@Override
  public Operator visitSeriesSchemaFetchScan(
      SeriesSchemaFetchScanNode node, LocalExecutionPlanContext context) {
    OperatorContext operatorContext =
        context
            .getDriverContext()
            .addOperatorContext(
                context.getNextOperatorId(),
                node.getPlanNodeId(),
                SchemaFetchScanOperator.class.getSimpleName());
    return SchemaFetchScanOperator.ofSeries(
        node.getPlanNodeId(),
        operatorContext,
        node.getPatternTree(),
        node.getTemplateMap(),
        ((SchemaDriverContext) (context.getDriverContext())).getSchemaRegion(),
        node.isWithTags(),
        node.isWithAttributes(),
        node.isWithTemplate(),
        node.isWithAliasForce());
  }
This Visitor is responsible for transferring PlanNode Tree to Operator Tree.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/planner/OperatorTreeGenerator.java