@Override
  public RelDataType deriveDecimalPlusType(
      RelDataTypeFactory typeFactory, RelDataType type1, RelDataType type2) {
    return deriveDecimalType(
        typeFactory, type1, type2, LogicalTypeMerging::findAdditionDecimalType);
  }
Custom type system for Flink.

<p>Copied from flink-1.18.
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/planner/calcite/FlinkTypeSystem.java