tieBreakerDirection

The direction of the unique key's fields that end this sort so it orders records totally, in a list, a page and a cursor alike: the direction of the sort's last field, ascending for an empty sort. Records tied on a descending sort so come in descending key order, and a sort whose fields all run one way is one index order, forward or backward (k DESC, key DESC is an index (k, key) read backward). Every backend that ends a sort with its key asks this.