Optional removal of transaction and extra get() in get_or_create().

[Michael Korobov]

Our app's subject is accounting and it's processing a huge amount of different data by a large amount of users. Hence the perfomance takes crucial part in this app. We've been optimizing our code recently and discovered that get_or_create method of QuerySet is generating an atomic block with a savepoint, and then makes another query to a database in case of IntegrityError exception. While this is really great on it's own, it slows down the app.

The solution in attached PR is aimed to allow us to make a choice - whether to use get_or_created as it currently is, or skip the creation of an atomic block and avoid another possible hit to a database. New kwarg to get_or_create raw=False if set to True ignores both of mentioned components, making the method run faster. And if needed we can handle IntegrityError or make an atomic block where we indeed need it by ourselves.

[Michael Korobov]

​Pull Request
This has been approved by my teamleader, and the Django Test Suite passed successfully.

[Mariusz Felisiak]

Thanks for this ticket, however this use case is quite niche, IMO. I don't think that we want to encourage users for such "unsafe" behavior. get_or_create() is a sensitive method with few warnings (see ​documentation) we shouldn't make it more complicated. Moreover you should be able to easily add such hook to your app.

You can start a discussion on the DevelopersMailingList if you don't agree.

[Michael Korobov]

Thanks for your time and a reply. We will be keeping these changes as a patch in our app.