Ability to create the resume token based on oplog item
CHoose an oplog event to set the resume token for, instead of needing to run the change stream for system to create a resume token
Why: Concerns about many stream re-reading a full oplog if failure before finding first event
A customer would like to obtain the set of ChangeStream resume tokens for a particular point in time so that they can selectively resume using a particular resume token.
The startAtOperationTime feature of change streams uses a BSON timestamp, which has second-level granularity, and there could be many oplog entries within a second.
If we had an option to return all the documents (and their respective change stream resume tokens) in the oplog for a given timestamp, then the customer could perform additional filtering, (or the filter could also be part of the operation) and allow them to resume, more selectively.