1 files changed, 33 insertions, 0 deletions
diff --git a/db/migrate/20190228092516_clean_up_noteable_id_for_notes_on_commits.rb b/db/migrate/20190228092516_clean_up_noteable_id_for_notes_on_commits.rb
new file mode 100644
index 00000000000..fe129e8f4dc
--- /dev/null
+++ b/db/migrate/20190228092516_clean_up_noteable_id_for_notes_on_commits.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class CleanUpNoteableIdForNotesOnCommits < ActiveRecord::Migration[5.0]
+  include Gitlab::Database::MigrationHelpers
+
+  # Set this constant to true if this migration requires downtime.
+  DOWNTIME = false
+
+  TEMP_INDEX_NAME = 'index_notes_on_commit_with_null_noteable_id'
+
+  disable_ddl_transaction!
+
+  def up
+    remove_concurrent_index_by_name(:notes, TEMP_INDEX_NAME)
+
+    add_concurrent_index(:notes, :id, where: "noteable_type = 'Commit' AND noteable_id IS NOT NULL", name: TEMP_INDEX_NAME)
+
+    # rubocop:disable Migration/UpdateLargeTable
+    update_column_in_batches(:notes, :noteable_id, nil) do |table, query|
+      query.where(
+        table[:noteable_type].eq('Commit').and(table[:noteable_id].not_eq(nil))
+      )
+    end
+
+    remove_concurrent_index_by_name(:notes, TEMP_INDEX_NAME)
+  end
+
+  def down
+  end
+end