private ComparisonFilter.Operator convertExpressionOperator2SchemaOperator(
      final ComparisonExpression.Operator operator, final boolean isOrdered) {
    switch (operator) {
      case NOT_EQUAL:
        return ComparisonFilter.Operator.NOT_EQUAL;
      case LESS_THAN:
        return isOrdered
            ? ComparisonFilter.Operator.LESS_THAN
            : ComparisonFilter.Operator.GREATER_THAN;
      case LESS_THAN_OR_EQUAL:
        return isOrdered
            ? ComparisonFilter.Operator.LESS_THAN_OR_EQUAL
            : ComparisonFilter.Operator.GREATER_THAN_OR_EQUAL;
      case GREATER_THAN:
        return isOrdered
            ? ComparisonFilter.Operator.GREATER_THAN
            : ComparisonFilter.Operator.LESS_THAN;
      case GREATER_THAN_OR_EQUAL:
        return isOrdered
            ? ComparisonFilter.Operator.GREATER_THAN_OR_EQUAL
            : ComparisonFilter.Operator.LESS_THAN_OR_EQUAL;
      default:
        throw new UnsupportedOperationException("Unsupported operator " + operator);
    }
  }
The {@link ConvertSchemaPredicateToFilterVisitor} will convert a predicate to {@link
SchemaFilter}. For the predicates which can not be converted, this will return {@code null}.
However, for IdDeterminedPredicate, this visitor shall never return {@code null}.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/analyzer/predicate/schema/ConvertSchemaPredicateToFilterVisitor.java