Initially, the SBE ScanStage was created to provide an API for reading from a collection. However, because the scan stage is used in different ways (i.e. to scan an entire collection, seek to a record id and scan, and seek a range between record ids), the implementation of the stage has become somewhat complicated. As such, it may be worth refactoring this stage (similar to how was done for the index scan stage in SBE).
This ticket tracks the work to design and implement a refactor of the ScanStage in SBE.