1 files changed, 31 insertions, 0 deletions
diff --git a/db/post_migrate/20220420061450_backfill_null_note_discussion_ids.rb b/db/post_migrate/20220420061450_backfill_null_note_discussion_ids.rb
new file mode 100644
index 00000000000..8880bc2f748
--- /dev/null
+++ b/db/post_migrate/20220420061450_backfill_null_note_discussion_ids.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+class BackfillNullNoteDiscussionIds < Gitlab::Database::Migration[2.0]
+  MIGRATION = 'BackfillNoteDiscussionId'
+  DELAY_INTERVAL = 2.minutes
+  BATCH_SIZE = 10_000
+
+  restrict_gitlab_migration gitlab_schema: :gitlab_main
+
+  disable_ddl_transaction!
+
+  class Note < MigrationRecord
+    include EachBatch
+
+    self.table_name = 'notes'
+    self.inheritance_column = :_type_disabled
+  end
+
+  def up
+    queue_background_migration_jobs_by_range_at_intervals(
+      Note.where(discussion_id: nil),
+      MIGRATION,
+      DELAY_INTERVAL,
+      batch_size: BATCH_SIZE
+    )
+  end
+
+  def down
+    # no-op
+  end
+end