cartodb-4.42/db/migrate/20160718095625_change_user_max_layers_default.rb

Sequel.migration do
  up do
    alter_table :users do
      set_column_default :max_layers, 8
    end
  end

  down do
    alter_table :users do
      set_column_default :max_layers, 4
    end
  end
end