When Scan is acceptable in DynamoDB - Mini Project: Build & Apply

When Scan is Acceptable in DynamoDB

📖 Scenario: You are managing a small DynamoDB table that stores information about books in a local library. The table is small and you want to understand when it is okay to use a Scan operation instead of a Query.

🎯 Goal: Build a simple DynamoDB setup and write a Scan operation that is acceptable because the table is small and you want to retrieve all items.

📋 What You'll Learn

Create a DynamoDB table data structure with exactly 3 book items

Add a variable to hold the table name

Write a Scan operation to retrieve all items from the table

Add a final configuration to limit the scan to 3 items

💡 Why This Matters

🌍 Real World

In small DynamoDB tables or during development, using Scan to get all items is acceptable because the data size is small and performance impact is minimal.

💼 Career

Understanding when Scan is acceptable helps database developers and cloud engineers optimize DynamoDB usage and avoid costly or slow operations in production.

1

Create a DynamoDB table data structure

Create a variable called books_table that is a list of dictionaries. Add exactly these 3 items with keys BookID, Title, and Author: {'BookID': '1', 'Title': 'The Hobbit', 'Author': 'J.R.R. Tolkien'}, {'BookID': '2', 'Title': '1984', 'Author': 'George Orwell'}, {'BookID': '3', 'Title': 'To Kill a Mockingbird', 'Author': 'Harper Lee'}.

DynamoDB

# Create the books_table list with 3 book dictionaries
# Your code here

Need a hint?

Use a list with three dictionaries exactly as shown.

2

Add a variable for the table name

Create a variable called table_name and set it to the string 'LibraryBooks'.

DynamoDB

books_table = [
    {'BookID': '1', 'Title': 'The Hobbit', 'Author': 'J.R.R. Tolkien'},
    {'BookID': '2', 'Title': '1984', 'Author': 'George Orwell'},
    {'BookID': '3', 'Title': 'To Kill a Mockingbird', 'Author': 'Harper Lee'}
]

# Create the table_name variable
# Your code here

Need a hint?

Set the variable table_name to the exact string 'LibraryBooks'.

3

Write a Scan operation to retrieve all items

Create a variable called scan_result and set it to a dictionary with a key Items whose value is the books_table list. This simulates scanning the entire table to get all items.

DynamoDB

books_table = [
    {'BookID': '1', 'Title': 'The Hobbit', 'Author': 'J.R.R. Tolkien'},
    {'BookID': '2', 'Title': '1984', 'Author': 'George Orwell'},
    {'BookID': '3', 'Title': 'To Kill a Mockingbird', 'Author': 'Harper Lee'}
]

table_name = 'LibraryBooks'

# Create scan_result dictionary with Items key set to books_table
# Your code here

Need a hint?

Set scan_result to a dictionary with key 'Items' and value books_table.

4

Limit the Scan to 3 items

Add a variable called limit and set it to the number 3. Then add this limit as a key-value pair in the scan_result dictionary with key Limit.

DynamoDB

books_table = [
    {'BookID': '1', 'Title': 'The Hobbit', 'Author': 'J.R.R. Tolkien'},
    {'BookID': '2', 'Title': '1984', 'Author': 'George Orwell'},
    {'BookID': '3', 'Title': 'To Kill a Mockingbird', 'Author': 'Harper Lee'}
]

table_name = 'LibraryBooks'

scan_result = {'Items': books_table}

# Create limit variable and add it to scan_result dictionary
# Your code here

Need a hint?

Set limit to 3 and add it to scan_result with key 'Limit'.