https://issues.apache.org/jira/secure/ReleaseNote.jspa?version=12341764&projectId=12315522
https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals
https://cwiki.apache.org/confluence/display/FLINK/FLIP-24+-+SQL+Client
https://github.com/apache/flink/pull/4471
SQL DDL
https://issues.apache.org/jira/browse/FLINK-7151
Support group window distinct aggregation on DataStream #5940
https://github.com/apache/flink/pull/5940
https://docs.google.com/document/d/1zj6OA-K2hi7ah8Fo-xTQB-mVmYfm6LsN2_NHgTCVmJI/edit#
Add user-defined function support in SQL Client
https://issues.apache.org/jira/browse/FLINK-8863
https://cwiki.apache.org/confluence/display/FLINK/FLIP-11%3A+Table+API+Stream+Aggregations