Re: the group key is retracted

Posted by Benchao Li-2 on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/the-group-key-is-retracted-tp36288p36291.html

Hi lec ssmi,

>  If the type value of a record is updated in the  database, the values before and after the update will be divided into different partitions and handed over to different operators for calculation.

I think your understanding is correct.

>  Can Retraction happen correctly?

I didn't get your point, can you elaborate your question a little bit?

lec ssmi <[hidden email]> 于2020年7月1日周三 上午9:54写道：

Hi:

  When we use sql for aggregation operation, for example, the following sql

       select count( distinct name) cnt, type  from table  group by type

  Source data can be regarded as bin log data.

  If the type value of a record is updated in the   database, the values before and after the update will be divided into different partitions and handed over to different operators for calculation. Can Retraction happen correctly?

--