* Add `Model.bulk_update()` method for bulk-updating fields across multiple
model instances. [Docs](http://docs.peewee-orm.com/en/latest/peewee/api.htmlModel.bulk_update).
* Add `lazy_load` parameter to `ForeignKeyField`. When initialized with
`lazy_load=False`, the foreign-key will not use an additional query to
resolve the related model instance. Instead, if the related model instance is
not available, the underlying FK column value is returned (behaving like the
"_id" descriptor).
* Added `Model.truncate_table()` method.
* The `reflection` and `pwiz` extensions now attempt to be smarter about
converting database table and column names into snake-case. To disable this,
you can set `snake_case=False` when calling the `Introspector.introspect()`
method or use the `-L` (legacy naming) option with the `pwiz` script.
* Bulk insert via ``insert_many()`` no longer require specification of the
fields argument when the inserted rows are lists/tuples. In that case, the
fields will be inferred to be all model fields except any auto-increment id.
* Add `DatabaseProxy`, which implements several of the `Database` class context
managers. This allows you to reference some of the special features of the
database object without directly needing to initialize the proxy first.
* Add support for window function frame exclusion and added built-in support
for the GROUPS frame type.
* Add support for chaining window functions by extending a previously-declared
window function.
* Playhouse Postgresql extension `TSVectorField.match()` method supports an
additional argument `plain`, which can be used to control the parsing of the
TS query.
* Added very minimal `JSONField` to the playhouse MySQL extension.

[View commits](https://github.com/coleifer/peewee/compare/3.9.3...3.9.4)