leanken commented on pull request #29104:
URL: https://github.com/apache/spark/pull/29104#issuecomment-659115253


   -- Test cases for multi-column ``WHERE a NOT IN (SELECT c FROM r ...)'':
   -- | # | does subquery include null?     | do filter columns contain null? | 
a = c? | b = d? | row included in result? |
   -- | 1 | empty                           | *                               | 
*      | *      | yes                     |
   -- | 2 | 1+ row has null for all columns | *                               | 
*      | *      | no                      |
   -- | 3 | no row has null for all columns | (yes, yes)                      | 
*      | *      | no                      |
   -- | 4 | no row has null for all columns | (no, yes)                       | 
yes    | *      | no                      |
   -- | 5 | no row has null for all columns | (no, yes)                       | 
no     | *      | yes                     |
   -- | 6 | no                              | (no, no)                        | 
yes    | yes    | no                      |
   -- | 7 | no                              | (no, no)                        | 
_      | _      | yes 
   
   multi column Not(IsNull) is much more complicated. i am afraid that the 
lookup code and if-else logic will be un-readable.


----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
[email protected]



---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to