4.0 and uses replica sets. Which tool should the company use?

A.Use MongoDB Compass to export data and import into DocumentDB.
B.Use mongodump and mongorestore.
C.Create a read replica of the MongoDB replica set and promote to DocumentDB.
D.Use AWS DMS with MongoDB as source and DocumentDB as target.
AnswerD

DMS supports ongoing replication from MongoDB to DocumentDB.

Why this answer

AWS DMS (Database Migration Service) supports continuous replication from MongoDB (including replica sets) to Amazon DocumentDB, enabling an online migration with minimal downtime. DMS uses the MongoDB oplog to capture ongoing changes, ensuring data consistency during the cutover. This is the only option that meets the requirement for an online migration with minimal downtime.

Exam trap

The trap here is that candidates often confuse a MongoDB read replica promotion (which works within native MongoDB clusters) with cross-service migration to DocumentDB, which requires a purpose-built tool like DMS for online replication.

How to eliminate wrong answers

Option A is wrong because MongoDB Compass is a GUI tool for ad-hoc data export/import, not designed for continuous replication or minimal downtime migrations. Option B is wrong because mongodump and mongorestore perform a snapshot-based, offline migration that requires stopping writes, causing significant downtime. Option C is wrong because you cannot promote a MongoDB read replica to become an Amazon DocumentDB cluster; DocumentDB is a separate service with its own replication mechanism, not a MongoDB replica set member.

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288
MCQmedium

A company is migrating a 500 GB Oracle database to Amazon RDS for Oracle. The migration must complete within a 4-hour downtime window. The network bandwidth is 1 Gbps. Which migration approach minimizes the migration time?

A.Use AWS Schema Conversion Tool (SCT) to convert the schema, then use AWS DMS for data migration.
B.Use Oracle Data Pump to export and import the database.
C.Use AWS DMS to perform a full load of the database to RDS.
D.Use AWS DataSync to copy the database files to Amazon S3, then restore to RDS.
AnswerC

DMS can efficiently migrate data directly to RDS, minimizing migration time.

Why this answer

AWS DMS performs a full load directly from the source Oracle database to the target RDS for Oracle instance over the network, leveraging the 1 Gbps bandwidth efficiently. For a 500 GB database, a full load at 1 Gbps (theoretical max ~450 Gbps per hour) can complete in under 2 hours, well within the 4-hour window, without requiring intermediate storage or schema conversion.

Exam trap

The trap here is that candidates often overcomplicate the migration by choosing tools like SCT or DataSync, not realizing that for homogeneous Oracle-to-Oracle migrations, a direct DMS full load is the simplest and fastest approach, and that Data Pump or file-based methods introduce unnecessary overhead.

How to eliminate wrong answers

Option A is wrong because the AWS Schema Conversion Tool (SCT) is used for heterogeneous migrations (e.g., Oracle to Aurora PostgreSQL) and is unnecessary for Oracle-to-Oracle migrations; adding SCT would introduce extra steps and time, not minimize migration time. Option B is wrong because Oracle Data Pump export/import requires writing to a file system (e.g., EBS or S3) and then transferring those files, which adds I/O overhead and network transfer time for the entire 500 GB, often exceeding the 4-hour window due to export/import processing and file copy latency. Option D is wrong because AWS DataSync is designed for file-based transfers to S3, not for direct database migration; restoring from S3 to RDS would require additional steps (e.g., using Oracle RMAN or Data Pump), adding complexity and time, and the full 500 GB must be uploaded and then restored, which is slower than a direct DMS full load.

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289
MCQhard

A company is migrating a 1 TB Oracle database to Amazon RDS for Oracle. The source database has a high volume of small transactions. The migration must minimize source database impact. Which AWS DMS configuration should be used?

A.Use batch-optimized apply mode
B.Use full load only and disable ongoing replication
C.Use full load with CDC (ongoing replication)
D.Use multiple DMS tasks to parallelize the migration
AnswerB

Full load only does not require CDC, minimizing impact.

Why this answer

Using full load only with ongoing replication disabled minimizes source database impact by avoiding the overhead of capturing and applying continuous change data capture (CDC) logs. The high volume of small transactions would otherwise generate a large number of redo log switches and increase I/O on the source, which is contrary to the requirement to minimize impact. A full load only migration transfers a snapshot of the data once, reducing the source load to a single consistent read operation.

Exam trap

The trap here is that candidates often assume CDC is always necessary for a complete migration, but the question explicitly prioritizes minimizing source impact over minimizing downtime, making full load only the correct choice despite the lack of ongoing replication.

How to eliminate wrong answers

Option A is wrong because batch-optimized apply mode is a target-side optimization that batches changes for apply, but it does not reduce source impact; it still requires CDC to capture changes, which would generate significant redo log overhead on the source. Option C is wrong because full load with CDC (ongoing replication) requires continuous reading of the source redo logs to capture changes, which adds persistent I/O and log generation overhead, directly conflicting with the requirement to minimize source database impact. Option D is wrong because using multiple DMS tasks to parallelize the migration increases the number of concurrent connections and read operations on the source, amplifying rather than minimizing the impact.

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290
MCQeasy

A company is migrating a 100 GB MySQL database to Amazon Aurora MySQL. The migration must have minimal downtime and the source database is currently in use. Which approach should the company take?

A.Create an Aurora Replica from the on-premises MySQL database and promote it.
B.Export the database using mysqldump and import it into Aurora during a maintenance window.
C.Take a physical backup of the MySQL database, upload to S3, and restore to Aurora.
D.Use AWS DMS with ongoing replication from the source MySQL database to Aurora.
AnswerD

DMS supports ongoing replication to keep the target in sync with minimal downtime.

Why this answer

AWS DMS with ongoing replication (change data capture, CDC) is the correct approach because it allows a live migration with minimal downtime. DMS performs a full load of the 100 GB database and then continuously replicates incremental changes from the source MySQL to the target Aurora MySQL until you cut over, keeping the source fully operational throughout the process.

Exam trap

The trap here is that candidates often confuse creating an Aurora Replica (which is an Aurora-only feature) with the ability to replicate from an external MySQL database, or they assume a physical backup can be directly restored into Aurora without understanding the proprietary storage format differences.

How to eliminate wrong answers

Option A is wrong because an Aurora Replica can only be created from an existing Aurora DB cluster, not from an on-premises MySQL database; there is no mechanism to directly create an Aurora Replica from an external source. Option B is wrong because exporting with mysqldump and importing during a maintenance window requires taking the source database offline or severely limiting writes, which contradicts the requirement for minimal downtime. Option C is wrong because taking a physical backup of MySQL and restoring to Aurora is not directly supported; Aurora can only restore from its own native backups or snapshots, and while you can upload MySQL backup files to S3, you cannot restore them into Aurora without additional conversion steps that are not natively available.

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291
MCQhard

Refer to the exhibit. A DBA is monitoring a DMS migration task from on-premises Oracle to Amazon RDS for Oracle. The full load completed successfully with 50 tables. However, the DBA notices that the CDC phase has not started. What is the most likely reason?

A.The task was not configured with CDC enabled
B.The full load encountered errors on some tables
C.The source Oracle database is not generating redo logs
D.The replication task was stopped after the full load completed
AnswerD

The StopDate is set, indicating the task stopped before CDC could begin.

Why this answer

The most likely reason the CDC phase has not started is that the replication task was stopped after the full load completed. In AWS DMS, after the full load finishes, the task must remain in a running state to transition to the CDC phase. If the task is stopped, CDC cannot begin, and the DBA would need to resume or restart the task to capture ongoing changes.

Exam trap

The trap here is that candidates may assume CDC automatically starts after full load, but AWS DMS requires the task to remain in a running state; stopping the task halts the transition to CDC, and this is a common oversight in migration planning.

How to eliminate wrong answers

Option A is wrong because if CDC were not enabled, the task would not have a CDC phase at all, and the full load would simply complete without any expectation of CDC starting; the question states the DBA notices CDC has not started, implying it was expected. Option B is wrong because the full load completed successfully with 50 tables, so there were no errors on tables that would prevent CDC from starting. Option C is wrong because if the source Oracle database were not generating redo logs, CDC would fail or produce errors, but the task would still attempt to start the CDC phase; the absence of redo logs would cause a failure, not a failure to start.

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292
MCQeasy

A developer needs to migrate a 500 GB MongoDB database to Amazon DocumentDB. Which approach will minimize application downtime?

A.Write a custom script to migrate data in batches
B.Export data from MongoDB, upload to S3, and import into DocumentDB
C.Use AWS DMS with ongoing replication from MongoDB to DocumentDB
D.Use AWS DataSync to transfer data files
AnswerC

Minimal downtime with live migration.

Why this answer

AWS DMS with ongoing replication (change data capture) allows you to perform a full load of the existing 500 GB MongoDB data into DocumentDB while continuously replicating new changes from the source. This minimizes application downtime because you can cut over to DocumentDB only after the target is fully synchronized, rather than taking the source offline for the entire migration duration.

Exam trap

The trap here is that candidates often choose Option B (export/import) because it seems straightforward, but they overlook the need for ongoing replication to minimize downtime, which is the key requirement in the question.

How to eliminate wrong answers

Option A is wrong because writing a custom script to migrate data in batches would require the application to be offline or heavily throttled during each batch transfer, and it lacks built-in change data capture to handle ongoing writes, leading to significant downtime. Option B is wrong because exporting data from MongoDB, uploading to S3, and importing into DocumentDB is a one-time bulk operation that does not capture incremental changes; the application must be stopped during the export and import windows to maintain consistency, causing extended downtime. Option D is wrong because AWS DataSync is designed for transferring files over NFS/SMB and does not support MongoDB’s document model or BSON format, making it incapable of migrating a MongoDB database to DocumentDB.

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293
MCQmedium

A company is migrating a 2 TB Oracle database to Amazon Aurora PostgreSQL. The on-premises database is 2 TB and the network link is 1 Gbps. The migration must complete within 48 hours with minimal data loss. The DBA has extracted the schema using AWS SCT and created an Aurora cluster. The DBA now needs to transfer the data. The DBA tried using AWS DMS over the network but estimates it will take 72 hours due to network overhead. The DBA also considered using an AWS Snowball Edge device but is concerned about the time to order and ship the device. Which approach should the DBA take to meet the deadline?

A.Use AWS DMS with change data capture and optimize the network by enabling compression
B.Use AWS S3 to upload the database dump and then load into Aurora
C.Use AWS Snowball Edge to transfer the database dump and then use DMS for change data capture
D.Use AWS DMS to perform a full load and then stop replication, accepting some data loss
AnswerC

Correct. Snowball Edge provides fast bulk transfer, and DMS CDC captures changes during and after the transfer, minimizing data loss and meeting the deadline.

Why this answer

It combines the speed of Snowball Edge for the initial bulk data transfer (2 TB) with AWS DMS for ongoing change data capture (CDC) to minimize data loss. Although ordering and shipping a Snowball device takes time, once received, the data transfer is much faster than over a 1 Gbps network, which would take over 48 hours. DMS alone (option A) is estimated to take 72 hours, exceeding the deadline.

Option B (S3 upload) still relies on network speed and would be too slow. Option D (full load only) abandons CDC and does not meet the minimal data loss requirement.

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294
MCQhard

A company is migrating a 5 TB Oracle database to Amazon RDS for Oracle. The database has several large tables with LOB columns. The migration must have minimal downtime. Which approach should be taken?

A.Use Oracle GoldenGate to replicate data to RDS.
B.Use AWS DMS with LOB support and ongoing replication from Oracle to RDS.
C.Use Oracle Data Pump to export the database and import into RDS.
D.Copy the database files to Amazon S3 and use the rdsadmin.rds_restore_from_s3 procedure.
AnswerB

AWS DMS supports LOBs and can replicate changes continuously, minimizing downtime.

Why this answer

AWS DMS with LOB support and ongoing replication (change data capture, CDC) is the correct approach because it enables a near-zero downtime migration by continuously replicating changes from the source Oracle database to Amazon RDS for Oracle after an initial full load. DMS handles large LOB columns efficiently using its 'Full LOB mode' or 'Limited LOB mode' settings, which are critical for tables with LOB data. The combination of full load + CDC ensures minimal downtime, as the target remains synchronized until cutover.

Exam trap

The trap here is that candidates may choose Oracle GoldenGate (Option A) because it is a well-known replication tool, but the exam expects you to recognize that AWS DMS is the native, fully managed service designed for minimal-downtime migrations to RDS, and GoldenGate introduces unnecessary complexity and cost.

How to eliminate wrong answers

Option A is wrong because Oracle GoldenGate requires additional licensing costs and complex setup, and while it can achieve minimal downtime, it is not the simplest or most cost-effective AWS-native solution for this scenario; AWS DMS is the recommended service for database migrations to RDS. Option C is wrong because Oracle Data Pump is a logical export/import tool that requires the source database to be in a consistent state (often requiring downtime) and cannot provide ongoing replication, so it does not meet the minimal downtime requirement. Option D is wrong because the rdsadmin.rds_restore_from_s3 procedure is used for restoring physical backups (e.g., from RMAN or Oracle Transportable Tablespaces) to RDS, not for migrating a live database with minimal downtime, and it requires the database files to be in a specific format and typically involves downtime during the restore process.

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295
MCQmedium

A company is migrating a 10 TB SQL Server database to Amazon RDS for SQL Server. They need to minimize the migration time and cost. Which approach should they use?

A.Use AWS Snowball Edge to transfer backup files
B.Use AWS Schema Conversion Tool to convert schema and then bulk insert
C.Use AWS DMS with a full load and ongoing replication
D.Use native SQL Server backup to S3 and restore to RDS
AnswerC

Efficient and supports minimal downtime.

Why this answer

AWS DMS with a full load and ongoing replication is the most efficient approach for migrating a 10 TB SQL Server database to Amazon RDS for SQL Server because it performs a one-time full load of the existing data and then continuously replicates ongoing changes, minimizing downtime. DMS handles schema conversion automatically for homogeneous migrations (SQL Server to SQL Server) and supports resumable tasks, which reduces the risk of restarting from scratch on failure. This approach balances speed and cost by using the network for data transfer without the overhead of physical media or manual restore steps.

Exam trap

The trap here is that candidates often assume native backup-to-S3 (Option D) is the fastest because it's a familiar SQL Server tool, but they overlook that DMS's streaming and CDC capabilities minimize downtime and total migration time for large databases, especially when ongoing replication is needed.

How to eliminate wrong answers

Option A is wrong because AWS Snowball Edge is designed for offline data transfer of large datasets (typically >10 TB or limited bandwidth), but for a 10 TB database with reasonable network connectivity, using Snowball introduces significant latency for shipping, handling, and data ingestion, increasing total migration time and cost compared to direct DMS. Option B is wrong because the AWS Schema Conversion Tool (SCT) is used for heterogeneous migrations (e.g., Oracle to SQL Server) to convert schema objects; for a homogeneous SQL Server to SQL Server migration, SCT is unnecessary and adds complexity without benefit, and bulk insert alone does not minimize downtime or handle ongoing replication. Option D is wrong because native SQL Server backup to S3 and restore to RDS requires manual steps, does not support ongoing replication (so it incurs downtime for the final cutover), and is slower for large databases due to the need to upload full backup files to S3 and then restore, which can be network-intensive and less efficient than DMS's streaming approach.

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296
MCQeasy

A company is migrating an on-premises MongoDB database to Amazon DocumentDB (with MongoDB compatibility). Which AWS service can perform the migration with minimal downtime using ongoing replication?

A.AWS Database Migration Service (AWS DMS)
B.Amazon CloudWatch
C.AWS Schema Conversion Tool (AWS SCT)
D.AWS Glue
AnswerA

DMS supports MongoDB to DocumentDB migration with ongoing replication.

Why this answer

AWS DMS supports MongoDB as a source and Amazon DocumentDB as a target, enabling live migration with ongoing replication via change data capture (CDC). This allows the company to migrate with minimal downtime by continuously applying changes from the source MongoDB to the target DocumentDB until cutover.

Exam trap

The trap here is that candidates often confuse AWS SCT's schema conversion capability with full migration including data replication, but SCT does not perform ongoing data sync or CDC, which is essential for minimal-downtime migrations.

How to eliminate wrong answers

Option B is wrong because Amazon CloudWatch is a monitoring and observability service, not a data migration tool; it cannot perform database replication or schema conversion. Option C is wrong because AWS Schema Conversion Tool (AWS SCT) is designed for converting database schemas (e.g., from Oracle to Amazon Aurora) but does not handle ongoing data replication or live migration for MongoDB to DocumentDB. Option D is wrong because AWS Glue is a serverless ETL service for data preparation and transformation, not a database migration service; it lacks the CDC capability needed for minimal-downtime replication of a MongoDB database.

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297
MCQmedium

A company is migrating an on-premises PostgreSQL database to Amazon RDS for PostgreSQL. The database is 2 TB and has a sustained write rate of 150 MB/s. The migration must have minimal downtime. Which AWS service or tool should be used for the initial data load and ongoing replication?

A.Use AWS Database Migration Service (AWS DMS) with full load and ongoing replication
B.Use pg_dump and pg_restore
C.Use AWS Schema Conversion Tool (AWS SCT) to convert schema and AWS DMS for data migration
D.Use AWS S3 Transfer Acceleration to upload data to Amazon S3, then restore to RDS
AnswerA

AWS DMS supports full load and ongoing replication with minimal downtime.

Why this answer

AWS DMS is the correct choice because it supports both a full load of the existing 2 TB database and ongoing change data capture (CDC) to replicate transactions with minimal downtime. DMS can handle sustained write rates of 150 MB/s by using appropriate instance sizing and tuning, and it provides built-in mechanisms for resumable loads and validation, which are critical for a large-scale migration with minimal downtime.

Exam trap

The trap here is that candidates may assume pg_dump/pg_restore can be used with minimal downtime by running them on a replica, but they still require a consistent snapshot and cannot capture ongoing changes, making them unsuitable for near-zero downtime migrations.

How to eliminate wrong answers

Option B is wrong because pg_dump and pg_restore are offline tools that require the source database to be stopped or made read-only during the dump, which does not meet the minimal downtime requirement; they also cannot perform ongoing replication. Option C is wrong because AWS SCT is used for schema conversion when migrating between different database engines (e.g., Oracle to PostgreSQL), but the question specifies a homogeneous migration from on-premises PostgreSQL to RDS for PostgreSQL, so no schema conversion is needed. Option D is wrong because S3 Transfer Acceleration only speeds up uploads to S3, but restoring from S3 to RDS would still require a full offline restore and cannot provide ongoing replication; it also adds unnecessary complexity and latency for a direct database migration.

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298
MCQhard

An IAM policy is attached to a user who is deploying a new RDS instance. What is the effect of this policy on the user's ability to modify an existing production database instance with the identifier 'prod-mydb'?

A.The user cannot modify the production database instance because the Deny statement explicitly denies ModifyDBInstance on production databases.
B.The user can modify the production database instance because the Allow statement grants full access to RDS actions.
C.The user can modify the production database instance if they use the AWS CLI instead of the console.
D.The user cannot modify any database instance because the Deny statement denies ModifyDBInstance on all resources.
AnswerA

Deny overrides Allow, and the resource pattern matches the production database.

Why this answer

The IAM policy includes an explicit Deny statement that denies the `rds:ModifyDBInstance` action when the resource condition matches `arn:aws:rds:*:*:db:prod-mydb`. In IAM, an explicit Deny overrides any Allow, so even though the Allow statement grants full RDS access, the Deny takes precedence and blocks modification of the production database instance with identifier 'prod-mydb'.

Exam trap

The trap here is that candidates often assume an Allow statement with full access will override a Deny, but AWS IAM explicitly prioritizes Deny over Allow, and the Deny's resource condition restricts the effect to only the named production database, not all databases.

How to eliminate wrong answers

Option B is wrong because it ignores the explicit Deny statement; in IAM, an explicit Deny always overrides an Allow, so the Allow statement does not grant the ability to modify the specified production database. Option C is wrong because IAM policies are service-agnostic and apply equally to the AWS Management Console, CLI, and SDKs; the Deny statement blocks the action regardless of the interface used. Option D is wrong because the Deny statement is scoped to the specific resource `arn:aws:rds:*:*:db:prod-mydb`, not to all database instances; the user can still modify other RDS instances that do not match that resource ARN.

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299
MCQmedium

Refer to the exhibit. A company is migrating an on-premises database to Amazon RDS for MySQL. During a test migration, the DMS task fails with the error shown. The source database is 500 GB and the target RDS instance has 500 GB allocated storage. What should be done to resolve this error and complete the migration?

A.Increase the DB instance class to a larger size
B.Increase the DMS task's allocated storage
C.Reduce the size of the source database
D.Enable storage autoscaling on the RDS instance
AnswerD

Autoscaling will automatically increase storage as needed.

Why this answer

The error indicates that the target RDS instance ran out of storage during the migration. Enabling storage autoscaling allows RDS to automatically increase storage when free space is low, preventing the migration from failing due to insufficient disk space. This is the correct resolution because the source database is 500 GB and the target has exactly 500 GB allocated, leaving no room for temporary data or logs during the migration.

Exam trap

The trap here is that candidates confuse storage allocation with instance class or DMS storage, thinking performance upgrades or DMS settings will fix a disk space issue, when the real problem is simply that the target RDS instance needs more storage capacity.

How to eliminate wrong answers

Option A is wrong because increasing the DB instance class (CPU/memory) does not increase storage capacity; it addresses performance, not disk space. Option B is wrong because DMS tasks do not have allocated storage; DMS uses replication instances with their own storage, but the error is about the target RDS instance's storage, not DMS storage. Option C is wrong because reducing the source database size is unnecessary and impractical; the migration should handle the full dataset, and the issue is insufficient target storage, not source size.

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300
MCQmedium

A company is migrating a 3 TB PostgreSQL database from on-premises to Amazon Aurora PostgreSQL. They need to minimize downtime and ensure that the migration is completed within a maintenance window. Which approach should they use?

A.Use AWS DMS with full load and ongoing replication (CDC)
B.Use AWS SCT to convert the schema and then migrate data
C.Use pg_dump to export the database and pg_restore to import into Aurora
D.Take a file system snapshot and restore to Aurora
AnswerA

DMS with CDC supports minimal downtime by replicating changes.

Why this answer

AWS DMS with full load and ongoing replication (CDC) is the correct approach because it allows you to perform an initial full load of the 3 TB database while continuously capturing changes from the source PostgreSQL using logical replication (via the pglogical extension or native slot-based replication). This minimizes downtime by keeping the target Aurora PostgreSQL nearly synchronized, and you can switch over during a maintenance window with only a brief outage to apply any final lag.

Exam trap

The trap here is that candidates often choose pg_dump/pg_restore (Option C) because it is a familiar tool, but they overlook the requirement to minimize downtime, which CDC-based replication uniquely addresses.

How to eliminate wrong answers

Option B is wrong because AWS SCT is used for schema conversion (e.g., from Oracle or SQL Server to Aurora PostgreSQL), not for migrating data from PostgreSQL to PostgreSQL, and it does not provide ongoing replication to minimize downtime. Option C is wrong because pg_dump/pg_restore is a logical backup and restore method that requires the source database to be offline or read-only during the dump, causing significant downtime for a 3 TB database, and it does not support continuous replication. Option D is wrong because file system snapshots are not compatible with Aurora PostgreSQL; Aurora uses a distributed storage layer and cannot ingest raw file system snapshots from on-premises PostgreSQL.

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