extended properties

• User only to add an extended property directly to a user or role
  = user只可直接向用户或角色添加扩展属性。
• The value of an extended property is a
  扩展属性值是
• Extended properties catalog views
  扩展属性目录视图
• User should only be used when you add an extended property to a user
  只能在为用户添加扩展属性时才应使用user 。
• Extended properties cannot be added to server - level event notifications
  扩展属性无法添加到服务器级别的事件通知。
• Extended properties provide only a named location in which to store data
  扩展属性仅提供在其中存储数据的指定位置。
• Replicating extended properties
  复制扩展属性
• To delete an extended property
  删除扩展属性
• To update an extended property
  更新扩展属性
• Extended properties can be defined for objects at any of these levels
  可以为这些级别中任一级别的对象定义扩展属性。