sqlalchemy drops tables in order of dependency, where by “dependency” we mean foreign key dependencies..you can declare these explicitly using the ForeignKey construct. But table reflection already uses the PG system tables to get this information automatically (we used to use information_schema but it proved to be too slow and quirky). this feature can be used to drop all tables in the correct order like so:

engine = create_engine(”posgres://user:pass@host/db”)
meta = MetaData(engine)
meta.reflect()
meta.drop_all()

however, it currently doesn’t cover sequences except for those which were created implicitly using SERIAL columns…we might add support for reflection of external sequences eventually.

- mike