BuildChildRequired returns the ordering that must be required of its given child in order to satisfy a required ordering.

BuildProvided returns a specific ordering that the operator provides (and which must be maintained on the results during distributed execution).

CanProvide returns true if the given operator returns rows that can satisfy the given required ordering.

ScanIsReverse returns true if the scan must be performed in reverse order in order to satisfy the required ordering.

ScanPrivateCanProvide returns true if the scan operator returns rows that satisfy the given required ordering; it also returns whether the scan needs to be in reverse order to match the required ordering.

StreamingGroupingCols returns the subset of grouping columns that form a prefix of the ordering required of the input.