fathomdb-schema

The on-disk schema and versioned migration registry for FathomDB, a local-first embedded retrieval engine built on SQLite.

Is this the crate you want?

Probably not, unless you are working on FathomDB rather than with it. Applications should depend on fathomdb; the engine pulls this crate in and runs migrations for you at Engine::open.

This crate is published separately because it is a leaf — it depends only on rusqlite — and because it is the useful thing to reach for when you need to reason about a FathomDB database file without opening an engine: inspecting a database's schema version, checking whether a file is at a version your build understands, or writing tooling over the canonical tables.

Status: pre-1.0, beta

The 0.8.x line is under active development. The public surface can change between minor releases. The on-disk format is versioned and migrated forward, but there is no downgrade path: a database migrated by a newer build cannot be opened by an older one.

What it contains

SCHEMA_VERSION — the schema version this build migrates to, and the value it writes into SQLite's user_version pragma.
MIGRATIONS — the ordered, append-only migration registry. Each entry is a named step; the registry is accretion-checked, so an already-released step cannot be edited in place.
migrate, migrate_with_steps, migrate_with_event_sink — run pending migrations against a rusqlite::Connection, returning a MigrationReport (per-step names and timings) or a typed MigrationError / MigrationFailureReport.
bootstrap_steps and CANONICAL_TABLES — the initial schema and the canonical table set.
File-suffix constants (SQLITE_SUFFIX, WAL_SUFFIX, LOCK_SUFFIX, JOURNAL_SUFFIX) and PRAGMA_USER_VERSION, which together describe the on-disk footprint of one database.

Install

cargo add fathomdb-schema

License

MIT. See the LICENSE file shipped in this crate.