title: is the operation getLastRequestStatistics on Cosmos DB (using Mongo API) free of charge?
body: <p>This question is based on the info provided by Microsoft at <a href="https://learn.microsoft.com/en-us/azure/cosmos-db/mongodb/find-request-unit-charge-mongodb?tabs=java-driver" rel="nofollow noreferrer">https://learn.microsoft.com/en-us/azure/cosmos-db/mongodb/find-request-unit-charge-mongodb?tabs=java-driver</a>
  I ran a find query using mongo driver and immediately run twice the runCommand described in the documentation. I was expecting the first to return the cost in RUs of the first find command and the second the cost of the cost query, but I receive the same value twice.</p>
  <pre><code>mongoRepository.find ... (whatever)
  
  Document stats = database.runCommand(new Document(&quot;getLastRequestStatistics&quot;, 1));
  Double requestCharge = stats.getDouble(&quot;RequestCharge&quot;);
  
  Document stats2 = database.runCommand(new Document(&quot;getLastRequestStatistics&quot;, 1));
  Double requestCharge2 = stats2.getDouble(&quot;RequestCharge&quot;);
  </code></pre>
  <p>then <code>requestCharge == requestCharge2</code></p>
  <p>Does it mean the operation is free? or there is a charge? I see no clue in the documentation linked above.</p>