Rich-T-kid commented on PR #24227:
URL: https://github.com/apache/datafusion/pull/24227#issuecomment-5698213418

   > These results reproduce the earlier performance direction. I think the 
implementation needs to avoid automatically promoting high-cardinality or 
dictionary-fallback columns.
   
   @kumarUjjawal  That is expected with this implementation. The larger epic 
#24111, specifically #24117, will handle deciding on a per-query basis whether 
to read the column in as Dictionary or as Utf8/Utf8View. The point of this 
feature flag is to let users enable direct RLE_DICTIONARY reads from Parquet 
files in DataFusion, for cases where they know the shape of their data and 
query well enough to make that decision themselves. By default, this flag will 
be turned off.
   
   This line of thinking is in line with what alamb mentioned here 
https://github.com/apache/datafusion/issues/24111#issuecomment-5206277128


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