@Override
  public Operator visitTableDeviceFetch(
      final TableDeviceFetchNode node, final LocalExecutionPlanContext context) {
    final OperatorContext operatorContext =
        context
            .getDriverContext()
            .addOperatorContext(
                context.getNextOperatorId(),
                node.getPlanNodeId(),
                SchemaQueryScanOperator.class.getSimpleName());
    return new SchemaQueryScanOperator<>(
        node.getPlanNodeId(),
        operatorContext,
        SchemaSourceFactory.getTableDeviceFetchSource(
            node.getDatabase(),
            node.getTableName(),
            node.getDeviceIdList(),
            node.getColumnHeaderList()));
  }
This Visitor is responsible for transferring Table PlanNode Tree to Table Operator Tree.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/planner/TableOperatorGenerator.java