redmine/db/migrate/20091220184736_add_indexes_to_issue_status.rb

class AddIndexesToIssueStatus < ActiveRecord::Migration[4.2]
  def self.up
    add_index :issue_statuses, :position
    add_index :issue_statuses, :is_closed
    add_index :issue_statuses, :is_default
  end

  def self.down
    remove_index :issue_statuses, :position
    remove_index :issue_statuses, :is_closed
    remove_index :issue_statuses, :is_default
  end
end