[Answered ]-Django 1.10 Delete large cascade querySet

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1👍

First of all you can change the timeout time of MySQL by edditing settings.py

DATABASES = {
    'default': {
        ...
        OPTIONS = {
            'connect_timeout': 5, # your timeout time
        }
        ...
    }
}

The reasons why .delete() may be slow are:

  1. Django has to ensure cascade deleting functions properly. It has to look for foreign keys to your models
  2. Django has to somehow handle pre and post-save signals for your models

If you are sure that your models don’t have cascade deleting or any signals to be handled, you can try to use private _raw_delete as follows:

queryset._raw_delete(queryset.db)

You can find more details on it here

👤pythad

1👍

Finally I got a simple solution to delete all cascade object breaking down the macro deletion operation preferring delete Fund objects one by one. Because it is a really long operation (approximately 1 second for each object for thousands objects) I assigned it to a celery worker. Slow but safe I think, if someone got a better solution please let me know!

@shared_task
def reset_funds():
    for fund in Fund.objects.all():
        print "Delete Fund: {}".format(fund.name)
        fund.delete()
    return "All Funds Deleted!"
👤Andrea

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