admin.py

# Using django import_export with transactions
# the whole was about 40 minutes before change, now 5 minutes.

from import_export.utils import atomic_if_using_transaction
from django.db import connections, DEFAULT_DB_ALIAS
from django.core.exceptions import ImproperlyConfigured


class PubliResource(resources.ModelResource):
    use_transactions_in_dry_run = False  # <=====

    def import_data(self, dataset, dry_run=False, raise_errors=False,
                    use_transactions=None, collect_failed_rows=False, **kwargs):
        """
        Imports data from ``tablib.Dataset``. Refer to :doc:`import_workflow`
        for a more complete description of the whole import process.

        :param dataset: A ``tablib.Dataset``

        :param raise_errors: Whether errors should be printed to the end user
            or raised regularly.

        :param use_transactions: If ``True`` the import process will be processed
            inside a transaction.

        :param collect_failed_rows: If ``True`` the import process will collect
            failed rows.

        :param dry_run: If ``dry_run`` is set, or an error occurs, if a transaction
            is being used, it will be rolled back.
        """

        if use_transactions is None:
            use_transactions = self.get_use_transactions()

        connection = connections[DEFAULT_DB_ALIAS]
        supports_transactions = getattr(connection.features, "supports_transactions", False)

        if use_transactions and not supports_transactions:
            raise ImproperlyConfigured

        # using_transactions = (use_transactions or dry_run) and supports_transactions
        # Now it looks for local attribute to force no transaction mode <===
        using_transactions = supports_transactions and (
                                     use_transactions or
                                     (dry_run and self.use_transactions_in_dry_run)
                                     )

        with atomic_if_using_transaction(using_transactions):
            return self.import_data_inner(dataset, dry_run, raise_errors, using_transactions, collect_failed_rows, **kwargs)

    class Meta:
        model = Publi

settings.py

# other stuff ...

#Import Export
IMPORT_EXPORT_USE_TRANSACTIONS = False