peter-toth commented on PR #58895:
URL: https://github.com/apache/spark/pull/58895#issuecomment-5820024251

   Thank you for the second round. It was as thorough as the first, and the 
individual replies carry the details.
   
   The comment that mattered most was the design question on treating the 
extracted filter as an optional hint. That is what the PR does now, and it went 
one step further than the suggestion: the conjunct is not moved out of the plan 
at all, it is copied. It stays in the post-scan `Filter`, so the reader may 
give a file or a row group up freely, and `UnsupportedFileReadException`, its 
case in the shared classifier and the hard failure on a page-index-less file 
are all gone.
   
   Two things settled that direction. The bloom is already built by the time 
the scan runs, so having the `Filter` use it regardless costs nothing extra and 
means it is never built for nothing. And whoever turns this conf on is doing it 
because the filter prunes a lot, so evaluating it a second time on the rows 
that survive is a small price rather than a regression.
   
   The description is rewritten around that, with a Design decisions section. 
It also now carries a measurement of splicing against re-reading the key 
columns, which answers your earlier question with numbers: re-reading transfers 
up to 49% more bytes than splicing, and more than the feature being off, 
because phase 1 has already read the key column once.
   
   Everything is in c255f88.


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