zammad/db/migrate/20161228000001_add_taskbar_meta.rb

class AddTaskbarMeta < ActiveRecord::Migration[4.2]
  def up
    # return if it's a new setup
    return if !Setting.exists?(name: 'system_init_done')

    add_column :taskbars, :preferences, :text, limit: 5.megabytes + 1, null: true
    add_index :taskbars, [:key]

    Cache.clear
  end
end