the group key is retracted

Posted by lec ssmi on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/the-group-key-is-retracted-tp36288.html

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?