How to express the datatype of sparksql collect_list(named_struct(...)) in flinksql?

[vtygoss]

Hi, flink community!


I am working on migrating data production pipeline from SparkSQL to 
FlinkSQL(1.12.0). And i meet a problem about MULTISET<STRUCT<....>>.


```
Spark SQL


select COLLECT_LIST(named_struct('id', id, 'name', name)) as info
from table 
group by ...;


``` 


- 1. how to express and store this data structure in flink? 
I tried to express by MULTISET<ROW<id long, name string>> in FlinkSQL. But it 
seems that ORC / JSON / AVRO format cann't store this type. 
- 2.  How to read MULTISET<Row<id long, name string>> in FlinkSQL?  
If i need to define a function, which type should be briged to for 
MultiSet<Row<id long, name string>>?  


Is there any other way more convenient to solute this problem?   
Thanks very much for your any suggestions or replies. 


Best Regards!