title: Is it possible to temporarily disable an Oracle database link
body: <p>Here is the situation.
  We have an Oracle 11g database where one schema user has a private database link to a remote database. When the user initiates a certain process, it pulls a large amount of data across and slows down the other applications. We would like to limit when this user can access this remote database by disabling the database link during certain times of the day and then enable it when performance is not an issue.
  I have not been able to find a way short of locking the user or dropping the database link to do this. Changing the open_links system parameter, I believe, requires a restart and that affects the other database links as well.</p>
  
  <p>Does anyone have a clever way to implement this kind of restriction?
  Thank you in advance.</p>