orca.migrationsThe schema's migrations (State.migrate applies them): each version's statements, which versions raise the floor an older binary needs, and the check that an older binary may run on a newer schema. AGENTS.md says how to keep a migration additive.
data_version_sqldef data_version_sql(describe: String) -> StringSQL for the data version of the describe JSON describe (a jsonb expression): its steps' version= as <step>=<version>, by step name, comma-separated; empty when no step sets one (#297). The fill takes a partition done under another code as done only when this matches (orca.fill).
migration_floordef migration_floor(version: Int) -> IntThe fewest migrations a binary must know to run on a database at schema version version: the newest floor-raising migration up to it.
known_migrationsdef known_migrations() -> IntHow many migrations this binary knows: all of _migrations, or fewer under ORCA_TEST_MIGRATIONS=N, which the tests use to act as an older binary on a database a newer one migrated.
schema_aheaddef schema_ahead(have: Int, floor: Int, known: Int) -> BoolWhether a binary that knows known migrations runs on a database at schema version have without migrating it: False when the database isn't ahead (the binary applies what it lacks), True when it's ahead with only additive migrations since (floor, the fewest migrations the database says a binary must know, is at most known). Raises when the database needs a newer binary, or doesn't say (floor < 0).