title: When to use transients, when not to?
body: <p>I'm using Wordpress and developed some site-specific plugins for it, additionally my theme is customized to fit the requirements of the plugins in the backend.</p>
  
  <p>The last days I fiddled with transients in Wordpress. In some tutorials they're saying "<em>If your're using custom queries and their results are cachable: Use a transient</em>". Sounds good but I'm wondering when to use transients to get a real advantage.
  I mean, even when using transients there have to be at least two queries in the background, haven't it? The first one for checking the validity, second one for the transient itself.</p>
  
  <p>So is it really useful to use a transient i.e. for a custom WP_Query?
  Thanks a lot for your help and thoughts.</p>