[sonthonax]

The inability to batch network calls in a single unit of work makes the ORM needlessly slow. That's also one of the main advantages to managing transactions/session yourself. It can save a huge number of round trips in a complex view.

The Django ORM itself is also slow at generating SQL. Recently I was bemused by a query, which took 500us to actually be generated. This wasn't doing anything particular wild, it just had a `select_related` call to an object that had about 50 fields (not great DB design, but beyond my control). The query actually took longer to build than it did to run.

That itself wouldn't be an issue if you could LRU cache the SQL query itself. But you can't, it's Django.