englefly opened a new pull request, #16442:
URL: https://github.com/apache/doris/pull/16442

   # Proposed changes
   For performance reason, we want to remove constant column from groupingExprs.
   For example: `select 'abc', sum(a) from t group by 'abc'` is equivalent to 
`select 1, sum(a) from t`
   We can remove constant column `abc` from groupingExprs.
   But there is an exception:
        sql1: `select 'abc' from t group by 'abc'`
        sql2: `select 'abc' from t`
   sql1 is not equivalent to sql2.
   
   We need to keep some constant column if all items in groupingExprs are 
constant columns.
   
   Consider sql3 `select a from (select "abc" as a, 'def' as b) T group by b, 
a;`
   if the column is in select list, this column should not be removed.
   Issue Number: close #xxx
   
   ## Problem summary
   
   Describe your changes.
   
   ## Checklist(Required)
   
   1. Does it affect the original behavior: 
       - [ ] Yes
       - [ ] No
       - [ ] I don't know
   2. Has unit tests been added:
       - [ ] Yes
       - [ ] No
       - [ ] No Need
   3. Has document been added or modified:
       - [ ] Yes
       - [ ] No
       - [ ] No Need
   4. Does it need to update dependencies:
       - [ ] Yes
       - [ ] No
   5. Are there any changes that cannot be rolled back:
       - [ ] Yes (If Yes, please explain WHY)
       - [ ] No
   
   ## Further comments
   
   If this is a relatively large or complex change, kick off the discussion at 
[d...@doris.apache.org](mailto:d...@doris.apache.org) by explaining why you 
chose the solution you did and what alternatives you considered, etc...
   
   


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