private static OrderingScheme constructOrderingSchema(List<Symbol> symbols) {
    Map<Symbol, SortOrder> orderings = new HashMap<>();
    symbols.forEach(symbol -> orderings.put(symbol, SortOrder.ASC_NULLS_LAST));
    return new OrderingScheme(symbols, orderings);
  }
This class is used to generate distributed plan for table model.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/distribute/TableDistributedPlanGenerator.java