class RemoveOldReblogIndexOnStatuses < ActiveRecord::Migration[5.1] disable_ddl_transaction! def up # This index may not exists (see migration 20171122120436) remove_index :statuses, [:account_id, :reblog_of_id] if index_exists?(:statuses, [:account_id, :reblog_of_id]) remove_index :statuses, :reblog_of_id end def down add_index :statuses, :reblog_of_id, algorithm: :concurrently end end