Hive LEFT SEMI JOIN for 'NOT EXISTS'

Question

I have two tables with a single key column. Keys in table a are subset of all keys in table b. I need to select keys from table b that are NOT in table a.

Here is a

Answer 1

If you want results from table b, perhaps you can do the following instead?

  SELECT b.key FROM b LEFT OUTER JOIN a ON b.key = a.key WHERE a.key IS NULL;