avantgardnerio commented on issue #7191:
URL: 
https://github.com/apache/arrow-datafusion/issues/7191#issuecomment-1665672090

   > Perhaps we could add a redact group API to the new row accumulators, this 
would allow using them for this as well as for window functions
   
   I struggled with this for a bit. Originally I rejected using 
`GroupValuesRows` because it had a hash table in it, whereas this needed to be 
ordered. Eventually I realized I needed a BiMap and ended up with both a hash 
table (group to value) and a priority queue (value to group). I think this 
means we could merge the two implementations by passing an optional limit to 
`GroupValuesRows`. 
   
   I don't think we'd want to always evict groups, because we might not even 
need to add them in the first place if the value being aggregated is 
less/greater than the min/max of the priority queue - so it would be a no-op.


-- 
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]

Reply via email to