Storage vs memory usage in Blockchain / Solidity - Hands-On Comparison

Storage vs Memory Usage in a Simple Blockchain

📖 Scenario: You are building a simple blockchain to understand how data is stored permanently (storage) versus temporarily (memory) during transactions.

🎯 Goal: Create a small blockchain where blocks are stored permanently in a list (storage), and transactions are held temporarily in a memory list before being added to a block.

📋 What You'll Learn

Create a list called blockchain to store blocks permanently.

Create a list called memory_pool to hold transactions temporarily.

Add transactions to memory_pool.

When memory_pool reaches 2 transactions, create a block and add it to blockchain.

Print the blockchain to show stored blocks.

💡 Why This Matters

🌍 Real World

Blockchains store data permanently in blocks (storage), but transactions first live temporarily in memory pools before being added to blocks.

💼 Career

Understanding storage vs memory in blockchain helps in designing efficient decentralized applications and smart contracts.

1

Create the blockchain storage

Create an empty list called blockchain to store blocks permanently.

Blockchain / Solidity

# Create an empty list called blockchain
# Your code here

Need a hint?

Use blockchain = [] to create an empty list.

2

Create the memory pool for transactions

Create an empty list called memory_pool to hold transactions temporarily.

Blockchain / Solidity

blockchain = []
# Create an empty list called memory_pool
# Your code here

Need a hint?

Use memory_pool = [] to create an empty list.

3

Add transactions and create blocks

Add these two transactions 'tx1' and 'tx2' to memory_pool. Then, when memory_pool has 2 transactions, create a block dictionary with key 'transactions' and value memory_pool. Append this block to blockchain and clear memory_pool.

Blockchain / Solidity

blockchain = []
memory_pool = []
# Add 'tx1' and 'tx2' to memory_pool
# When memory_pool has 2 transactions, create a block and add it to blockchain
# Clear memory_pool after adding the block
# Your code here

Need a hint?

Use append() to add transactions. Check length with len(). Use copy() to avoid reference issues.

4

Print the blockchain storage

Print the blockchain list to show the stored blocks.

Blockchain / Solidity

blockchain = []
memory_pool = []
memory_pool.append('tx1')
memory_pool.append('tx2')
if len(memory_pool) == 2:
    block = {'transactions': memory_pool.copy()}
    blockchain.append(block)
    memory_pool.clear()
# Print the blockchain list
# Your code here

Need a hint?

Use print(blockchain) to display the stored blocks.