title: How many BSON ObjectIds can a mongodb array field save
body: <p>I am planning to save huge number of ids for foreignkey ids in this array. So, I am just checking what would be the max number of BSON::ObjectIds I can save in the field array. Lets say for example </p>
  
  <pre><code>department_ids: [BSON::OBjectId('57cf6d6e8315292136000001'), BSON::OBjectId('57cf6d6e8315292136000002') ...... ]
  </code></pre>