alamb commented on PR #13933:
URL: https://github.com/apache/datafusion/pull/13933#issuecomment-2565321646

   Hi @zhuqi-lucas  -- sorry if we caused confusion here. I agree with 
@berkaysynnada  and @ozankabak  that ordering information is already 
represented in plans using 
[`EquivalenceProperties`](https://docs.rs/datafusion/latest/datafusion/physical_expr/struct.EquivalenceProperties.html)
   
   - As I understand https://github.com/apache/datafusion/issues/13891:
   
   The idea is to store the output sorted order in the parquet file
   
   So this would look something like:
   1. `COPY (SELECT ... ORDER BY x, y) to 'foo.parquet'`
   2. `foo.parquet` has some new metadata like `DATAFUSION_ORDER_BY = `x ASC, y 
ASC`
   3. On the next `SELECT ... FROM 'foo.parquet'` the ParquetExec would look 
for the ` DATAFUSION_ORDER_BY` metadata in the file and if present update the 
`EquivalenceProperties` to reflect an ordering `x, y`
   
   Does that make sense?
   


-- 
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: github-unsubscr...@datafusion.apache.org

For queries about this service, please contact Infrastructure at:
us...@infra.apache.org


---------------------------------------------------------------------
To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org
For additional commands, e-mail: github-h...@datafusion.apache.org

Reply via email to