Hi Gayathri,
If you only have the content shown, then note that your "b" columns are always
null. Drill has no way to know what type b is supposed to be. Normally, Drill
guesses Nullable Int.
I wonder, have you turned on the "store.json.all_text_mode" session option to
tell JSON to read all columns as VarChar? If so, that would explain why the
error message says that b is VarChar.
The team is in the process of adding a schema system to resolve this kind of
ambiguity: you'll be able to say, "b is a DOUBLE. Even if it is all nulls, go
ahead and treat it as double."
In the mean time, you can try Rahul's suggestion. Or, you can ensure that the b
column has actual data. Or, you can try casting the (NULL VarChar) b columns to
the desired type.
Thanks,
- Paul
On Tuesday, April 9, 2019, 4:32:13 PM PDT, Gayathri Selvaraj
<[email protected]> wrote:
Hi Team,
Facing some issues with the following case:
Json file (*sample.json*) is having the following content:
{"a":2,"b":null} {"a":2,"b":null} {"a":3,"b":null} {"a":4,"b":null}
*Query:*
SELECT a, sum(b) FROM dfs.`C:\\Users\\user\\Desktop
sample.json` group by a;
*Error:*
UNSUPPORTED_OPERATION ERROR: Only COUNT, MIN and MAX aggregate functions
supported for VarChar type
*Observation:*
If we query without using group by, then it is working fine without any
error. If group by is used, then sum of null values is throwing the above
error.
Can anyone please let us know the solution for this or if there are any
alternative. I have raised a JIRA ticket for the same -
https://issues.apache.org/jira/browse/DRILL-7161
Regards,
Gayathri
