Opened 23 months ago

Last modified 23 months ago

#33848 closed Cleanup/optimization

Migration StateApps.clone deepcopy too many objects — at Version 1

Reported by: Iuri de Silvio Owned by: nobody
Component: Migrations Version: 4.0
Severity: Normal Keywords:
Cc: Simon Charette Triage Stage: Ready for checkin
Has patch: yes Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no

Description (last modified by Iuri de Silvio)

StateApps.clone execute two slow deep copies. The first one copy all models. The second one copy app configs, that include all apps and the specific app models.

In my application, with ~250 models, this deepcopy is around 5% of migration time. I was able to cleanup StateApps before copy, to not copy all models and apps every operation again. After the optimization, it takes less than 1% of migration time.

​https://github.com/django/django/blob/d4c5d2b52c897ccc07f04482d3f42f976a79223c/django/db/migrations/state.py#L683

Change History (1)

comment:1 by Iuri de Silvio, 23 months ago

Description: modified (diff)
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