The current implementation of change stream allow a user to:

• Start a change stream from the latest oplog entry
• Resume after or start after a resume token
• Start at a timestamp

If we use a token that is not in the oplog or the timestamp is outside the oplog range, the change stream will fail.

Once a failure happens, the user will have to restart the change stream.

Proposition:

• Add a method startAtFirst() which the MongoDB cluster would interpret as "start this change stream at the first oplog entry (oldest) that exists on a majority of nodes"

Thanks