Schema migrations don't create indexes
The code to add an index is tested, so I believe adding an index explicitly should work. You can check the `test_add_index` test-case in `test_migrate.py`. Call Model.create_table().  Or, oddly, database.create_tables([Model]). The database.create_table method will only create the table, though, whereas create_tables() creates both tables and indexes. I've tested this with v2.8.6 and definitely fixed for the schema migration utils @coleifer Yes sorry I removed my comment without updating.

`database.create_tables([])` do create both table and indexes but `database.create_table` does not.
If you're doing a migration and add a column with `index=True` or `unique=True` it doesn't automatically create an index. Even trying to perform a `migrator.add_index()` in the same `migrate()` block fails.

I'm doing this with the Postgres backend.