tustvold commented on issue #3922:
URL: https://github.com/apache/arrow-rs/issues/3922#issuecomment-1482890381

   >  I do not think it is possible to select the last N rows subject to a 
predicate with a RowSelection.
   
   Correct, 
[RowFilter](https://docs.rs/parquet/latest/parquet/arrow/arrow_reader/struct.RowFilter.html)
 is the machinery that underpins late materialization, which is what would be 
necessary here. The output of this process is a `RowSelection` that is then 
used to read the output columns.
   
   Although now that I write this, whilst there is a mechanism to limit this 
final computed `RowSelection` to the [first N 
rows](https://docs.rs/parquet/latest/parquet/arrow/arrow_reader/struct.ArrowReaderBuilder.html#method.with_limit),
 there isn't a public API to limit this to the last N rows. This should be a 
very simple addition, I'll add it to my list.


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