Cardano DB-Sync
A core component of Cardano. Storing and organizing the blockchain data into a PostgreSQL database.
Cardano DB-Sync connects to the local Cardano node, traces on-chain activity, syncs with it, and stores blockchain data, not including cryptographic signatures, in a SQL relational database. The user can then use multiple tools to query this database the most common being Cardano GraphQL.
Part of the "official" Cardano technology stack from IOG