  We study here preference revision, considering both the monotonic case where
the original preferences are preserved and the nonmonotonic case where the new
preferences may override the original ones. We use a relational framework in
which preferences are represented using binary relations (not necessarily
finite). We identify several classes of revisions that preserve order axioms,
for example the axioms of strict partial or weak orders. We consider
applications of our results to preference querying in relational databases.
