Question

Which field does not support TTL indexes?

(a) _identity

(b) _option

(c) _id

(d) None of the mentioned

I had been asked this question during an online interview.

I would like to ask this question from Data from Collections in division Monitoring MongoDB and Optimization Strategies for MongoDB of MongoDB

Answer 1

The correct option is (c) _id

For explanation I would say: You cannot create a TTL index on a capped collection because MongoDB cannot remove documents from a capped collection.