[GitHub] [arrow-datafusion] alamb commented on a diff in pull request #5997: Don't use parquet file offset for file range pruning

["alamb (via GitHub)" <gi...@apache.org>]

alamb commented on code in PR #5997:
URL: https://github.com/apache/arrow-datafusion/pull/5997#discussion_r1165940245


##########
datafusion/core/src/physical_plan/file_format/parquet/row_groups.rs:
##########
@@ -53,7 +53,11 @@ pub(crate) fn prune_row_groups(
     let mut filtered = Vec::with_capacity(groups.len());
     for (idx, metadata) in groups.iter().enumerate() {
         if let Some(range) = &range {
-            let offset = metadata.column(0).file_offset();
+            let col = metadata.column(0);

Review Comment:
   Given how subtle this is and the lack of test coverage, I think a comment is in order:
   ```suggestion
              // figure out where the first dictionary page (or first data page are)
              // note don't use the location of metadata 
              // <https://github.com/apache/arrow-datafusion/issues/5995>
               let col = metadata.column(0);
   ```



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