Question

Point out the correct statement.

(a) Hashed keys do not work well with fields that increase monotonically like ObjectId values or timestamps

(b) If you shard an empty collection using a hashed shard key, MongoDB will automatically create and migrate chunks so that each shard has two chunks

(c) Hashed keys work well with ObjectId values only

(d) All of the mentioned

I had been asked this question by my school teacher while I was bunking the class.

Origin of the question is Sharded Cluster Behavior in portion Sharding Concepts, Mechanics and Sharded Cluster of MongoDB

Answer 1

The correct answer is (b) If you shard an empty collection using a hashed shard key, MongoDB will automatically create and migrate chunks so that each shard has two chunks

Explanation: Hashed keys work well with fields that increase monotonically like ObjectId values or timestamps.