[GitHub] [druid] clintropolis commented on pull request #14236: add array_to_mv function to convert arrays into mvds to assist with migration from mvds to arrays

["clintropolis (via GitHub)" <gi...@apache.org>]

clintropolis commented on PR #14236:
URL: https://github.com/apache/druid/pull/14236#issuecomment-1543552218

   >I'm concerned about how good of a shim layer this really is given that it comes with a performance penalty. Likely, even with this, it's not really recommended to switch forward yet because of the performance penalty (or fear of one).
   
   >And, between the work of adding the virtual column versus doing an exhaustive validation that there isn't really a significant performance penalty, I think we should spend time on adding the virtual column and not try to quantify how much performance penalty comes from doing this as an expression.
   
   Totally agree, I plan to add specialized virtual column implementation for this function and also `MV_TO_ARRAY` asap, though this function would need to exist anyway, so this is primarily to start experimenting with an MVD to ARRAY migration path while I keep working on that stuff.
   


-- 
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: commits-unsubscribe@druid.apache.org

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


---------------------------------------------------------------------
To unsubscribe, e-mail: commits-unsubscribe@druid.apache.org
For additional commands, e-mail: commits-help@druid.apache.org