I was looking into Error Prone [1] checking for Calcite and it found what looks like a bug in Druid Adapter. The output is as follows
DruidJsonFilter.java:[324,9] [IdentityBinaryExpression] A binary expression > where both operands are the same is usually incorrect; the value of this > expression is equivalent to `lhs.getType().getFamily() == > SqlTypeFamily.NUMERIC`. > [ERROR] (see > http://errorprone.info/bugpattern/IdentityBinaryExpression) The DruidJsonFilter [2] has left and right hand the exact same. Raising awareness here before going to JIRA. [1] http://errorprone.info/ [2] https://github.com/apache/calcite/blob/master/druid/src/main/java/org/apache/calcite/adapter/druid/DruidJsonFilter.java#L323 Kevin Risden
