The cardano-db-sync component consists of a set of components:
cardano-dbwhich defines common data types and functions used by any application that needs to interact with the data base from Haskell. In particular, it defines the database schema.cardano-db-syncwhich acts as a Cardano node, following the chain and inserting data from the chain into a PostgreSQL database.cardano-db-sync-extendedis a relatively simple extension tocardano-db-syncwhich maintains an extra table containing epoch data.
The two versions cardano-db-sync and cardano-db-sync-extended are fully compatible and use
identical database schema. The only difference is that the extended version maintains an Epoch
table. The non-extended version will still create this table but will not maintain it.
The db-sync node is written in a highly modular fashion to allow it to be as flexible as possible.
The cardano-db-sync node connects to a locally running cardano-node (ie one connected to other
nodes in the Cardano network over the internet with TCP/IP) using a Unix domain socket, retrieves
blocks and stores parts of each block in a local PostgreSQL database. The database does not store
things like cryptographic signatures but does store enough information to follow the chain of
blocks and look at the transactions within blocks.
The PostgreSQL database is designed to be accessed in a read-only fashion from other applications. The database schema is highly normalised which helps prevent data inconsistencies (specifically with the use of foreign keys from one table to another). More user friendly database queries can be implemented using Postgres Views to implement joins between tables.
- BuildingRunning: Building and running the db-sync node.
- Example SQL queries: Some example SQL and Haskell/Esqueleto queries.
- SchemaManagement: How the database schema is managed and modified.
- SQL DB Schema: The current PostgreSQL DB schema, as generated by the code.
- Validation: Explanation of validation done by the db-sync node and assumptions made.