This video shows the steps required to change a DocumentDB collection from using pre-defined performance to user-defined performance in the Azure Portal. Changing the performance level from pre-defined to user-defined enables you to customize the throughput that DocumentDB reserves for your application.

For more information about performance levels, see Performance levels in DocumentDB, or for written instructions of the steps in this video, see Changing performance levels using the Azure Portal. 

If your application requires more than 10GB of storage per collection, or more than 10,000 RU/s of throughput, you can change your collection from a single partition collection to a partitioned collection. For more information about changing to a partitioned collection, see Migrating from single-partition to partitioned collections.