title: AWS SNS get topic by name
body: <p>I started to work with AWS SNS to send push notifications to my app. Today, to get a topic that I want to send push notifications to, I need to load all topics – using SNS client function listTopics() - and check each topic to see if the ARN has the name of the topic that I'm looking for. </p>
  
  <p>I think that it's a very inefficient way to get a topic ARN, and I'd like to know if there is a most efficient way to get this information, like a function getTopicByName or something else.</p>
  
  <p>If not, I'd like to know if ARN is immutable, and if can I store the topic ARN on my database?  </p>
  
  <p>Thanks.</p>