Database choice for toy blockchain in Go
Jun 17, 2023
2 min read
This blog post is one of the many blog posts in the series of blog posts about my toy blockchain in Go. In order to understand Ethereum, I have decided to build one from scratch. Will use go-ethereum as a reference.
In order to provide state persistence, the Ethereum spec defines the use of database to store the world state. the For storing the world state of the blockchin (which is just a very large merkel patrichia tree), a highly performant and fast key-value store is required. There are many databases which can be used for this purpose.
In this blog post, I will be discussing the database choice for my toy blockchain in Go. I will be discussing the following databases:
BadgerDB
The database is built in Go and is optimized for SSDs. It is a key-value store and is very fast. It is also ACID compliant. It is also used by Dgraph.
There is no issue as such for me to not pick this database. But I want to explore other databases as well. Also, I think this db would be an overkill for my toy blockchain.
etcd
etcd is a distributed key-value store. It is built in Go and is used by cloud native softwares such as Kubernetes and Docker.
The main issue which prevented me from using this db was that it’s installation was not that simple. Some of the dependencies were only complied for 32-bit systems causing problems.
LevelDB
Built in C++ and used by Google Chrome. It is also a key-value store. It is also very fast. It is also used by Ethereum.
The most popular implementation of ethereum is the go-ethereum or geth. When I was reading the code of geth, I found that they are using LevelDB but since the codebase is in Go, they are using the wrapper of LevelDB in Go - https://github.com/syndtr/goleveldb
Although this is an old implementation, when I tried it, al its features were working fine. I think I will be using this database for my toy blockchain.
Conclusion
Although I have decided to go ahead with LevelDB, I will be exploring other databases as well if the former ends up being a bottleneck. I will be writing a blog post about the implementation of LevelDB in my toy blockchain.