Database diagram

Blocks

The Blocks table contains bare block information (timestamp, witness …)

Transactions

Each block can contains Transactions
Depending on each transaction type, the associated transaction’s data is stored in the related table.

Accounts

The Accounts table is a non-transactional table and contains a list of all accounts and related information resulting from activity of accounts on the blockchain

Comments

The Comments table is a non-transactional table and contains all posts and comments and the related information resulting from activity related to posts on the blockchain (updates, votes, …)

Followers

The Followers table is a non-transactional table which enables to know who is following who.

Reblogs

The Reblogs table is a non-transactional table which enables to know who “resteemed” which post or comment.

Witnesses

The Witnesses table is a non-transactional table which contains a list of all witnesses and related information.

Virtual Operations

Virtual operations are operations resulting from the activity of the blockchain but, unlike transactions, they are not initiated by users.

More information about virtual operations tables (VO…) can be found here