title: MongoDB aggregation framework match OR
body: <p>Is it possible to do an OR in the $match? </p>
  
  <p>I mean something like this: </p>
  
  <pre><code>db.articles.aggregate(
      { $or: [ $match : { author : "dave" }, $match : { author : "john" }] }
  );
  </code></pre>