alamb commented on issue #9083:
URL: https://github.com/apache/arrow-rs/issues/9083#issuecomment-3756356776

   My thoughts from the 
   1. https://github.com/apache/arrow-rs/issues/9083#issuecomment-3710183483
   2. https://github.com/apache/arrow-rs/issues/9083#issuecomment-3710188287
   
   Basically, my personal opinion is that a parallel RowFormat for equality 
comparisons is likely going to be a lot of code to maintain and I think that 
for whatever usecase you have in mind, you would likely better off using a 
different approach.
   
   > row format is also useful when you need to copy a lot of columns around, 
for example when shuffling
   
   I don't understand why row format would be used here -- Arrow already has a 
format that is optimzied for copying values around (the IPC format)
   
   
   > grouping - grouping by a lot of columns does not need ordering requirements
   
   How about implementing a specialization for Structs, the way we have for 
other types: 
https://github.com/apache/datafusion/tree/main/datafusion/physical-plan/src/aggregates/group_values/multi_group_by
   
   That would likely be a lot faster than having to copy all the data once 
which a new row format would do
   
   - aggregation - using count(distinct <struct>) or array_agg with distinct, 
both of which do not need ordering requirement
   shuffling
   
   Similarly, I think if you implemented a specialized accumulator for structs 
you would be better off than using a RowFormat, right?
   


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