@Override public RelNode visit(HiveProject rel) {
      if(!(hasRexOver(rel.getProjects()))) {
        mightRequireValueGen = false;
        return super.visit(rel);
      } else {
        mightRequireValueGen = true;
        return rel;
      }
    }
Returns whether there are any correlating variables in this statement.

@return whether there are any correlating variables
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/HiveRelDecorrelator.java