Hello, I have created pull request to CALCITE-1531 <https://issues.apache.org/jira/browse/CALCITE-1531>: https://github.com/apache/calcite/pull/335. NULL in boolean operators in Calcite corresponds to Boolean type UNKNOWN, so when NULL is used in this operators, we shouldn't throw exception and continue query execution.
Could anyone please review it? Kind regards, Serhii Harnyk
