title: How to check (fast) if a federated table is connected?
body: <p>I have 5 federated tables. Each table is connected to another database. Now I do some stuff in a loop and the first thing I do in the loop is some stuff with the federated table. Because the database to which the federated table is linked is not always online I have a error handler which catches the error when the database is offline. </p>
  
  <p>Unfortunately when the database is offline the query (a simple select query) takes about 5 seconds before it returns a error that the database is not online. If the database is then online I skip the rest of the code in the loop. </p>
  
  <p>Now my problem is is that that routine needs to be executed every 5 seconds and needs to be finished in 5 seconds. However when the databases are offline to which the federated table is linked then it the failed attemps to connect to the database takes up:
  5 db's * 5 sec = 25 seconds</p>
  
  <p>So my question is it possible to check very fast in SQL if the database to which the federated table is linked to is online?</p>