# rubocop:disable RemoveIndex
class AddUniqueIndexToListsLabelId < ActiveRecord::Migration[4.2]
include Gitlab::Database::MigrationHelpers
DOWNTIME = false
disable_ddl_transaction!
def up
add_concurrent_index :lists, [:board_id, :label_id], unique: true
end
def down
remove_index :lists, column: [:board_id, :label_id] if index_exists?(:lists, [:board_id, :label_id], unique: true)