The best way to learn is to teach.
There are questions from the floor every time I conduct a training. Some questions prompted me into further research about the topic. I was conducting training about blockchain to 50 over computer science students of University of the Philippines Diliman last Saturday (23rd February 2019). A tiny girl with long hair, in a white tee and with a pair of glasses (the third one to my left in the picture) asked a good question. “Since all the data written to blockchain is immutable, wouldn’t the database get very huge?”
My answer? “Yes. However, I won’t worry much about that.” Why would I say that? The size of a blockchain would grow bigger in a faster pace when it is active with lots of transactions to be recorded. (Check out the Bitcoin Blockchain size @ https://www.blockchain.com/en/charts/blocks-size?timespan=all, you can see that the curve is expanding exponentially only after 2013 when people started to explore and use Bitcoin.) If there are not many transactions going on for the blockchain, the growth of the blockchain in size will be slow. Hence, I would worry more about blockchain adoption rather than the storage for the blockchain. If a blockchain becomes so popular and active that keeping a full node would require big storage size, that would be a good problem to have, in my opinion.
Let’s go back to year 2000 when flash drive was being introduced. It was only 128MB capacity for one flash drive. Fast forward almost 20 years later, the capacity for a flash drive is now 1 terabyte and more, 1,000,000 times of the first version of flash drive. As for Bitcoin, in 10 years time, its blockchain size has grown 205,000 times.
It is the problems we have that push us to improve on our skills and technologies and those are the motivations for human kind to progress. There will always be technology that is trying to overtake another. There have been many studies and researches going on to tackle the above mentioned issues of blockchains. For example, Lightning Network of Bitcoin, historical-chain-pruning of Ethereum, and the 2-tier architecture that NEM adopts, all are in one way or another working to reduce the blockchain size.
As of the time this article is written, the blokchain size of Bitcoin is 205.44GB after 10 years since it Genesis block; Ethereum has grown to 130.42GB after almost 4 years since October 2015; NEM has 2.8GB after 4 years. Ethereum runs on EVM hence the blockchain size has been growing exponentially. The growth rate of NEM’s blockchain size is much lower due to 2-layer architecture that it adopts.
A note on University of the Philippines Diliman. It is the top university in the Philippines and rank within 500 in the world. This workshop is to prepare the students for Hackathon that is organised by Center for Student Innovations (CSI) led by Jacob, Ryan and Lance.
