title: NOTICES for sequence after running migration in rails on postgresql Application
body: <p>When i run my migration in Rails application on postgresql i got following NOTICES </p>
  
  <pre><code>NOTICE:  CREATE TABLE will create implicit sequence "notification_settings_id_seq" for serial column "notification_settings.id"
  NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "notification_settings_pkey" for table "notification_settings"
  </code></pre>
  
  <p>My migration file contains 088_create_notification_settings.rb</p>
  
  <pre><code>class CreateNotificationSettings &lt; ActiveRecord::Migration
    def self.up
      create_table :notification_settings do |t|
        t.integer :user_id
        t.integer :notification_id
        t.boolean :notification_on
        t.boolean :outbound
      end
    end
  
    def self.down
      drop_table :notification_settings
    end
  end
  </code></pre>
  
  <p>I would like to know </p>
  
  <p>what this NOTICES means?</p>
  
  <p>How to avoid this NOTICES?</p>
  
  <p>What will be the impact of such NOTICES on the Application if not avoided?</p>
  
  <p>Regards,</p>
  
  <p>Salil</p>