In Oracle, the most efficient way to delete a row (if using a cursor
in SQL PL) is by rowid. Rowid is an internal unique identifier that
Oracle assigns to every row in a database. So you would open your
cursor by selecting rowid for the rows that you want to delete, then
do the delete by rowid.

Is there an equivalent to rowid in UDB for LUW? If not, what's the
most efficient way to delete a row? We're looking at multi-million
row purges, so I want to make sure I get this right.

Thanks.