[GitHub] [arrow-datafusion] andrei-ionescu edited a comment on issue #1383: Reading nested parquet files results in `index out of bounds`

[GitBox <gi...@apache.org>]

andrei-ionescu edited a comment on issue #1383:
URL: https://github.com/apache/arrow-datafusion/issues/1383#issuecomment-984597063


   I've been looking at the source code and it seems that the statistics are taken into account only for the top level columns. In the majority of places I see `schema.fields()` were `schema` is Arrow schema and `fields()` returns only top level fields.
   
   Parquet, on the other side have statistics for all columns, regardless of the nested level.
   
   I do understand the "quick and dirty workaround" and in regards to it I have the following questions:
   
   1. Is datafusion query engine using the column stats?
   2. What about writing parquet files? Shouldn't those file be written with stats for all columns?
   


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