• Short review
• Show a migration script with aggregation
  
• Talk about Migration scripts

• Feature Switches
• Migration Scripts
• Pay As You Go
• Versioning

• Pipeline
• Pipes objects through a unix pipe like fashion
• Expressions
• Similar to SQL statements - allows document manipulation and calculations

cmd = { aggregate: 'assessments',
        pipeline: [
          {
            '$project' => {
              :_id => 0,
              :user_id => 1,
              :organization_id => 1,
              :assessment_id => "$_id",
              :supplemental_question_ids => 1,
              :question_ids => 1,
              :response_count => 1,
              :date => 1,
              :end_date => 1,
              :released => 1,
              :viewing_key => 1,
            }
          }
        ]
      }