@Override
  protected void serializeAttributes(DataOutputStream stream) throws IOException {
    PlanNodeType.CREATE_LOGICAL_VIEW.serialize(stream);
    // serialize other member variables for this node
    ReadWriteIOUtils.write(this.viewPathToSourceMap.size(), stream);
    for (Map.Entry<PartialPath, ViewExpression> entry : viewPathToSourceMap.entrySet()) {
      entry.getKey().serialize(stream);
      ViewExpression.serialize(entry.getValue(), stream);
    }
  }
This variable will be set in function splitByPartition() according to analysis. And it will be
set when creating new split nodes.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/planner/plan/node/metadata/write/view/CreateLogicalViewNode.java