title: Performance when using Filter.Where using the MongoDB C# driver
body: <p>Say you have the following line of code:</p>
  
  <pre><code>var filter = Builders&lt;BsonDocument&gt;.Filter.Where(t =&gt; t.id == myId);
  var result = collection.Find(filter).ToList();
  </code></pre>
  
  <p>Does the filter builder translate the lambda to a literal $where clause or does it optimize it to use the $eq clause? $where has slow performance so I don't want to use it if there's no translation. </p>
  
  <p>This is a simple example but we have other queries in our code that are lengthier but would easily translate to non-$where queries.</p>