Earlier quoted context omitted.
> Improved transaction management¶ > Django’s transaction management was overhauled. Database-level autocommit is now turned on by default. This makes transaction handling more explicit and should improve performance. The existing APIs were deprecated, and new APIs were introduced, as described in the transaction management docs. > Please review carefully the list of known backwards-incompatibilities to determine if…
It's hard to imagine using an ORM for anything high volume that just got around to adding (still very limited) connection pooling. I'd tend to think anyone overly concerned with performance would use SQLAlchemy, if they use any ORM at all.
Or they did connection pooling outside the development framework.