text: import operator
  
  from django.db import InterfaceError
  from django.db.backends.base.features import BaseDatabaseFeatures
  from django.utils.functional import cached_property
  
  
  class DatabaseFeatures(BaseDatabaseFeatures):
      minimum_database_version = (11,)
      allows_group_by_selected_pks = True
      can_return_columns_from_insert = True
      can_return_rows_from_bulk_insert = True
      has_real_datatype = True
      has_native_uuid_field = True
      has_native_duration_field = True
      has_native_json_field = True
      can_defer_constraint_checks = True
      has_select_for_update = True
      has_select_for_update_nowait = True
      has_select_for_update_of = True
      has_select_for_update_skip_locked = True
      has_select_for_no_key_update = True
      can_release_savepoints = True
      supports_tablespaces = True
      supports_transactions = True
      can_introspect_materialized_views = True
      can_distinct_on_fields = True
      can_rollback_ddl = True
      supports_combined_alters = True
      nulls_order_largest = True
      closed_cursor_error_class = InterfaceError
      greatest_least_ignores_nulls = True
      can_clone_databases = True
      supports_temporal_subtraction = True
      supports_slicing_ordering_in_compound = True
      create_test_procedure_without_params_sql = """
          CREATE FUNCTION test_procedure () RETURNS void AS $$
          DECLARE
              V_I INTEGER;
          BEGIN
              V_I := 1;
          END;
      $$ LANGUAGE plpgsql;"""
      create_test_procedure_with_int_param_sql = """
          CREATE FUNCTION test_procedure (P_I INTEGER) RETURNS void AS $$
          DECLARE
              V_I INTEGER;
          BEGIN
              V_I := P_I;
          END;
      $$ LANGUAGE plpgsql;"""
      requires_casted_case_in_updates = True
      supports_over_clause = True
      only_supports_unbounded_with_preceding_and_following = True
      supports_aggregate_filter_clause = True
      supported_explain_formats = {"JSON", "TEXT", "XML", "YAML"}
      supports_deferrable_unique_constraints = True
      has_json_operators = True
      json_key_contains_list_matching_requires_list = True
      supports_update_conflicts = True
      supports_update_conflicts_with_target = True
      supports_covering_indexes = True
      test_collations = {
          "non_default": "sv-x-icu",
          "swedish_ci": "sv-x-icu",
      }
      test_now_utc_template = "STATEMENT_TIMESTAMP() AT TIME ZONE 'UTC'"
  
      django_test_skips = {
          "opclasses are PostgreSQL only.": {
              "indexes.tests.SchemaIndexesNotPostgreSQLTests."
              "test_create_index_ignores_opclasses",
          },
      }
  
      @cached_property
      def introspected_field_types(self):
          return {
              **super().introspected_field_types,
              "PositiveBigIntegerField": "BigIntegerField",
              "PositiveIntegerField": "IntegerField",
              "PositiveSmallIntegerField": "SmallIntegerField",
          }
  
      @cached_property
      def is_postgresql_12(self):
          return self.connection.pg_version >= 120000
  
      @cached_property
      def is_postgresql_13(self):
          return self.connection.pg_version >= 130000
  
      @cached_property
      def is_postgresql_14(self):
          return self.connection.pg_version >= 140000
  
      has_bit_xor = property(operator.attrgetter("is_postgresql_14"))
      supports_covering_gist_indexes = property(operator.attrgetter("is_postgresql_12"))
      supports_covering_spgist_indexes = property(operator.attrgetter("is_postgresql_14"))
      supports_non_deterministic_collations = property(
          operator.attrgetter("is_postgresql_12")
      )
  