title: When is it possible to change the subnet group within AWS RDS?
body: <p>I have one Oracle SE instance that is not multi-az and does not have encryption enabled, and I have an Oracle EE instance that is multi-az and has encryption enabled. The former has the option to change the subnet group through the console (modify instance > network and security), whereas the latter does not. Both instances are in a subnet group within the default vpc, and I have a custom vpc within the same account with another subnet group in it. </p>
  
  <p>What conditions determine whether or not it is possible to change the subnet group of an RDS instance? I have not been able to find any documentation on this so far. </p>