ethan-tyler commented on issue #20135:
URL: https://github.com/apache/datafusion/issues/20135#issuecomment-3843522330

   > Does `filename(table.col)` resolve the ambiguity?
   
   @adriangb - `filename(table.col)` does resolve binding, but in joins you'd 
want both sides anyway. I'd view it as a convenience layer on top of the column 
model, not the core API.
   
   @jkylling - I like the direction, but I'm worried we can't actually stack 
extension types like 
`.with_extension_type(Hidden).with_extension_type(RowNumber)`. Arrow fields 
have a single extension type identity and the second call might overwrite the 
first.
   
   If that's the case, maybe visibility (`Hidden`) belongs in the field 
metadata, and we reserve extension types for materialization hints 
(`RowNumber`, `RowGroupIndex`, etc).
   
   Tags make it declarative but don't remove the need for consistent 
propagation through Projection/Join/SubqueryAlias.


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to