The sample SQL missed product_name in group by, it should be:
select city, product_name, sum(1) as occurancy from fact_table where city
in ("abc") group by city, product_name order by occurancy desc limit 100;
To get a better understanding of TopN, please check
https://kylin.apache.org/blog/2016/03/19/approximate-topn-measure/
2017-04-02 22:33 GMT+08:00 ShaoFeng Shi <shaofeng...@apache.org>:
> Kylin TopN's "sum|order by" supports two options a) a numeric column, b)
> constant 1.
>
> The option b) can match your requirement in my understanding. You just
> need define "product_name" as the "group by" column in TopN, and constant 1
> as the "sum|order by" column; dont' forget to use "city" as cube's
> dimension, then you can fetch the top products with SQL like:
>
> select city, product_name, sum(1) as occurancy from fact_table where city
> in ("abc") group by city order by occurancy desc limit 100;
>
> If the "product_name" is a UHC column, you'd better use a non-dict
> encoding (like "fixed_length") method for it.
>
>
>
> 2017-04-01 9:07 GMT+08:00 Billy Liu <billy...@apache.org>:
>
>> group by SUM, or group by COUNT is reasonable and supported. There is no
>> order by name alphabetical support.
>>
>> 2017-03-31 20:16 GMT+08:00 hongbin ma <mahong...@apache.org>:
>>
>> > hi,
>> >
>> > i believe it's not supported. besides, how do you define "order" on
>> string?
>> > I don't think it's a reasonable requirement
>> >
>> > --
>> > Regards,
>> >
>> > *Bin Mahone | 马洪宾*
>> >
>>
>
>
>
> --
> Best regards,
>
> Shaofeng Shi 史少锋
>
>
--
Best regards,
Shaofeng Shi 史少锋
