[jira] [Commented] (KYLIN-1377) TopN measure should support more expressions

["logicigam (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/KYLIN-1377?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15411586#comment-15411586 ] 

logicigam commented on KYLIN-1377:
----------------------------------

not only max,min,we need to select  topN on a count measure and count(distinct) measure also.

> TopN measure should support more expressions
> --------------------------------------------
>
>                 Key: KYLIN-1377
>                 URL: https://issues.apache.org/jira/browse/KYLIN-1377
>             Project: Kylin
>          Issue Type: New Feature
>    Affects Versions: v1.4.0
>            Reporter: Shaofeng SHI
>            Assignee: Shaofeng SHI
>             Fix For: Backlog
>
>
> TopN should support not only SUM, but also MAX, MIN as the expression.
> A possible case is, find out the sellers which sold the top expensive items:
> select seller_id, max(price) from sals_records where region = 'US' and year = '2015' order by max(price) desc limit 100;
> In the future, more parameter should be supported
> 1) the expression (default SUM); 2) the soring order (default Desc). 3) the encoding method:
> A sample is:
> {code}
> {
>     "name" : "TOP_SELLER",
>     "function" : {
>       "expression" : "TOP_N",
>       "parameter" : {
>         "id": 0,
>         "type" : "column",
>         "value" : "PRICE",
>         "next_parameter" : {
>           "id": 1,
>           "type" : "column",
>           "value" : "SELLER_ID",
>           "next_parameter" : {
>              "id": 2,
>             "type" : "",
>             "value" : "SUM",
>             "next_parameter" : {
>               "id": 3,
>               "type" : "",
>               "value" : "DESC"
>                 "next_parameter" : {
>                  "id": 4,
>                 "type" : "",
>                 "value" : "dict"
>             }
>             }
>         }
>       },
>       "returntype" : "topn(100)"
>     },
> {code}



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)