message: wip: update comment
diff: @@ -507,7 +507,12 @@ public:
  // TODO this is an issue for httpfs: we're doing head requests + fetching metadata while locking global state.
  // this is mega slow for metadata-heavy reads across many files
  // The issue however is that we need the batch index depends on the metadata of previous files and you cannot know the batch index
  - // TODO: can we just use upper/lower bytes for file/rowgroup to circumvent this?
  + // However: we don't need to know the batch index for reading the metadata, just read metadata, then go through files again for
  + // a row group to scan.
  + // So we can just:
  + // If there's a row group to be scanned, scan it
  + // Elif theres files left, setup the reader for the file, then recheck for row groups.
  + // Else, done
  // Plan:
  