Ethereum Blockchain Explorers – Complete List and Overview

Data structures are stored in Merkle Patricia tries (read this and this), usually inside a LevelDB store. The chaindata is exactly that.

I think the structure might slightly depend on the actual node implementation?

Here are two of the trie implementations, could be a good starting point:

• in Go (geth): https://github.com/ethereum/go-ethereum/tree/master/trie
• in Javascript: https://github.com/ethereumjs/merkle-patricia-tree

Once that is understood, you will need to look up the data structures sent over the network, especially blocks, transactions, accounts and storage. Accounts refer to both externally owned and contract accounts, the latter with contract code. Storage refers to contract storage.

Back to the point of data analysis

You might be better off building a traditional NoSQL or SQL database if you want to have quick lookups about any transactions done by an account or contract. What the chaindata is optimised for is validating transactions and maintaining a valid state, and not so for historical lookups.

I couldn't find what I was after so I did my own: