title: Query on Indexing when Firestore collection has Timestamp field
body: <p>I have a Firestore project where my collection <code>feed</code> has a timestamp field <code>createdDate</code>. As I am querying the feeds based on the created time with other fields, I have created a <code>Composite Index</code> including the timestamp field.</p>
  <p>In the <a href="https://firebase.google.com/docs/firestore/query-data/index-overview#indexing_best_practices" rel="nofollow noreferrer">Indexing best practices</a> document the following is mentioned.</p>
  <blockquote>
  <p>If you index a field that increases or decreases sequentially between
  documents in a collection, like a timestamp, then the maximum write
  rate to the collection is 500 writes per second. If you don't query
  based on the field with sequential values, you can exempt the field
  from indexing to bypass this limit.</p>
  </blockquote>
  <p>As I am already using the timestamp field in a <code>Composite Index</code>, I can exempt the field from <code>Automatic Index Settings</code>. Will this bypass this limit of 500 writes per second in the collection or it will still be applied as the <code>Composite Index</code> is using the field. Please help me understand this.</p>