On-demand backups in DynamoDB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

What is the output of the backup status query?

You run the following AWS CLI command to list backups for a DynamoDB table named Users.

aws dynamodb list-backups --table-name Users

What key in the JSON output tells you the status of each backup?

A "BackupArn"

B "BackupCreationDateTime"

C "BackupStatus"

D "BackupName"

💡 Hint

Look for the key that describes if the backup is completed or in progress.

The key "BackupStatus" in the output JSON shows the status of each backup, such as 'CREATING' or 'AVAILABLE'.

🧠 Conceptual

intermediate

Which statement about on-demand backups is true?

Consider these statements about DynamoDB on-demand backups. Which one is correct?

A On-demand backups can be created without impacting table performance.

B On-demand backups automatically delete after 7 days.

C On-demand backups require the table to be in read-only mode.

D On-demand backups cannot be created for global tables.

💡 Hint

Think about how backups affect normal table operations.

On-demand backups in DynamoDB are designed to be created without affecting the table's availability or performance.

📝 Syntax

advanced

Which AWS CLI command correctly creates an on-demand backup?

You want to create an on-demand backup of a DynamoDB table named Orders. Which command is correct?

A aws dynamodb backup-table --table Orders --name OrdersBackup1

B aws dynamodb make-backup --table-name Orders --backup-name OrdersBackup1

C aws dynamodb start-backup --table Orders --backup OrdersBackup1

D aws dynamodb create-backup --table-name Orders --backup-name OrdersBackup1

💡 Hint

Check the exact AWS CLI command syntax for creating backups.

The correct AWS CLI command to create an on-demand backup is 'create-backup' with parameters --table-name and --backup-name.

❓ optimization

advanced

How to minimize costs when using on-demand backups?

You have many on-demand backups for a DynamoDB table. Which practice helps reduce storage costs?

A Delete old backups that are no longer needed.

B Create backups more frequently to have more restore points.

C Keep all backups indefinitely for safety.

D Use on-demand backups only during peak hours.

💡 Hint

Think about how backup storage costs accumulate.

Deleting old backups that are no longer needed helps reduce storage costs because backups consume storage space billed by AWS.

🔧 Debug

expert

Why does this backup creation command fail?

You run this command:

aws dynamodb create-backup --table-name Customers --backup-name

But it returns an error. What is the cause?

A The table name 'Customers' does not exist.

B The --backup-name parameter is missing a value.

C The AWS CLI version does not support create-backup.

D The command requires --region parameter.

💡 Hint

Check if all required parameters have values.

The error occurs because the --backup-name parameter is given without a value, which is required.

Practice

1. What is the main purpose of on-demand backups in DynamoDB?

easy

A. To delete old data from the table

B. To automatically scale the table capacity

C. To encrypt data during transfer

D. To save a copy of your table data at any time for recovery

Solution

1. Step 1: Understand what on-demand backups do

   On-demand backups let you save your DynamoDB table data whenever you want.

2. Step 2: Identify the main purpose

   The main goal is to protect data and allow recovery if needed.

3. Final Answer:

   To save a copy of your table data at any time for recovery -> Option D

4. Quick Check:

   On-demand backups = save data anytime [OK]

Hint: Backups save data copies for recovery anytime [OK]

Common Mistakes:

• Confusing backups with scaling features
• Thinking backups delete data
• Mixing encryption with backup purpose

2. Which AWS CLI command is used to create an on-demand backup of a DynamoDB table?

easy

A. aws dynamodb backup-table

B. aws dynamodb start-backup

C. aws dynamodb create-backup

D. aws dynamodb save-backup

Solution

1. Step 1: Recall the correct AWS CLI command for backups

   The official command to create an on-demand backup is create-backup.

2. Step 2: Match the command with options

   Only aws dynamodb create-backup matches the exact AWS CLI syntax.

3. Final Answer:

   aws dynamodb create-backup -> Option C

4. Quick Check:

   Command to create backup = create-backup [OK]

Hint: Remember 'create-backup' for making backups [OK]

Common Mistakes:

• Using incorrect command names like start-backup
• Confusing backup commands with table creation
• Adding extra words not in AWS CLI syntax

3. What will happen if you run this AWS CLI command?

aws dynamodb create-backup --table-name Users --backup-name UsersBackup1

medium

A. It creates a backup named 'UsersBackup1' of the 'Users' table

B. It deletes the 'Users' table

C. It lists all backups of the 'Users' table

D. It restores the 'Users' table from a backup

Solution

1. Step 1: Analyze the command parameters

   The command uses create-backup with a table name and backup name.

2. Step 2: Understand the command effect

   This command creates a new backup of the specified table with the given backup name.

3. Final Answer:

   It creates a backup named 'UsersBackup1' of the 'Users' table -> Option A

4. Quick Check:

   create-backup + table + backup name = new backup [OK]

Hint: create-backup command makes a new backup copy [OK]

Common Mistakes:

• Thinking it deletes or restores the table
• Confusing create-backup with list-backups
• Assuming it modifies table data

4. You tried to create a backup with this command:

aws dynamodb create-backup --table-name Orders

Why did it fail?

medium

A. Table name 'Orders' does not exist

B. Missing the required --backup-name parameter

C. You need to use 'start-backup' instead of 'create-backup'

D. Backups are not supported for DynamoDB tables

Solution

1. Step 1: Check the command syntax

   The command is missing the --backup-name parameter which is required.

2. Step 2: Understand AWS CLI requirements

   Without a backup name, the command cannot create a backup and will fail.

3. Final Answer:

   Missing the required --backup-name parameter -> Option B

4. Quick Check:

   create-backup needs backup name [OK]

Hint: Always include --backup-name when creating backups [OK]

Common Mistakes:

• Assuming table name alone is enough
• Using wrong command like start-backup
• Believing backups are unsupported

5. You want to create an on-demand backup for a table named 'Products' and then restore it if needed. Which sequence of AWS CLI commands is correct?

hard

A. aws dynamodb create-backup --table-name Products --backup-name ProdBackup1aws dynamodb restore-table-from-backup --target-table-name ProductsRestored --backup-arn

B. aws dynamodb backup-table --table-name Productsaws dynamodb restore-table --table-name ProductsRestored

C. aws dynamodb start-backup --table Productsaws dynamodb recover-table --table ProductsRestored

D. aws dynamodb create-backup --table Products --backup-name ProdBackup1aws dynamodb restore-backup --table ProductsRestored --backup-name ProdBackup1

Solution

1. Step 1: Identify correct backup creation command

   The correct command to create a backup is create-backup with table and backup names.

2. Step 2: Identify correct restore command

   To restore, use restore-table-from-backup with target table name and backup ARN.

3. Step 3: Verify options

   Only aws dynamodb create-backup --table-name Products --backup-name ProdBackup1
   aws dynamodb restore-table-from-backup --target-table-name ProductsRestored --backup-arn uses the correct commands and parameters for both backup and restore.

4. Final Answer:

   Use create-backup then restore-table-from-backup with backup ARN -> Option A

5. Quick Check:

   Backup with create-backup, restore with restore-table-from-backup [OK]

Hint: Backup with create-backup, restore with restore-table-from-backup [OK]

Common Mistakes:

• Using wrong commands like start-backup or backup-table
• Missing backup ARN in restore command
• Confusing restore parameters