First table creation in DynamoDB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

What is the output of this DynamoDB table creation command?

Consider this AWS CLI command to create a DynamoDB table named 'Books' with 'ISBN' as the partition key. What will be the result if the command runs successfully?

DynamoDB

aws dynamodb create-table --table-name Books --attribute-definitions AttributeName=ISBN,AttributeType=S --key-schema AttributeName=ISBN,KeyType=HASH --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

A Syntax error due to missing sort key definition.

B Table 'Books' is created but with default throughput of 1 read and 1 write unit.

C Table 'Books' is created with 'ISBN' as the partition key and provisioned throughput of 5 read and 5 write units.

D Error because 'ISBN' attribute type 'S' is invalid.

💡 Hint

Remember that DynamoDB requires at least a partition key and you can specify throughput explicitly.

The command correctly defines a table named 'Books' with 'ISBN' as the partition key (HASH) of type string (S). Provisioned throughput is set to 5 read and 5 write units. No sort key is required.

📝 Syntax

intermediate

Which option contains a syntax error in DynamoDB table creation?

Identify the option that will cause a syntax error when creating a DynamoDB table with a partition key 'UserId' of type string.

A aws dynamodb create-table --table-name Users --attribute-definitions AttributeName=UserId,AttributeType=S --key-schema AttributeName=UserId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=1,WriteCapacityUnits=1

B aws dynamodb create-table --table-name Users --attribute-definitions AttributeName=UserId,AttributeType=S --key-schema AttributeName=UserId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

C aws dynamodb create-table --table-name Users --attribute-definitions AttributeName=UserId,AttributeType=S --key-schema AttributeName=UserId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=10

D aws dynamodb create-table --table-name Users --attribute-definitions AttributeName=UserId,AttributeType=String --key-schema AttributeName=UserId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=1,WriteCapacityUnits=1

💡 Hint

Check the attribute type values allowed by DynamoDB.

DynamoDB attribute types are single letters like 'S' for string, not full words like 'String'. Option D uses 'String' which is invalid and causes a syntax error.

🧠 Conceptual

advanced

Why is a sort key optional when creating a DynamoDB table?

When creating a DynamoDB table, you can define a partition key alone or both a partition key and a sort key. Why might you choose to omit the sort key?

A Because DynamoDB requires a sort key only for tables with more than 1000 items.

B Because a partition key alone uniquely identifies each item, so a sort key is not always necessary.

C Because the sort key is only used for indexing and does not affect uniqueness.

D Because the sort key is deprecated and no longer supported in DynamoDB.

💡 Hint

Think about how DynamoDB uses keys to identify items.

The partition key uniquely identifies each item in the table. A sort key is optional and used to organize items with the same partition key. It is not mandatory for uniqueness.

❓ query_result

advanced

What is the output of this DynamoDB table creation with a composite key?

This command creates a table 'Orders' with 'OrderId' as partition key and 'OrderDate' as sort key. What will be the result?

DynamoDB

aws dynamodb create-table --table-name Orders --attribute-definitions AttributeName=OrderId,AttributeType=S AttributeName=OrderDate,AttributeType=S --key-schema AttributeName=OrderId,KeyType=HASH AttributeName=OrderDate,KeyType=RANGE --provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=10

A Table 'Orders' is created with composite primary key (OrderId, OrderDate) and provisioned throughput of 10 read and 10 write units.

B Error due to missing comma between attribute definitions.

C Table 'Orders' is created but only with 'OrderId' as key, ignoring 'OrderDate'.

D Syntax error because provisioned throughput values are too high.

💡 Hint

Check how multiple attributes and keys are defined in the command.

The command correctly defines two attributes and a composite key with partition and sort keys. Provisioned throughput is valid. The table will be created as expected.

🔧 Debug

expert

Why does this DynamoDB table creation command fail?

This command attempts to create a table 'Employees' with 'EmployeeId' as partition key. Why does it fail?

DynamoDB

aws dynamodb create-table --table-name Employees --attribute-definitions AttributeName=EmployeeId,AttributeType=N --key-schema AttributeName=EmployeeId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=0,WriteCapacityUnits=5

A Because ReadCapacityUnits cannot be zero; it must be at least 1.

B Because attribute type 'N' is invalid for partition key.

C Because the key schema is missing a sort key.

D Because WriteCapacityUnits cannot be less than ReadCapacityUnits.

💡 Hint

Check the allowed values for provisioned throughput.

DynamoDB requires ReadCapacityUnits and WriteCapacityUnits to be at least 1. Setting ReadCapacityUnits to 0 causes the command to fail.

Practice

1. What is the minimum required element when creating a DynamoDB table?

easy

A. Table name and global secondary index

B. Table name and secondary index

C. Table name and primary key

D. Provisioned throughput only

Solution

1. Step 1: Understand DynamoDB table basics

   Every DynamoDB table must have a unique name and a primary key to identify items.

2. Step 2: Identify required elements for creation

   Secondary indexes and throughput settings are optional or have defaults, but primary key and table name are mandatory.

3. Final Answer:

   Table name and primary key -> Option C

4. Quick Check:

   Minimum required = Table name + primary key [OK]

Hint: Always specify table name and primary key first [OK]

Common Mistakes:

• Forgetting to define the primary key
• Confusing secondary index as mandatory
• Omitting the table name

2. Which AWS CLI command correctly creates a DynamoDB table named Users with a primary key UserId of type string?

easy

A. aws dynamodb create-table --table-name Users --attribute-definitions AttributeName=UserId,AttributeType=S --key-schema AttributeName=UserId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

B. aws dynamodb create-table --name Users --key UserId --type S

C. aws dynamodb create-table --table Users --primary-key UserId String

D. aws dynamodb make-table --table-name Users --key UserId --attribute-type S

Solution

1. Step 1: Check AWS CLI syntax for create-table

   The correct command uses 'aws dynamodb create-table' with options: --table-name, --attribute-definitions, --key-schema, and --provisioned-throughput.

2. Step 2: Verify option correctness

   aws dynamodb create-table --table-name Users --attribute-definitions AttributeName=UserId,AttributeType=S --key-schema AttributeName=UserId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5 correctly specifies attribute name and type, key schema with HASH key, and provisioned throughput. Others use invalid or incomplete syntax.

3. Final Answer:

   aws dynamodb create-table --table-name Users --attribute-definitions AttributeName=UserId,AttributeType=S --key-schema AttributeName=UserId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5 -> Option A

4. Quick Check:

   Correct CLI syntax = aws dynamodb create-table --table-name Users --attribute-definitions AttributeName=UserId,AttributeType=S --key-schema AttributeName=UserId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5 [OK]

Hint: Use full AWS CLI syntax with attribute-definitions and key-schema [OK]

Common Mistakes:

• Using wrong command name like make-table
• Missing attribute-definitions or key-schema
• Incorrect option names like --name instead of --table-name

3. Given this AWS CLI command, what will be the primary key type of the table?

aws dynamodb create-table --table-name Products --attribute-definitions AttributeName=ProductId,AttributeType=N --key-schema AttributeName=ProductId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=1,WriteCapacityUnits=1

medium

A. String

B. Binary

C. Boolean

D. Number

Solution

1. Step 1: Identify attribute type in attribute-definitions

   The attribute ProductId is defined with AttributeType=N, which means Number.

2. Step 2: Confirm key schema uses ProductId as HASH key

   The key schema uses ProductId as the partition key, so its type is Number.

3. Final Answer:

   Number -> Option D

4. Quick Check:

   AttributeType=N means Number [OK]

Hint: AttributeType=N means Number, S means String [OK]

Common Mistakes:

• Confusing N with String type
• Ignoring attribute-definitions
• Assuming default type is String

4. You run this command but get an error:

aws dynamodb create-table --table-name Orders --attribute-definitions AttributeName=OrderId --key-schema AttributeName=OrderId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=1,WriteCapacityUnits=1

What is the likely cause?

medium

A. Missing KeyType in key-schema

B. Missing AttributeType in attribute-definitions

C. Provisioned throughput values are too low

D. Table name is invalid

Solution

1. Step 1: Check attribute-definitions syntax

   The attribute-definitions must include AttributeType (S, N, or B). Here, AttributeType is missing.

2. Step 2: Verify other parts

   KeyType is present, throughput values are valid, and table name is valid. So the error is due to missing AttributeType.

3. Final Answer:

   Missing AttributeType in attribute-definitions -> Option B

4. Quick Check:

   AttributeType required in attribute-definitions [OK]

Hint: Always specify AttributeType with AttributeName [OK]

Common Mistakes:

• Omitting AttributeType in attribute-definitions
• Confusing KeyType with AttributeType
• Assuming throughput values cause error

5. You want to create a DynamoDB table named Employees with a composite primary key: EmployeeId (string) as partition key and Department (string) as sort key. Which command correctly creates this table?

hard

A. aws dynamodb create-table --table-name Employees --attribute-definitions AttributeName=EmployeeId,AttributeType=S AttributeName=Department,AttributeType=S --key-schema AttributeName=EmployeeId,KeyType=HASH AttributeName=Department,KeyType=RANGE --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

B. aws dynamodb create-table --table-name Employees --attribute-definitions EmployeeId=S Department=S --key-schema EmployeeId=HASH Department=RANGE --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

C. aws dynamodb create-table --table Employees --attributes EmployeeId:string Department:string --keys EmployeeId:partition Department:sort --throughput 5 5

D. aws dynamodb create-table --table-name Employees --attribute-definitions AttributeName=EmployeeId,AttributeType=S --key-schema AttributeName=EmployeeId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

Solution

1. Step 1: Define attribute-definitions for both keys

   Both EmployeeId and Department must be defined with AttributeType=S.

2. Step 2: Define key-schema with HASH and RANGE keys

   EmployeeId is partition key (HASH), Department is sort key (RANGE).

3. Step 3: Check command syntax

   aws dynamodb create-table --table-name Employees --attribute-definitions AttributeName=EmployeeId,AttributeType=S AttributeName=Department,AttributeType=S --key-schema AttributeName=EmployeeId,KeyType=HASH AttributeName=Department,KeyType=RANGE --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5 correctly uses --attribute-definitions and --key-schema with proper syntax and throughput.

4. Final Answer:

   aws dynamodb create-table --table-name Employees --attribute-definitions AttributeName=EmployeeId,AttributeType=S AttributeName=Department,AttributeType=S --key-schema AttributeName=EmployeeId,KeyType=HASH AttributeName=Department,KeyType=RANGE --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5 -> Option A

5. Quick Check:

   Composite key needs both keys in attribute-definitions and key-schema [OK]

Hint: List all keys in attribute-definitions and key-schema [OK]

Common Mistakes:

• Defining only partition key without sort key
• Incorrect key-schema syntax
• Missing attribute definition for sort key