Advice on sharding the Parse Server _User collection?

Question

The out-of-the-box _User collection in Mongo for Parse Server has a unique index on both username and email. Given that, what's the ideal strategy for sharding this collection? My initial plan was to just use _id (not hashed) but obviously that doesn't work with the unique indexes.

Answer 1

You can shard it by "_id": "hashed", but it will give the warning Can't ensure unique email or username or something of that sort.