Should you start out with Sharded or with a Non-Sharded MongoDB environment?
We suggest starting with Non-Sharded for simplicity and quick startup, unless your initial data set will not fit on single servers. Upgrading to Sharded from Non-sharded is easy and seamless, so there is not a lot of advantage in setting up Sharding before your data set is large.
🔗Reference : stackoverflow.com
🔗Source: Azure Interview Questions and Answers
