Why data location affects cost in Blockchain / Solidity - Visual Breakdown

Concept Flow - Why data location affects cost

User wants to store data

↓

Choose data location

↓

Check storage cost per location

↓

Calculate total cost

↓

Decide to store or not

↓

Store data

↓

Cancel storage

Data location affects cost because different blockchain storage options charge differently based on where data is stored.

Execution Sample

Blockchain / Solidity

storage_costs = {"on_chain": 10, "off_chain": 2}
data_size = 5
location = "on_chain"
total_cost = storage_costs[location] * data_size
print(total_cost)

Calculates total cost to store data based on chosen location and data size.

Execution Table

Step	Variable	Value	Action	Output
1	storage_costs	{"on_chain": 10, "off_chain": 2}	Define cost per unit data
2	data_size	5	Define data size to store
3	location	"on_chain"	Choose data location
4	total_cost	storage_costs["on_chain"] * 5	Calculate total cost	50
5	print(total_cost)		Output total cost	50

💡 Calculation done and cost output printed

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
storage_costs	undefined	{"on_chain": 10, "off_chain": 2}	{"on_chain": 10, "off_chain": 2}	{"on_chain": 10, "off_chain": 2}	{"on_chain": 10, "off_chain": 2}	{"on_chain": 10, "off_chain": 2}
data_size	undefined	undefined	5	5	5	5
location	undefined	undefined	undefined	"on_chain"	"on_chain"	"on_chain"
total_cost	undefined	undefined	undefined	undefined	50	50

Key Moments - 2 Insights

Why does choosing 'on_chain' cost more than 'off_chain'?

Because 'on_chain' storage cost per unit is 10, higher than 'off_chain' which is 2, as shown in execution_table step 4 calculation.

What happens if data_size changes?

Total cost changes proportionally since total_cost = cost_per_unit * data_size, as seen in step 4.

Visual Quiz - 3 Questions

Look at the execution_table at step 4, what is the total_cost value?

A 10

B 50

C 5

D 2

💡 Hint

Check the 'Value' column for total_cost at step 4 in execution_table.

At which step is the data location chosen?

A Step 2

B Step 1

C Step 3

D Step 4

💡 Hint

Look for the step where 'location' variable is assigned in execution_table.

If data_size was 10 instead of 5, what would total_cost be at step 4?

A 100

B 50

C 20

D 10

💡 Hint

Multiply storage_costs['on_chain'] (10) by new data_size (10) as in step 4 calculation.

Concept Snapshot

Data location affects cost because different storage options charge differently.
Cost = cost_per_unit * data_size.
On-chain storage is usually more expensive than off-chain.
Choosing location impacts total cost directly.
Always calculate cost before storing data.

Full Transcript

This visual execution shows how data location affects cost in blockchain storage. First, storage costs per location are defined. Then, data size and location are chosen. The total cost is calculated by multiplying cost per unit by data size. Finally, the cost is printed. On-chain storage costs more per unit than off-chain, so total cost depends on location and data size.