private static boolean validDataType(SqlDialect dialect, RexNode e) {
    try {
      RexVisitor<Void> visitor = new JdbcDataTypeValidatorVisitor(dialect);
      e.accept(visitor);
      return true;
    } catch (Util.FoundOne ex) {
      Util.swallow(ex, null);
      return false;
    }
  }
Returns whether a given expression contains only valid data types for this dialect.
ql/src/java/org/apache/hadoop/hive/ql/optimizer/calcite/rules/jdbc/JDBCProjectPushDownRule.java