maropu commented on pull request #29983:
URL: https://github.com/apache/spark/pull/29983#issuecomment-706148055
Really, we need to return 0.0 in the case? Looks PostgreSQL/MySQL returns
null instead;
```
mysql> create table t (v float8);
mysql> insert into t values (1.0);
mysql> SELECT stddev_samp(v) FROM t;
+----------------+
| stddev_samp(v) |
+----------------+
| NULL |
+----------------+
1 row in set (0.00 sec)
postgres=# create table t (v float8);
postgres=# insert into t values (1.0);
INSERT 0 1
postgres=# \pset null 'null'
Null display is "null".
postgres=# SELECT stddev_samp(v) FROM t;
stddev_samp
-------------
null
(1 row)
```
----------------------------------------------------------------
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:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
