getDocComparator

Get a comparator that determines the sort order of docs within a single Reader.

NB We cannot simply use the FieldComparator API because it requires docIDs to be sent in-order. The default implementations allocate arraymaxDoc to hold native values for comparison, but 1) they are transient (only alive while sorting this one segment) and 2) in the typical index sorting case, they are only used to sort newly flushed segments, which will be smaller than merged segments

Parameters