sqlite

Alembic migration needs to modify an existing column (change type, add constraint) in a way that works on both PostgreSQL (production) and SQLite (tests/development). PostgreSQL supports ALTER COLUMN ...

Need to run Alembic migrations that work on both PostgreSQL and SQLite. SQLite doesn't support ALTER TABLE for column renames or type changes, causing migration failures in test environments.

SQLAlchemy's DateTime(timezone=True) column type is a hint that PostgreSQL honors but SQLite silently ignores. Values stored via datetime.now(UTC) are persisted without timezone info in SQLite and ret...

SQLite databases running in WAL journal mode (default in modern SQLite, and what most application embeddings use) hold recent writes in `<dbname>-wal` and `<dbname>-shm` sidecar files until a checkpoi...