Github user gatorsmile commented on the pull request:
https://github.com/apache/spark/pull/12736#issuecomment-215327600
Like `INTERSECT ALL`, `EXCEPT ALL` can be done by aggregation of the union
of the two tables. We can augment one table with a new column of constant `1`,
and the other with constant `-1`, then union the two tables, and find the row
satisfying the result of the `COUNT` and `SUM` of the new column.
Originally, I plan to do it after this release. All of you have more time
to review them. If we need to implement in this release, I can start writing
both `INTERSECT ALL` and `EXCEPT ALL` now.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
