1 files changed, 30 insertions, 0 deletions
diff --git a/db/post_migrate/20201103110018_schedule_merge_request_cleanup_schedules_backfill.rb b/db/post_migrate/20201103110018_schedule_merge_request_cleanup_schedules_backfill.rb
new file mode 100644
index 00000000000..77057205b09
--- /dev/null
+++ b/db/post_migrate/20201103110018_schedule_merge_request_cleanup_schedules_backfill.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+class ScheduleMergeRequestCleanupSchedulesBackfill < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  MIGRATION = 'BackfillMergeRequestCleanupSchedules'
+  DELAY_INTERVAL = 2.minutes
+  BATCH_SIZE = 10_000
+  TEMP_INDEX_NAME = 'merge_requests_state_id_temp_index'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :merge_requests, :id, name: TEMP_INDEX_NAME, where: "state_id IN (2, 3)"
+
+    eligible_mrs = Gitlab::BackgroundMigration::BackfillMergeRequestCleanupSchedules::MergeRequest.eligible
+
+    queue_background_migration_jobs_by_range_at_intervals(
+      eligible_mrs,
+      MIGRATION,
+      DELAY_INTERVAL,
+      batch_size: BATCH_SIZE
+    )
+  end
+
+  def down
+    remove_concurrent_index_by_name :merge_requests, TEMP_INDEX_NAME
+  end
+end