Mongodb changestream getmore runs as collscans

How do we handle mongodb change stream queries with getmore queries that are running as collscans on the server. Is there a way to avoid collscans ? Or is there a way to reduce the impact of changestreams on performance.

Changestreams do not do a traditional COLLSCAN because they are not querying any of your collections, they are watching/querying the oplog, a special system collection also used for replication.

Can you explain what’s behind your question since changestream getmore usually just gets data from the tail end of the oplog. What’s the reason that you think it’s impacting your performance?

Asya