I got the idea it's the null value in Hive. 0: jdbc:hive2://localhost:10000/default> select size(null);
+------+ | _c0 | +------+ | -1 | +------+ Thanks On Sun, Feb 27, 2022 at 4:02 PM Bitfox <bit...@bitfox.top> wrote: > what does this -1 value mean? > > > set mapred.reduce.tasks; > > +-------------------------+ > > | set | > > +-------------------------+ > > | mapred.reduce.tasks=-1 | > > +-------------------------+ > > 1 row selected (0.014 seconds) >