title: Firestore indexes pricing
body: <p>I have a question about Firestore Indexing pricing. I've setup an index in a collection for a &quot;tags&quot; array field with timestamp descending and wondering if this will cost anything. I am aware that the actual storage taken up by the index will cost something, but are there any other fees like firestore reads that should be taken into account?</p>
  <p>Thanks so much!</p>