This ticket introduces a change in the format used to report ambiguous paths in the updateDescription field of a change stream update event, superseding the work done in SERVER-63861. Full details of the new format are available in the Syntax document here.

Description of Linked Ticket

In PM-1950 / SERVER-63861, we exposed additional information about the paths reported by a change stream update operation. This was motivated by the fact that these paths can sometimes be ambiguous; for instance, a dot embedded in a fieldname was indistinguishable from a path separator, and there was no way to tell whether a numeric path component referred to an array index or a field name.

While the syntax we introduced does resolve these ambiguities, we were not entirely satisfied with the end result; we think it will be too cumbersome for users to work with. We therefore propose to rework the format ahead of its release in 6.1.