ArchiveBox/archivebox/misc/paginators.py

31 lines
1.2 KiB
Python

__package__ = 'archivebox.misc'
from django.core.paginator import Paginator
from django.utils.functional import cached_property
class AccelleratedPaginator(Paginator):
"""
Accellerated Pagniator ignores DISTINCT when counting total number of rows.
Speeds up SELECT Count(*) on Admin views by >20x.
https://hakibenita.com/optimizing-the-django-admin-paginator
"""
@cached_property
def count(self):
if self.object_list._has_filters(): # type: ignore
# fallback to normal count method on filtered queryset
return super().count
else:
# otherwise count total rows in a separate fast query
return self.object_list.model.objects.count()
# Alternative approach for PostgreSQL: fallback count takes > 200ms
# from django.db import connection, transaction, OperationalError
# with transaction.atomic(), connection.cursor() as cursor:
# cursor.execute('SET LOCAL statement_timeout TO 200;')
# try:
# return super().count
# except OperationalError:
# return 9999999999999