rdettai commented on pull request #1063:
URL: https://github.com/apache/arrow-datafusion/pull/1063#issuecomment-944285349


   I'm not sure this is a very well defined thing in the SQL standards, but 
usually in query engines, projected columns get default names. For instance the 
result value of `SELECT sum(a) FROM table` will be in a column named `SUM(a)` 
(or something like that). 
   
   If you start up the Datafusion CLI as explained in 
`datafusion-cli/README.md`, you will get:
   ```sql,ignore
   > SELECT count(*) FROM foo;
   +-----------------+
   | COUNT(UInt8(1)) |
   +-----------------+
   | 1               |
   +-----------------+
   ```
   
   ```sql,ignore
   > SELECT min(a) FROM foo;
   +------------+
   | MIN(foo.a) |
   +------------+
   | 1          |
   +------------+
   ```
   
   So what would you expect the column name to be for `SELECT count(a) FROM 
foo;`?
   
   Also, it would be pretty nice if the response column names were the same 
whether the plan went through an optimization or not 😄 
   
   _Side note_: I checked on Athena (if I remember correctly you are used to 
that engine), and their choice for example is to simply name the column 
`_col0`. 


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