[GitHub] [druid] jon-wei opened a new issue #9326: Expressions should be able to generate a parseable string representation

[GitBox <gi...@apache.org>]

jon-wei opened a new issue #9326: Expressions should be able to generate a parseable string representation
URL: https://github.com/apache/druid/issues/9326
 
 
   Currently, if we have an Expr object and call toString(), e.g.:
   
   ```
       Expr expr = Parser.parse("concat(\"column\",'suffix')", TestExprMacroTable.INSTANCE);
       System.out.println(expr.toString());
   ```
   
   we can get a string representation that can't be reparsed into the same expression:
   
   ```
   (concat [column, suffix])
   ```
   
   It would be useful if the expressions supported this.
   
   One example where this could be useful is filter push down for join queries, where the filter optimization could benefit from being able to create virtual columns from expressions that appear in the join condition (https://github.com/apache/druid/pull/9301#discussion_r375029851)

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


With regards,
Apache Git Services

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