Store component

This component persists the chain state in a sqlite database. It also stores each block's raw data as a file.

Mekle data structures are kept in-memory and are rebuilt on startup. Other data like account, note and nullifier information is always read from disk. We will need to revisit this in the future but for now this is performant enough.

Migrations

We have database migration support in place but don't actively use it yet. There is only the latest schema, and we reset chain state (aka nuke the existing database) on each release.

Note that the migration logic includes both a schema number and a hash based on the sql schema. These are both checked on node startup to ensure that any existing database matches the expected schema. If you're seeing database failures on startup its likely that you created the database before making schema changes resulting in different schema hashes.

Architecture

The store consists mainly of a gRPC server which answers requests from the RPC and block-producer components, as well as new block submissions from the block-producer.

A lightweight background process performs database query optimisation by analysing database queries and statistics.