Describe the enhancement requested

Currently, the sorting_columns is only defined on the RowGroupMetadata. This makes it hard to get the sort status of the entire file when it has more than one row group.

This makes it generally very hard to utilize during query optimization.

Is there any interest in adding sorting_columns to the FileMetadata optionally? I feel like this is more generally useful than having it on the row group metadata. I would be happy to draft up a proposal.