Oracle database supports the usage of "MINUS" keyword but calcite has not supported it yet.
Support INTERSECT, EXCEPT, MINUS, each with DISTINCT, ALL options
Resolved in release 1.11.0 (2017-01-11).
Fixed in http://git-wip-us.apache.org/repos/asf/calcite/commit/aa8fe082; thanks for the PR, Chandni Singh!
I quickly looked over your PR, and looks great. You've covered all the bases. I'll merge, and will commit after the avatica vote finishes.
(The travis failures are probably not your fault - travis is flaky - but if they are, I'll fix.)
Created pull request:
Add the keyword to the parser, add a method SqlConformance.allowMinus that returns true for Oracle, and check that parser throws if it's not Oracle. The implementation will be similar to the work done in CALCITE-1374.