Create multi not null constraint for exports

Prevent group and project ID from both being null.

Required as part of the sharding work for cells.

Changelog: performance

db/migrate/20241007162049_add_multi_not_null_constraint_to_bulk_import_exports.rb

+# frozen_string_literal: true
+
+class AddMultiNotNullConstraintToBulkImportExports < Gitlab::Database::Migration[2.2]
+  milestone '17.6'
+
+  disable_ddl_transaction!
+
+  def up
+    add_multi_column_not_null_constraint(:bulk_import_exports, :group_id, :project_id)
+  end
+
+  def down
+    remove_multi_column_not_null_constraint(:bulk_import_exports, :group_id, :project_id)
+  end
+end

db/schema_migrations/20241007162049

+6560d591cabfeda2a813ef521492af968e282c7d329b8cd9769ac9607fa32c4b
\ No newline at end of file

db/structure.sql

@@ -7983,7 +7983,8 @@ CREATE TABLE bulk_import_exports (
     user_id bigint,
     CONSTRAINT check_24cb010672 CHECK ((char_length(relation) <= 255)),
     CONSTRAINT check_8f0f357334 CHECK ((char_length(error) <= 255)),
-    CONSTRAINT check_9ee6d14d33 CHECK ((char_length(jid) <= 255))
+    CONSTRAINT check_9ee6d14d33 CHECK ((char_length(jid) <= 255)),
+    CONSTRAINT check_e84b7c0730 CHECK ((num_nonnulls(group_id, project_id) = 1))
 );
 CREATE SEQUENCE bulk_import_exports_id_seq

spec/factories/bulk_import/exports.rb

@@ -2,7 +2,7 @@
 FactoryBot.define do
   factory :bulk_import_export, class: 'BulkImports::Export', traits: %i[started] do
-    group
+    group { association(:group) if project.nil? }
     relation { 'labels' }
     trait :started do

spec/lib/gitlab/database/sharding_key_spec.rb

@@ -27,7 +27,6 @@
       'analytics_devops_adoption_segments.namespace_id',
       *['badges.project_id', 'badges.group_id'],
       *['boards.project_id', 'boards.group_id'],
-      *['bulk_import_exports.project_id', 'bulk_import_exports.group_id'],
       'ci_pipeline_schedules.project_id',
       'ci_sources_pipelines.project_id',
       'ci_triggers.project_id',